Updates IfcAxis2PlacementLinear and matrix4::init per @aothms suggestions

Fixed a bug when a summary cost has no sum applied.
Added Currency in table header.
Cleanup.
Added guards for end summary.

.github/scripts/publish-bonsai-releases.py

@@ -0,0 +1,95 @@
+#!/usr/bin/env -S uv run
+# /// script
+# dependencies = [
+#     "PyGithub",
+#     "requests",
+# ]
+# ///
+
+import os
+from pathlib import Path
+
+import requests
+from github import Github
+from github.GitReleaseAsset import GitReleaseAsset
+
+EXTENSION_ID = "bonsai"
+CURRENT_PYTHON_VERSION = "py313"
+CURRENT_PLATFORMS = ["linux-x64", "macos-arm64", "windows-x64"]
+
+
+def publish_asset(asset: GitReleaseAsset, token: str, repo_root: Path) -> None:
+    """
+    Publish an asset to Blender Extensions.
+    Reference: https://extensions.blender.org/api/v1/swagger
+    """
+    temp_path = repo_root / asset.name
+
+    response = requests.get(asset.browser_download_url)
+    response.raise_for_status()
+    temp_path.write_bytes(response.content)
+
+    url = f"https://extensions.blender.org/api/v1/extensions/{EXTENSION_ID}/versions/upload/"
+    headers = {"Authorization": f"Bearer {token}"}
+
+    files = {"version_file": temp_path.read_bytes()}
+    response = requests.post(url, headers=headers, files=files)
+    response.raise_for_status()
+
+    temp_path.unlink()
+
+    print(f"✓ Published {asset.name}")
+
+
+def main() -> None:
+    token = os.getenv("BLENDER_EXTENSIONS_TOKEN")
+    if not token:
+        raise Exception("BLENDER_EXTENSIONS_TOKEN environment variable not set")
+
+    # Get the repository root
+    repo_root = Path(__file__).parent.parent.parent
+
+    # Read VERSION file
+    version_file = repo_root / "VERSION"
+    version = version_file.read_text().strip()
+
+    print(f"Current VERSION: {version}")
+
+    tag_name = f"bonsai-{version}"
+
+    # Get release from GitHub
+    gh = Github()
+    gh_repo = gh.get_repo("IfcOpenShell/IfcOpenShell")
+    release = gh_repo.get_release(tag_name)
+
+    assets = release.get_assets()
+
+    asset_platform_map: dict[str, tuple[GitReleaseAsset, str]] = {}
+    for asset in assets:
+        if CURRENT_PYTHON_VERSION not in asset.name:
+            continue
+        for platform in CURRENT_PLATFORMS:
+            if platform in asset.name:
+                asset_platform_map[asset.name] = (asset, platform)
+                break
+
+    if len(asset_platform_map) != len(CURRENT_PLATFORMS):
+        found_platforms = {platform for _, (_, platform) in asset_platform_map.items()}
+        missing_platforms = set(CURRENT_PLATFORMS) - found_platforms
+        raise Exception(
+            f"Expected {len(CURRENT_PLATFORMS)} assets but found {len(asset_platform_map)}. "
+            f"Missing: {', '.join(sorted(missing_platforms))}"
+        )
+
+    print("\nRelease assets:")
+    for asset_name in sorted(asset_platform_map.keys()):
+        print(f"- {asset_name}")
+
+    # https://extensions.blender.org/api/v1/swagger
+    print("\nPublishing assets to Blender Extensions:")
+    for asset_name, (asset, platform) in asset_platform_map.items():
+        publish_asset(asset, token, repo_root)
+
+
+if __name__ == "__main__":
+    main()

.github/workflows/build_osx.yml

@@ -53,7 +53,7 @@ jobs:
           python ../nix/cache_dependencies.py unpack
 
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: mac-${{ matrix.arch }}
 

.github/workflows/build_pyodide.yml

@@ -29,7 +29,7 @@ jobs:
           python ../IfcOpenShell/nix/cache_dependencies.py unpack
 
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: ubuntu-22.04-${{ runner.arch }}
 

.github/workflows/build_rocky.yml

@@ -9,6 +9,13 @@ jobs:
     container: rockylinux:9
 
     steps:
+      - name: Set up uv
+        uses: astral-sh/setup-uv@37802adc94f370d6bfd71619e3f0bf239e1f3b78 # v7.6.0
+
+      - name: Install Python
+        # Installs latest Python version so it's preferred by uv over Rocky's system Python.
+        run: uv python install
+
       - name: Install Dependencies
         run: |
           dnf update -y
@@ -17,7 +24,6 @@ jobs:
                          sqlite-devel bzip2-devel zlib-devel openssl-devel xz-devel      \
                          readline-devel ncurses-devel libffi-devel libuuid-devel git-lfs \
                          findutils xz byacc
-          python3 -m pip install typing_extensions
           git config --global --add safe.directory '*'
 
       - name: Install aws cli
@@ -45,10 +51,10 @@ jobs:
       - name: Unpack Dependencies
         run: |
           cd build
-          python3 ../nix/cache_dependencies.py unpack
+          uv run ../nix/cache_dependencies.py unpack
 
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: ubuntu-22.04-${{ runner.arch }}-rockylinux9
 
@@ -56,7 +62,7 @@ jobs:
         shell: bash
         run: |
           set -o pipefail
-          CXXFLAGS="-O3" CFLAGS="-O3 ${DARWIN_C_SOURCE}" ADD_COMMIT_SHA=1 BUILD_CFG=Release python3 ./nix/build-all.py -v --diskcleanup 2>&1 | tee build.log
+          CXXFLAGS="-O3" CFLAGS="-O3 ${DARWIN_C_SOURCE}" ADD_COMMIT_SHA=1 BUILD_CFG=Release uv run ./nix/build-all.py -v --diskcleanup 2>&1 | tee build.log
 
       - name: Upload Build Logs
         if: always()
@@ -71,7 +77,7 @@ jobs:
       - name: Pack Dependencies
         run: |
           cd build
-          python3 ../nix/cache_dependencies.py pack
+          uv run ../nix/cache_dependencies.py pack
 
       - name: Commit and Push Changes to Build Repository
         run: |

.github/workflows/build_rocky_arm.yml

@@ -9,6 +9,13 @@ jobs:
     container: arm64v8/rockylinux:9
 
     steps:
+      - name: Set up uv
+        uses: astral-sh/setup-uv@37802adc94f370d6bfd71619e3f0bf239e1f3b78 # v7.6.0
+
+      - name: Install Python
+        # Installs latest Python version so it's preferred by uv over Rocky's system Python.
+        run: uv python install
+
       - name: Install Dependencies
         run: |
           dnf update -y
@@ -17,7 +24,6 @@ jobs:
                          sqlite-devel bzip2-devel zlib-devel openssl-devel xz-devel      \
                          readline-devel ncurses-devel libffi-devel libuuid-devel git-lfs \
                          findutils xz byacc
-          python3 -m pip install typing_extensions
           git config --global --add safe.directory '*'
 
       - name: Install aws cli
@@ -45,10 +51,10 @@ jobs:
       - name: Unpack Dependencies
         run: |
           cd build
-          python3 ../nix/cache_dependencies.py unpack
+          uv run ../nix/cache_dependencies.py unpack
 
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: ubuntu-22.04-${{ runner.arch }}-rockylinux9
 
@@ -56,7 +62,7 @@ jobs:
         shell: bash
         run: |
           set -o pipefail
-          CXXFLAGS="-O3" CFLAGS="-O3 ${DARWIN_C_SOURCE}" ADD_COMMIT_SHA=1 BUILD_CFG=Release python3 ./nix/build-all.py -v --diskcleanup 2>&1 | tee build.log
+          CXXFLAGS="-O3" CFLAGS="-O3 ${DARWIN_C_SOURCE}" ADD_COMMIT_SHA=1 BUILD_CFG=Release uv run ./nix/build-all.py -v --diskcleanup 2>&1 | tee build.log
 
       - name: Upload Build Logs
         if: always()
@@ -71,7 +77,7 @@ jobs:
       - name: Pack Dependencies
         run: |
           cd build
-          python3 ../nix/cache_dependencies.py pack
+          uv run ../nix/cache_dependencies.py pack
 
       - name: Commit and Push Changes to Build Repository
         run: |

.github/workflows/build_win.yml

@@ -52,7 +52,7 @@ jobs:
           }
 
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: win-${{ matrix.arch }}
           # Windows ccache needs ~1GB

.github/workflows/ci-bonsai-daily.yml

@@ -109,7 +109,7 @@ jobs:
           # Ensure Bonsai and ifcsverchok enable/disable works before uploading to extensions repo.
 
           # Download Blender.
-          wget -q -O blender.tar.xz https://download.blender.org/release/Blender5.0/blender-5.1.0-linux-x64.tar.xz
+          wget -q -O blender.tar.xz https://download.blender.org/release/Blender5.1/blender-5.1.0-linux-x64.tar.xz
           tar -xf blender.tar.xz
 
           # Setup Blender.
@@ -122,7 +122,7 @@ jobs:
           pip install -r requirements.txt
           python setup_extensions_repo.py --last-tag
           cd ..
-          bonsai_zip="$(pwd)/$(ls bonsai_unstable_repo/bonsai_py311*-linux-x64.zip)"
+          bonsai_zip="$(pwd)/$(ls bonsai_unstable_repo/bonsai_py313*-linux-x64.zip)"
 
           # Install Bonsai.
           blender --command extension install-file -r user_default -e $bonsai_zip

.github/workflows/ci-bonsai.yml

@@ -24,7 +24,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        pyver: [py311, py312]
+        pyver: [py311, py312, py313]
         config:
           - {
             name: "Windows Build",
@@ -42,6 +42,11 @@ jobs:
             name: "MacOS ARM Build",
             short_name: macosm1,
           }
+        exclude:
+          # Python 3.13 is needed for Blender 5.1+ and Blender dropped Intel Mac support in 5.0.
+          - pyver: py313
+            config:
+              short_name: macos
     steps:
       - uses: actions/checkout@v6
       - uses: actions/setup-python@v6 # https://github.com/actions/setup-python

.github/workflows/ci-ifcopenshell-docker.yml

@@ -35,7 +35,7 @@ jobs:
 
     -
       name: ccache
-      uses: hendrikmuhs/ccache-action@v1.2.22
+      uses: hendrikmuhs/ccache-action@v1.2.23
 
     - 
       name: Build ifcopenshell

.github/workflows/ci-lint.yaml

@@ -1,4 +1,4 @@
-name: ci-black-formatting
+name: ci-lint
 
 on:
   push:
@@ -30,6 +30,7 @@ jobs:
           uv tool install ruff
           uv tool install black
           uv tool install poethepoet
+          uv tool install ty==0.0.34
 
       # black doesn't catch all syntax errors, so we check them explicitly.
       - name: Check syntax errors
@@ -57,6 +58,13 @@ jobs:
           black --diff --check . | black-codeclimate | python .github/workflows/black_to_github_annotations.py
         continue-on-error: true
 
+      - name: ty check
+        id: ty
+        run: |
+          poe ty-venv
+          poe ty
+        continue-on-error: true
+
       - name: Ruff check
         id: ruff
         run: |
@@ -87,8 +95,7 @@ jobs:
             echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
           }
 
-          run_check poe ruff-main
-          run_check poe ruff-old
+          run_check poe ruff
 
           exit $ERROR
         continue-on-error: true
@@ -105,4 +112,7 @@ jobs:
           if [ "${{ steps.ruff.outcome }}" != "success" ]; then
             echo "::error::Ruff check failed, see Summary or 'ruff' step for the details." && ERROR=1
           fi
+          if [ "${{ steps.ty.outcome }}" != "success" ]; then
+            echo "::error::ty check failed, see 'ty check' step for the details." && ERROR=1
+          fi
           exit $ERROR

.github/workflows/ci-pyodide-wasm-release.yml

@@ -0,0 +1,46 @@
+name: Release Pyodide WASM Wheel
+
+on:
+  workflow_dispatch:
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout IfcOpenShell
+        uses: actions/checkout@v6
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v7
+
+      - name: Build wheel
+        working-directory: pyodide
+        run: uv run pack_wheel.py --build
+
+      - name: Find wheel
+        id: wheel
+        run: |
+          WHEEL=$(ls pyodide/dist/ifcopenshell-*.whl)
+          echo "path=$WHEEL" >> $GITHUB_OUTPUT
+          echo "name=$(basename $WHEEL)" >> $GITHUB_OUTPUT
+
+      - name: Checkout wasm-wheels
+        uses: actions/checkout@v6
+        with:
+          repository: IfcOpenShell/wasm-wheels
+          path: wasm-wheels
+          token: ${{ secrets.BUILD_REPO_TOKEN }}
+
+      - name: Commit and push wheel to wasm-wheels
+        run: |
+          WHEEL_NAME="${{ steps.wheel.outputs.name }}"
+          cp "${{ steps.wheel.outputs.path }}" "wasm-wheels/$WHEEL_NAME"
+          cd wasm-wheels
+          git config user.name "IfcOpenBot"
+          git config user.email "ifcopenbot@ifcopenshell.org"
+          git add "$WHEEL_NAME"
+          git commit -m "Add $WHEEL_NAME"
+          VERSION=$(cat ../VERSION)
+          git tag "v${VERSION}"
+          git push origin main
+          git push origin "v${VERSION}"

.github/workflows/ci.yml

@@ -51,7 +51,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install xmlschema xsdata numpy lxml pytest isodate lark networkx tabulate python-dateutil shapely
+          pip install xmlschema xsdata numpy lxml pytest isodate lark networkx tabulate python-dateutil shapely pyparsing
           pip install src/bcf --no-deps
           pip install pytest-xdist==3.8.0
 
@@ -79,7 +79,7 @@ jobs:
           libhdf5-dev libcgal-dev libeigen3-dev
           
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: ubuntu-22.04-${{ runner.arch }}
 

.github/workflows/docs-deployment.yml

@@ -1,36 +0,0 @@
-name: Build and Deploy Stable Documentation
-
-on:
-  workflow_dispatch:  # Manual trigger
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v6
-
-      - name: Set up Python
-        uses: actions/setup-python@v6
-        with:
-          python-version: '3.x'
-
-      - name: Install dependencies
-        run: |
-          cd src/bonsai/docs
-          pip install -r requirements.txt  # Run pip install from the docs directory
-
-      - name: Build documentation
-        run: |
-          cd src/bonsai/docs
-          make html
-
-      - name: Deploy to GitHub Pages (Stable)
-        uses: peaceiris/actions-gh-pages@v4
-        with:
-          deploy_key: ${{ secrets.ACTIONS_DEPLOY_KEY }}
-          external_repository: IfcOpenShell/bonsaibim_org_docs
-          publish_branch: main
-          cname: docs.bonsaibim.org
-          publish_dir: src/bonsai/docs/_build/html

.github/workflows/publish-aichat-app.yaml

@@ -32,7 +32,7 @@ jobs:
           submodules: recursive
           fetch-depth: 0
       - name: Checkout intermediate Pages repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: IfcOpenShell/aichat_ifcopenshell_org_static_html
           ref: gh-pages
@@ -42,7 +42,7 @@ jobs:
         run: |
           rsync -av --delete --exclude='.git/' src/ifcchat/ output/
       - name: Setup Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: "3.x"
       - name: Download wheels

.github/workflows/publish-bonsai-releases.yml

@@ -0,0 +1,16 @@
+name: Publish Bonsai Releases
+
+on:
+  workflow_dispatch:
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: astral-sh/setup-uv@v7
+
+      - run: uv run .github/scripts/publish-bonsai-releases.py
+        env:
+          BLENDER_EXTENSIONS_TOKEN: ${{ secrets.BLENDER_EXTENSIONS_TOKEN }}

.github/workflows/publish-pyodide-demo-app.yml

@@ -32,7 +32,7 @@ jobs:
           submodules: recursive
           fetch-depth: 0
       - name: Checkout intermediate Pages repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: IfcOpenShell/wasm_ifcopenshell_org_static_html
           ref: gh-pages

README.md

@@ -53,11 +53,11 @@ Contents
 | [ifcedit](https://docs.ifcopenshell.org/ifcedit.html)                   | CLI wrapper for ifcopenshell.api IFC model mutation functions         | LGPL-3.0-or-later   | [![PyPI](https://img.shields.io/pypi/v/ifcedit?label=PyPI&color=006dad)](https://pypi.org/project/ifcedit/) |
 | [ifcfm](https://docs.ifcopenshell.org/ifcfm.html)                     | Extract IFC data for FM handover requirements                         | LGPL-3.0-or-later   | [![PyPI](https://img.shields.io/pypi/v/ifcfm?label=PyPI&color=006dad)](https://pypi.org/project/ifcfm/) |
 | [ifcmax](https://docs.ifcopenshell.org/ifcmax.html)                    | Historic extension for IFC support in 3DS Max                         | LGPL-3.0-or-later\* | [![Official](https://img.shields.io/badge/IfcOpenShell.org-Download-70ba35)](https://docs.ifcopenshell.org/ifcmax.html)
-| [ifcmcp](https://docs.ifcopenshell.org/ifcmcp.html)                    | MCP server for querying and editing IFC building models               | LGPL-3.0-or-later   | [![PyPI](https://img.shields.io/pypi/v/ifcmcp?label=PyPI&color=006dad)](https://pypi.org/project/ifcmcp/) |
-| [ifcopenshell-python](https://docs.ifcopenshell.org/ifcopenshell-python.html)       | Python library for IFC manipulation                                   | LGPL-3.0-or-later\* | [![Official](https://img.shields.io/badge/IfcOpenShell.org-Download-70ba35)](https://docs.ifcopenshell.org/ifcopenshell-python/installation.html) [![GitHub](https://img.shields.io/github/v/release/ifcopenshell/ifcopenshell?filter=ifcopenshell-python-*&label=GitHub&color=f6f8fa)](https://github.com/IfcOpenShell/IfcOpenShell/releases?q=ifcopenshell-python&expanded=true) [![PyPI](https://img.shields.io/pypi/v/ifcopenshell?label=PyPI&color=006dad)](https://pypi.org/project/ifcopenshell/) [![Anaconda](https://img.shields.io/conda/vn/conda-forge/ifcopenshell?label=Anaconda&color=43b02a)](https://anaconda.org/conda-forge/ifcopenshell) [![Anaconda](https://img.shields.io/conda/vn/ifcopenshell/ifcopenshell?label=Anaconda-Unstable&color=43b02a)](https://anaconda.org/ifcopenshell/ifcopenshell) [![Docker](https://img.shields.io/docker/pulls/aecgeeks/ifcopenshell?label=Docker&color=1D63ED)](https://hub.docker.com/r/aecgeeks/ifcopenshell) [![AUR](https://img.shields.io/aur/version/ifcopenshell?label=AUR&color=1793d1)](https://aur.archlinux.org/packages/ifcopenshell) [![AUR Unstable](https://img.shields.io/aur/version/ifcopenshell-git?label=AUR-Unstable&color=1793d1)](https://aur.archlinux.org/packages/ifcopenshell-git) [Pyodide WASM Wheels](https://github.com/IfcOpenShell/wasm-wheels#pyodide-test-wheels) |
+| [ifcmcp](https://docs.ifcopenshell.org/ifcmcp.html)                    | MCP server for querying and editing IFC building models               | LGPL-3.0-or-later   | [![PyPI](https://img.shields.io/pypi/v/ifcopenshell-mcp?label=PyPI&color=006dad)](https://pypi.org/project/ifcopenshell-mcp/) |
+| [ifcopenshell-python](https://docs.ifcopenshell.org/ifcopenshell-python.html)       | Python library for IFC manipulation                                   | LGPL-3.0-or-later\* | [![Official](https://img.shields.io/badge/IfcOpenShell.org-Download-70ba35)](https://docs.ifcopenshell.org/ifcopenshell-python/installation.html) [![GitHub](https://img.shields.io/github/v/release/ifcopenshell/ifcopenshell?filter=ifcopenshell-python-*&label=GitHub&color=f6f8fa)](https://github.com/IfcOpenShell/IfcOpenShell/releases?q=ifcopenshell-python&expanded=true) [![PyPI](https://img.shields.io/pypi/v/ifcopenshell?label=PyPI&color=006dad)](https://pypi.org/project/ifcopenshell/) [![Anaconda](https://img.shields.io/conda/vn/conda-forge/ifcopenshell?label=Anaconda&color=43b02a)](https://anaconda.org/conda-forge/ifcopenshell) [![Anaconda](https://img.shields.io/conda/vn/ifcopenshell/ifcopenshell?label=Anaconda-Unstable&color=43b02a)](https://anaconda.org/ifcopenshell/ifcopenshell) [![Docker](https://img.shields.io/docker/pulls/aecgeeks/ifcopenshell?label=Docker&color=1D63ED)](https://hub.docker.com/r/aecgeeks/ifcopenshell) [![AUR](https://img.shields.io/aur/version/ifcopenshell?label=AUR&color=1793d1)](https://aur.archlinux.org/packages/ifcopenshell) [![AUR Unstable](https://img.shields.io/aur/version/ifcopenshell-git?label=AUR-Unstable&color=1793d1)](https://aur.archlinux.org/packages/ifcopenshell-git) [![Pyodide WASM Wheels tag](https://img.shields.io/github/v/tag/ifcopenshell/wasm-wheels?sort=semver&label=pyodide-wasm-wheels)](https://github.com/IfcOpenShell/wasm-wheels) |
 | [ifcpatch](https://docs.ifcopenshell.org/ifcpatch.html)                  | Utility to run pre-packaged scripts to manipulate IFCs                | LGPL-3.0-or-later   | [![PyPI](https://img.shields.io/pypi/v/ifcpatch?label=PyPI&color=006dad)](https://pypi.org/project/ifcpatch/) |
 | [ifcquery](https://docs.ifcopenshell.org/ifcquery.html)                  | CLI tool for querying and inspecting IFC building models              | LGPL-3.0-or-later   | [![PyPI](https://img.shields.io/pypi/v/ifcquery?label=PyPI&color=006dad)](https://pypi.org/project/ifcquery/) |
-| [ifcsverchok](https://docs.ifcopenshell.org/ifcsverchok.html)               | Blender Add-on for visual node programming with IFC                   | GPL-3.0-or-later    | [![GitHub Unstable](https://img.shields.io/github/v/release/ifcopenshell/ifcopenshell?filter=ifcsverchok-*.*.*.*&label=GitHub-Unstable&color=f6f8fa)](https://github.com/IfcOpenShell/IfcOpenShell/releases?q=ifcsverchok&expanded=true)
+| [ifcsverchok](https://docs.ifcopenshell.org/ifcsverchok.html)               | Blender Add-on for visual node programming with IFC                   | GPL-3.0-or-later    | [![GitHub](https://img.shields.io/github/v/release/ifcopenshell/ifcopenshell?filter=ifcsverchok-*.*.*&label=GitHub&color=f6f8fa)](https://github.com/IfcOpenShell/IfcOpenShell/releases?q=ifcsverchok&expanded=true)
 | [ifctester](https://docs.ifcopenshell.org/ifctester.html)                 | Library, CLI and webapp for IDS model auditing                        | LGPL-3.0-or-later   | [![PyPI](https://img.shields.io/pypi/v/ifctester?label=PyPI&color=006dad)](https://pypi.org/project/ifctester/) |
 
 The IfcOpenShell C++ codebase is split into multiple interal libraries:

VERSION

@@ -1 +1 @@
-0.8.5
+0.8.6

nix/build-all.py

@@ -1,4 +1,6 @@
 #!/usr/bin/python
+# /// script
+# ///
 ###############################################################################
 #                                                                             #
 # This file is part of IfcOpenShell.                                          #
@@ -124,16 +126,9 @@ ssl._create_default_https_context = ssl._create_unverified_context
 import time
 from collections.abc import Generator, Sequence
 from pathlib import Path
+from typing import Literal, Union
 from urllib.request import urlretrieve
 
-try:
-    from typing import Literal, Union
-except:
-    # python 3.6 compatibility for rocky 8
-    from typing import Union
-
-    from typing_extensions import Literal
-
 logger = logging.getLogger(__name__)
 logger.setLevel(logging.INFO)
 ch = logging.StreamHandler()
@@ -1094,10 +1089,19 @@ if "python" in targets and not USE_CURRENT_PYTHON_VERSION and "wasm" not in flag
             f"http://www.python.org/ftp/python/{PYTHON_VERSION}/",
             f"Python-{PYTHON_VERSION}.tgz",
         )
-        python_bin = INSTALL_DIR / f"python-{PYTHON_VERSION}" / "bin" / "python3"
+        python_install = INSTALL_DIR / f"python-{PYTHON_VERSION}"
+        python_bin = python_install / "bin" / "python3"
         # `_ssl` module is present -> we will be able to install `numpy` later
         # to verify IfcOpenShell installation
-        run([str(python_bin), "-c", "import _ssl"])
+        try:
+            run([str(python_bin), "-c", "import _ssl"])
+        except RuntimeError:
+            print(
+                "ERROR: Python was built without SSL support (_ssl module is missing). "
+                f"To fix this: remove the installed Python at {python_install}; "
+                "install OpenSSL development libraries and re-run."
+            )
+            raise
 
     if MAC_CROSS_COMPILE_INTEL:
         assert original_path
@@ -1515,7 +1519,7 @@ if "IfcOpenShell-Python" in targets:
         )
         # Copy setup.py where pyodide build system expects it.
         shutil.copy(REPO_PATH / "pyodide" / "setup.py", REPO_PATH)
-        # Empty pyproject so it's contents won't affect the resulting wheelthe the
+        # Empty pyproject so it's contents won't affect the resulting wheel
         # otherwise the wheel will use version and dependencies from toml, not setup.py.
         (REPO_PATH / "pyproject.toml").write_text("")
 

nix/cache_dependencies.py

@@ -1,3 +1,5 @@
+# /// script
+# ///
 """
 Cache built dependencies for builds.
 

pyodide/build_pyodide.sh

@@ -1,6 +1,11 @@
 #!/usr/bin/bash
 set -ex
 
+PYODIDE_VERSION=0.29.3
+PYODIDE_BUILD_VERSION=0.33.0
+PYODIDE_XBUILDENV_ROOT="${HOME}/.cache/.pyodide-xbuildenv-${PYODIDE_BUILD_VERSION}"
+PYODIDE_XBUILDENV="${PYODIDE_XBUILDENV_ROOT}/${PYODIDE_VERSION}"
+
 # Script is assuming that it will be possible to execute it multiple times
 # therefore we're clearing venv each time and ignoring existing 'emsdk' folder.
 
@@ -11,21 +16,15 @@ source .venv/bin/activate
 
 # Install pyodide cross build environment.
 # Instructions: https://pyodide.org/en/stable/development/building-packages.html
-uv pip install pyodide-build
+uv pip install "pyodide-build==${PYODIDE_BUILD_VERSION}"
 # `uv run` is required, so xbuildenv would skip using `pip`.
-uv run pyodide xbuildenv install
+uv run pyodide xbuildenv install "${PYODIDE_VERSION}"
+uv run pyodide xbuildenv install-emscripten
 
-# Emscripten doesn't come with xbuildenv.
-if [ ! -d emsdk ]; then
-  git clone https://github.com/emscripten-core/emsdk
-fi
-pushd emsdk
-PYODIDE_EMSCRIPTEN_VERSION=$(pyodide config get emscripten_version)
-./emsdk install ${PYODIDE_EMSCRIPTEN_VERSION}
-./emsdk activate ${PYODIDE_EMSCRIPTEN_VERSION}
-source emsdk_env.sh
+EMSDK_ROOT="${PYODIDE_XBUILDENV}/emsdk"
+source "${EMSDK_ROOT}/emsdk_env.sh"
 which emcc
-popd
+emcc --version
 
 mkdir -p packages/ifcopenshell
 VERSION=`cat IfcOpenShell/VERSION`

pyodide/pack_wheel.py

@@ -0,0 +1,232 @@
+#
+# /// script
+# # Latest Pyodide build env versions are listed here:
+# # https://pyodide.github.io/pyodide/api/pyodide-cross-build-environments.json
+# # https://github.com/pyodide/pyodide-build/blob/main/pyodide_build/xbuildenv_releases.py
+# requires-python = "==3.13.2"
+# dependencies = [
+#   "requests",
+#   "setuptools",
+# ]
+# ///
+"""
+Pack an IfcOpenShell WASM wheel using Pyodide build system.
+
+Usage:
+    uv run make_wheel.py           # Show this help
+    uv run make_wheel.py --build   # Build wheel
+    uv run make_wheel.py --clean   # Clean build artifacts and exit
+"""
+
+import argparse
+import os
+import re
+import shutil
+import subprocess
+import time
+import zipfile
+from pathlib import Path
+from urllib.parse import quote
+
+import requests
+
+# Get repo root (parent of this script's parent directory)
+REPO_ROOT = Path(__file__).parent.parent
+PYODIDE_DIR = REPO_ROOT / "pyodide"
+BUILD_DIR = PYODIDE_DIR / "build"
+
+# Hardcoded path (Windows packing workaround with --dev flag)
+PYODIDE_BUILD = Path(r"L:\Projects\Github\pyodide-build")
+
+# Wheel platform tag (from PYODIDE_EMSCRIPTEN_VERSION in pyodide-build/Makefile.envs)
+WHEEL_PLATFORM_TAG = "emscripten_4_0_9_wasm32"
+
+# Location where ifcopenshell will be extracted
+IFCOPENSHELL_DIR = PYODIDE_DIR / "ifcopenshell"
+
+
+class WheelBuilder:
+    @staticmethod
+    def extract_ifcopenshell_from_git(dst: Path) -> None:
+        """Extract ifcopenshell directory from git repo into destination."""
+        Tools.rmrf(dst)
+
+        print(f"Extracting ifcopenshell from git to {dst}...")
+        # Use git ls-files piped to git checkout-index to avoid copying
+        # untracked or ignored files from the actual repo.
+        ls_proc = subprocess.Popen(
+            ["git", "ls-files", "-z", "src/ifcopenshell-python/ifcopenshell"],
+            cwd=REPO_ROOT,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+        checkout_proc = subprocess.Popen(
+            ["git", "checkout-index", "-z", "--prefix", "pyodide/", "--stdin"],
+            cwd=REPO_ROOT,
+            stdin=ls_proc.stdout,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+        assert ls_proc.stdout is not None
+        ls_proc.stdout.close()
+        checkout_proc.communicate()
+
+        if checkout_proc.returncode != 0:
+            assert checkout_proc.stderr is not None
+            raise RuntimeError(f"Failed to extract: {checkout_proc.stderr.decode()}")
+
+        # Move src/ifcopenshell-python/ifcopenshell to ifcopenshell.
+        temp_src = PYODIDE_DIR / "src" / "ifcopenshell-python" / "ifcopenshell"
+        shutil.move(temp_src, dst)
+
+        # Clean up temporary src directory.
+        Tools.rmrf(PYODIDE_DIR / "src")
+
+        print("✓ Extracted ifcopenshell from git")
+
+    @staticmethod
+    def get_wheel_url(makefile_path: Path) -> str:
+        """Get S3 wheel URL based on BINARY_VERSION and BUILD_COMMIT from Makefile."""
+
+        def parse_makefile_vars() -> dict[str, str]:
+            content = makefile_path.read_text()
+            vars: dict[str, str] = {}
+            for match in re.finditer(r"^(BINARY_VERSION|BUILD_COMMIT):=(.+)$", content, re.MULTILINE):
+                vars[match.group(1)] = match.group(2).strip()
+            return vars
+
+        vars: dict[str, str] = parse_makefile_vars()
+        binary_version = vars["BINARY_VERSION"]
+        build_commit = vars["BUILD_COMMIT"]
+        filename = f"ifcopenshell-{binary_version}+{build_commit}-cp313-cp313-pyodide_2025_0_wasm32.whl"
+        encoded_filename = quote(filename, safe="")
+        return f"https://s3.amazonaws.com/ifcopenshell-builds/{encoded_filename}"
+
+    @staticmethod
+    def download_and_extract_so(url: str, build_dir: Path) -> tuple[Path, Path]:
+        """Download wheel from URL and extract .so and .py files."""
+        py_wrapper_filename = "ifcopenshell_wrapper.py"
+        build_dir.mkdir(parents=True, exist_ok=True)
+
+        wheel_path = build_dir / url.rsplit("/", 1)[-1]
+
+        if wheel_path.exists():
+            print(f"Using cached wheel: {wheel_path}")
+        else:
+            print(f"Downloading {url}...")
+            response = requests.get(url)
+            response.raise_for_status()
+            wheel_path.write_bytes(response.content)
+
+        print("Extracting _ifcopenshell_wrapper files...")
+        with zipfile.ZipFile(wheel_path) as zf:
+            so_files = [f for f in zf.namelist() if f.endswith(".so")]
+            py_files = [f for f in zf.namelist() if f.endswith(py_wrapper_filename)]
+
+            assert so_files, "No .so file found in wheel"
+            assert py_files, f"No {py_wrapper_filename} file found in wheel"
+
+            so_file = so_files[0]
+            so_dst = build_dir / Path(so_file).name
+            so_dst.write_bytes(zf.read(so_file))
+
+            py_file = py_files[0]
+            py_dst = build_dir / Path(py_file).name
+            py_dst.write_bytes(zf.read(py_file))
+
+        return so_dst, py_dst
+
+
+class Tools:
+    @staticmethod
+    def run(
+        cmd: list[str],
+        cwd: Path | None = None,
+    ) -> None:
+        print(f"$ {' '.join(cmd)}")
+        subprocess.check_call(cmd, cwd=cwd)
+
+    @staticmethod
+    def create_symlink(dst: Path, src: Path) -> None:
+        Tools.rmrf(dst)
+        dst.symlink_to(src)
+
+    @staticmethod
+    def rmrf(path: Path) -> None:
+        if path.exists() or path.is_symlink():
+            if path.is_dir() and not path.is_symlink():
+                shutil.rmtree(path)
+            else:
+                path.unlink()
+
+
+def clean() -> None:
+    """Remove build artifacts."""
+    paths_to_remove = (
+        BUILD_DIR,
+        PYODIDE_DIR / ".pyodide_build",
+        PYODIDE_DIR / "dist",
+        PYODIDE_DIR / "ifcopenshell.egg-info",
+        PYODIDE_DIR / "src",
+        IFCOPENSHELL_DIR,
+    )
+    for path in paths_to_remove:
+        if path.exists() or path.is_symlink():
+            print(f"Removing {path}...")
+            Tools.rmrf(path)
+    print("✓ Clean complete")
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description=__doc__, add_help=False)
+    parser.add_argument("--build", action="store_true", help="Build the wheel")
+    parser.add_argument("--clean", action="store_true", help="Clean build folder")
+    parser.add_argument(
+        "--dev",
+        action="store_true",
+        help="Use editable pyodide-build from hardcoded path (Windows packing workaround)",
+    )
+    args = parser.parse_args()
+
+    if not args.build and not args.clean:
+        print(__doc__)
+        return
+
+    if args.clean:
+        clean()
+        return
+
+    start_time = time.time()
+
+    WheelBuilder.extract_ifcopenshell_from_git(IFCOPENSHELL_DIR)
+
+    print("Downloading and extracting _ifcopenshell_wrapper files...")
+    makefile = REPO_ROOT / "src" / "ifcopenshell-python" / "Makefile"
+    wheel_url = WheelBuilder.get_wheel_url(makefile)
+    so_file, py_file = WheelBuilder.download_and_extract_so(wheel_url, BUILD_DIR)
+
+    Tools.create_symlink(IFCOPENSHELL_DIR / Path(so_file).name, so_file)
+    Tools.create_symlink(IFCOPENSHELL_DIR / Path(py_file).name, py_file)
+
+    print("Installing pyodide-build...")
+    if args.dev:
+        Tools.run(["uv", "pip", "install", "-e", str(PYODIDE_BUILD)])
+    else:
+        Tools.run(["uv", "pip", "install", "pyodide-build"])
+
+    print("Building with pyodide...")
+    # Use --no-isolation due to pyodide-build Windows support issues:
+    # symlink_unisolated_packages fails with missing `_sysconfigdata_$(CPYTHON_ABI_FLAGS)_emscripten_wasm32-emscripten.py`.
+    # Hardcode platform name since pyodide doesn't yet support overriding wheel tags on Windows.
+    #
+    # Use `LEGACY_PLATFORM` since pyodide 0.34.1 introduced new tag for wheels `pyemscripten`,
+    # which doesn't work with pyodide itself yet - https://github.com/pyodide/pyodide/issues/6177.
+    os.environ["USE_LEGACY_PLATFORM"] = "1"
+    Tools.run(["pyodide", "build", f"-C--build-option=--plat-name={WHEEL_PLATFORM_TAG}"])
+
+    elapsed = time.time() - start_time
+    print(f"\n✓ Done! ({elapsed:.1f}s)")
+
+
+if __name__ == "__main__":
+    main()

pyodide/setup.py

@@ -2,12 +2,16 @@
 # because `tool.setuptools.ext-modules` is still experimental in pyproject.toml
 # and we need it to get the wheel suffix right.
 import os
+import sys
 from pathlib import Path
 
 import tomllib
 from setuptools import Extension, find_packages, setup
+from setuptools.command.build_ext import build_ext
 
-REPO_FOLDER = Path(__file__).parent
+# Detect repo folder: if setup.py is in pyodide folder, go to parent
+SETUP_DIR = Path(__file__).parent
+REPO_FOLDER = SETUP_DIR.parent if SETUP_DIR.name == "pyodide" else SETUP_DIR
 
 
 def get_version() -> str:
@@ -25,6 +29,39 @@ def get_dependencies() -> list[str]:
     return dependencies
 
 
+class UnixBuildExt(build_ext):
+    """Customize ``build_ext`` to support packing on Windows."""
+
+    def finalize_options(self):
+        from distutils import sysconfig
+
+        super().finalize_options()
+        if sys.platform == "win32":
+            self.compiler = "unix"
+
+            # Configure sysconfig for Windows builds
+            # CCSHARED is the only variable that's not customizable with env vars.
+            # Basically avoiding this:
+            # File ".venv\Lib\site-packages\setuptools\_distutils\sysconfig.py", line 366, in customize_compiler
+            #     compiler_so=cc_cmd + ' ' + ccshared,
+            #                 ~~~~~~~~~~~~~^~~~~~~~~~
+            # TypeError: can only concatenate str (not "NoneType") to str
+            sysconfig.get_config_vars()  # Initialize config cache
+            if sysconfig._config_vars.get("CCSHARED") is None:
+                sysconfig._config_vars["CCSHARED"] = "-fPIC"
+            # Override compiler type before it's instantiated
+
+        # Set Emscripten compiler environment variables
+        os.environ["CC"] = "emcc"
+        os.environ["CXX"] = "em++"
+        os.environ["CFLAGS"] = ""
+        os.environ["CXXFLAGS"] = ""
+        os.environ["LDSHARED"] = "emcc -shared"
+        os.environ["AR"] = "emar"
+        os.environ["ARFLAGS"] = "rcs"
+        os.environ["SETUPTOOLS_EXT_SUFFIX"] = ".cpython-313-wasm32-emscripten.so"
+
+
 setup(
     name="ifcopenshell",
     version=get_version(),
@@ -44,4 +81,5 @@ setup(
     },
     # Has to provide extension to get the correct wheel suffix.
     ext_modules=[Extension("ifcopenshell._ifcopenshell_wrapper", sources=[])],
+    cmdclass={"build_ext": UnixBuildExt},
 )

pyproject.toml

@@ -3,8 +3,9 @@ name = "IfcOpenShell"
 version = "0.0.0"
 dependencies = [
     "black==26.3.1",
-    "ruff==0.15.8",
+    "ruff==0.15.12",
     "poethepoet",
+    "ty==0.0.32",
     "gersemi==0.26.1",
 ]
 
@@ -28,6 +29,9 @@ extend-exclude = '''
 reportInvalidTypeForm = false
 disableBytesTypePromotions = true
 reportUnnecessaryTypeIgnoreComment = true
+reportRedeclaration = false
+# Ignore warnings from bpy stubs missing actual source files.
+reportMissingModuleSource = false
 # Pylance doesn't respect gitignore, so we have to exclude files manually here
 # to avoid VS Code slowing down.
 # https://github.com/microsoft/pylance-release/issues/5169
@@ -84,7 +88,6 @@ all = "ignore"
 # Structural rules (no deep type inference needed, easier to adapt).
 abstract-method-in-final-class = "error"
 ambiguous-protocol-member = "error"
-byte-string-type-annotation = "error"
 conflicting-declarations = "error"
 conflicting-metaclass = "error"
 cyclic-class-definition = "error"
@@ -96,7 +99,6 @@ empty-body = "error"
 escape-character-in-forward-annotation = "error"
 final-on-non-method = "error"
 final-without-value = "error"
-fstring-type-annotation = "error"
 ignore-comment-unknown-rule = "error"
 implicit-concatenated-string-type-annotation = "error"
 inconsistent-mro = "error"
@@ -213,10 +215,7 @@ exclude = [
 
 [tool.poe.tasks]
 
-ruff-main = "ruff check --extend-exclude nix/build-all.py"
-# It's actually Python 3.6, but ruff only supports 3.7+, but it should do.
-ruff-old = "ruff check nix/build-all.py --target-version py37"
-ruff.sequence = ["ruff-main", "ruff-old"]
+ruff = "ruff check"
 
 black = "black ."
 
@@ -224,7 +223,7 @@ ty.sequence = ["ty-bonsai", "ty-ios"]
 ty.help = "Run ty type checker. Requires ty-venv to be set up first."
 ty-bonsai = "ty check src/bonsai --python=src/bonsai/.venv"
 
-ty-venv.sequence = ["ty-venv-bonsai", "ty-venv-ios"]
+ty-venv.sequence = ["bonsai-deps", "ty-venv-bonsai", "ty-venv-ios"]
 
 ty-venv-bonsai.sequence = [
     {cmd = "uv venv src/bonsai/.venv --python=3.11 --allow-existing"},
@@ -236,7 +235,7 @@ ty-venv-ios.sequence = [
     {cmd = "uv pip install -r src/ifcopenshell-python/type-check-requirements.txt --python=src/ifcopenshell-python/.venv"},
 ]
 
-format.sequence = ["black", "ruff-main", "ruff-old"]
+format.sequence = ["black", "ruff"]
 
 cmake-format = "gersemi . --in-place"
 

src/bonsai/Makefile

@@ -17,8 +17,8 @@
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
 
 SHELL := sh
-PYTHON:=python3.11
-PIP:=pip3.11
+PYTHON:=python3
+PIP:=pip3
 PATCH:=patch
 SED:=sed -i
 VENV_ACTIVATE:=bin/activate
@@ -64,7 +64,7 @@ PYNUMBER:=3$(PYMINOR)
 PYPI_VERSION:=3.$(PYMINOR)
 endif # def PYVERSION
 
-IFCMERGE_VERSION:=2026-04-02
+IFCMERGE_VERSION:=2026-04-07
 
 ifdef PLATFORM
 SUPPORTED_PLATFORMS := linux macos macosm1 win

src/bonsai/bonsai/bim/__init__.py

@@ -15,6 +15,8 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 import importlib
 import os
@@ -25,7 +27,19 @@ import bpy
 import bpy.utils.previews
 from bpy_extras.io_utils import ExportHelper, ImportHelper
 
-from . import handler, operator, prop, ui
+from . import handler, operator, parametric_lifecycle, prop, ui
+
+
+def _parametric_gizmo_preference_classes() -> list[type]:
+    """Resolves the registry-driven ``GizmoPreferences<X>`` classes for the
+    ``classes`` list below. ``import bonsai.tool`` is kept local to surface
+    the load-order constraint: it relies on ``from . import handler, …``
+    above having primed the
+    ``tool/ifc.py → bim/ifc.py → bim/handler.py → bonsai.tool`` cycle."""
+    import bonsai.tool as tool
+
+    return tool.Parametric.iter_gizmo_preference_classes(ui)
+
 
 try:
     from bonsai.translations import translations_dict
@@ -157,9 +171,10 @@ classes = [
     ui.BIM_UL_tab_visibilities,
     ui.BIM_UL_panel_visibilities,
     ui.DocPreferences,
-    ui.GizmoPreferencesDoor,  # Register before GizmoPreferences
-    ui.GizmoPreferencesWindow,  # Register before GizmoPreferences
-    ui.GizmoPreferencesStair,  # Register before GizmoPreferences
+    # Per-parametric-type ``GizmoPreferences<Name>`` classes — must register
+    # before ``ui.GizmoPreferences`` which holds the matching PointerProperty
+    # fields. Driven by ``tool.Parametric.EDIT_TYPES``.
+    *_parametric_gizmo_preference_classes(),
     ui.GizmoPreferences,
     # ui.DefaultParameters and ui.BIM_ADDON_preferences are registered separately after modules (see late_classes below)
     # Tabs panel
@@ -268,6 +283,8 @@ def register():
     bpy.app.handlers.depsgraph_update_post.append(on_register)
     bpy.app.handlers.undo_post.append(handler.undo_post)
     bpy.app.handlers.redo_post.append(handler.redo_post)
+    # Must follow the two appends above so regenerators see restored IFC state.
+    parametric_lifecycle.install_parametric_lifecycle_handlers()
     bpy.app.handlers.load_post.append(handler.load_post)
     bpy.app.handlers.load_post.append(handler.loadIfcStore)
     bpy.types.Scene.BIMProperties = bpy.props.PointerProperty(type=prop.BIMProperties)
@@ -325,6 +342,7 @@ def unregister():
 
     unregister_classes(classes)
 
+    parametric_lifecycle.uninstall_parametric_lifecycle_handlers()
     bpy.app.handlers.load_post.remove(handler.load_post)
     bpy.app.handlers.load_post.remove(handler.loadIfcStore)
     del bpy.types.Scene.BIMProperties

src/bonsai/bonsai/bim/data/fonts/LICENSE

@@ -0,0 +1,96 @@
+Copyright (c) 2011-2012, Nikita Volchenkov (<nikitavolchenkov@gmail.com>),
+with Reserved Font Name OpenGost Type B.
+
+Copyright (c) 2012, Valek Filippov (<frob@gnome.org>).
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded, 
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.

src/bonsai/bonsai/bim/decorator_cache.py

@@ -0,0 +1,119 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2026
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was generated with the assistance of an AI coding tool.
+
+"""Shared structural-change cache token for POST_VIEW decorators.
+
+Decorators include the token in their cache key and rebuild on bump."""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from typing import Any, Generic, TypeVar
+
+import bpy
+
+T = TypeVar("T")
+
+_DECORATOR_CACHE_TOKEN = 0
+
+
+def get_decorator_cache_token() -> int:
+    return _DECORATOR_CACHE_TOKEN
+
+
+def reset_for_test() -> None:
+    """Test-only: reset the cache token to 0 so bump-count assertions are stable."""
+    global _DECORATOR_CACHE_TOKEN
+    _DECORATOR_CACHE_TOKEN = 0
+
+
+@bpy.app.handlers.persistent
+def _bump_decorator_cache_token(*args: Any) -> None:
+    """depsgraph_update_post fires every animation frame and every driver
+    evaluation, even when no IFC-relevant ID block changed. Unconditional
+    bumping defeats the cache: an animated scene rebuilds every decorator
+    every viewport tick. Gate the depsgraph path on Object geometry or
+    transform updates; undo / redo / load have no depsgraph and always
+    invalidate.
+
+    Coverage assumption: ``TokenCache`` consumers key on Object identity
+    (depsgraph updates whose ``id`` is a ``bpy.types.Object``). Mesh /
+    Material / NodeTree updates that don't surface as an Object change
+    do NOT invalidate the token — a decorator that caches material- or
+    mesh-data-derived state must gate on a separate signal."""
+    global _DECORATOR_CACHE_TOKEN
+    if len(args) >= 2:
+        depsgraph = args[1]
+        if depsgraph is not None and hasattr(depsgraph, "updates"):
+            if not any(
+                (getattr(u, "is_updated_geometry", False) or getattr(u, "is_updated_transform", False))
+                and hasattr(u, "id")
+                and isinstance(u.id, bpy.types.Object)
+                for u in depsgraph.updates
+            ):
+                return
+    _DECORATOR_CACHE_TOKEN += 1
+
+
+def _hooks() -> tuple[Any, ...]:
+    return (
+        bpy.app.handlers.depsgraph_update_post,
+        bpy.app.handlers.undo_post,
+        bpy.app.handlers.redo_post,
+        bpy.app.handlers.load_post,
+    )
+
+
+def install_decorator_cache_handlers() -> None:
+    """Append the bump handler to each hook; idempotent."""
+    for hook in _hooks():
+        if _bump_decorator_cache_token not in hook:
+            hook.append(_bump_decorator_cache_token)
+
+
+def uninstall_decorator_cache_handlers() -> None:
+    for hook in _hooks():
+        try:
+            hook.remove(_bump_decorator_cache_token)
+        except ValueError:
+            pass
+
+
+class TokenCache(Generic[T]):
+    """Memoise a single value keyed on ``(caller_key, get_decorator_cache_token())``.
+
+    The token component invalidates the cache on depsgraph / undo / redo / load,
+    so cached ``bpy.types.Object`` references can't outlive the underlying ID
+    blocks. Holds exactly one entry — last key wins."""
+
+    __slots__ = ("_key", "_value")
+
+    def __init__(self) -> None:
+        self._key: tuple[Any, int] | None = None
+        self._value: T | None = None
+
+    def get_or_compute(self, key: Any, compute: Callable[[], T]) -> T:
+        token_key = (key, _DECORATOR_CACHE_TOKEN)
+        if token_key == self._key:
+            return self._value  # type: ignore[return-value]
+        value = compute()
+        self._key = token_key
+        self._value = value
+        return value

src/bonsai/bonsai/bim/handler.py

@@ -15,11 +15,12 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 import os
 import weakref
 from collections.abc import Callable
-from math import cos
 from typing import Union
 
 import bpy
@@ -31,8 +32,13 @@ from bpy.app.handlers import persistent
 from mathutils import Vector
 
 import bonsai.bim
+import bonsai.core.model as core_model
 import bonsai.tool as tool
-from bonsai.bim.ifc import IfcStore
+from bonsai.bim.decorator_cache import (
+    install_decorator_cache_handlers,
+    uninstall_decorator_cache_handlers,
+)
+from bonsai.bim.ifc import IfcStore, get_cache_or_detect_lock
 from bonsai.bim.module.aggregate.decorator import AggregateDecorator
 from bonsai.bim.module.georeference.decorator import GeoreferenceDecorator
 from bonsai.bim.module.model.data import AuthoringData
@@ -41,6 +47,7 @@ from bonsai.bim.module.model.decorator import (
     SlabDirectionDecorator,
     WallAxisDecorator,
 )
+from bonsai.bim.module.model.preview_base import discard_pending_previews
 from bonsai.bim.module.nest.decorator import NestDecorator
 
 cwd = os.path.dirname(os.path.realpath(__file__))
@@ -133,14 +140,32 @@ def update_bim_tool_props():
 
             if is_annotation_tool and (object_type := tool.Drawing.get_annotation_type_object_type(element_type)):
                 aprops.object_type = object_type
-                aprops.relating_type_id = str(element_type.id())
+                try:
+                    aprops.relating_type_id = str(element_type.id())
+                except TypeError:
+                    # EnumProperty items are rebuilt asynchronously when ifc_class changes;
+                    # this assignment can race a stale item list. Skipping is harmless —
+                    # the UI will resync on the next active_object_callback.
+                    pass
                 return
 
             if is_bim_tool:
                 props.ifc_class = element_type.is_a()
 
-            if is_bim_tool or TOOLS_TO_CLASSES_MAP.get(current_tool.idname) == element_type.is_a():
-                props.relating_type_id = str(element_type.id())
+            # Only assign when the target enum is the one that lists this type — otherwise
+            # we hit `enum "<id>" not found in (...)` if the user selects an element of a
+            # different class than the workspace tool was built for (e.g. selecting a wall
+            # while the door tool is active).
+            tool_class_match = TOOLS_TO_CLASSES_MAP.get(current_tool.idname) == element_type.is_a()
+            bim_tool_class_match = is_bim_tool and props.ifc_class == element_type.is_a()
+            if bim_tool_class_match or tool_class_match:
+                try:
+                    props.relating_type_id = str(element_type.id())
+                except TypeError:
+                    # Defensive: the enum item list can lag behind ifc_class assignment
+                    # above. Skipping leaves the panel briefly out of sync rather than
+                    # crashing the handler (which Blender re-fires on every selection).
+                    pass
 
     if is_annotation_tool:
         return
@@ -165,7 +190,9 @@ def update_bim_tool_props():
     if AuthoringData.data["active_material_usage"] == "LAYER2":
         x_angle = get_x_angle(extrusion)
         axis = tool.Model.get_wall_axis(obj)["reference"]
-        props.extrusion_depth = abs(extrusion.Depth * si_conversion * cos(x_angle))
+        props.extrusion_depth = core_model.vertical_height_from_extrusion_depth(
+            extrusion.Depth * si_conversion, x_angle
+        )
         props.length = (axis[1] - axis[0]).length
         props.x_angle = x_angle
 
@@ -356,8 +383,10 @@ def subscribe_to_viewport_shading_changes():
             )
 
 
-@persistent
-def load_post(scene):
+def _apply_save_file_invariants(scene: bpy.types.Scene) -> None:
+    """Invariants enforced on every load_post: msgbus subscription, IFC owner
+    settings, scene-bound caches, draft-flag healing, multi-instance lock probe,
+    and previews discarded so saved preview state never resurfaces on reopen."""
     global global_subscription_owner
     active_object_key = bpy.types.LayerObjects, "active"
     bpy.msgbus.subscribe_rna(
@@ -368,6 +397,24 @@ def load_post(scene):
     ifcopenshell.api.owner.settings.get_application = get_application
     AuthoringData.type_thumbnails = {}
 
+    tool.Parametric.heal_stale_edit_flags()
+    discard_pending_previews(scene)
+
+    if tool.Ifc.get() and bpy.data.is_saved:
+        props = tool.Blender.get_bim_props()
+        props.has_blend_warning = True
+
+    # Probe the H5 cooked-geometry cache so the multi-instance warning surfaces
+    # right after .blend load. Without this, the lock is only detected when a
+    # mutation triggers ``clear_cache`` — by which time the user has already
+    # made changes that may now conflict with the other Blender instance.
+    if tool.Ifc.get():
+        get_cache_or_detect_lock()
+
+
+def _apply_user_preferences() -> None:
+    """User-preference-driven UI setup: toolbar, BIM workspace, viewport shading
+    subscription, scene-panel hijack, tab layout, snap defaults."""
     preferences = tool.Blender.get_addon_preferences()
     if not preferences.should_setup_toolbar:
         tool.Blender.unregister_toolbar()
@@ -391,11 +438,21 @@ def load_post(scene):
         tool.Blender.override_scene_panel(panel)
     tool.Blender.setup_tabs()
 
-    if tool.Ifc.get() and bpy.data.is_saved:
-        props = tool.Blender.get_bim_props()
-        props.has_blend_warning = True
+    if preferences.should_use_snap and (scene := bpy.context.scene):
+        # Snapping is off by default in Blender, but in BIM, it's more useful to be on
+        scene.tool_settings.use_snap = True
+        # Match default Bonsai snaps
+        scene.tool_settings.snap_elements_base = {"EDGE", "EDGE_PERPENDICULAR", "VERTEX", "EDGE_MIDPOINT", "FACE"}
 
-    # Bonsai overlays
+    tool.Blender.sync_old_preferences()
+
+
+def _install_viewport_overlays() -> None:
+    """Sync every Bonsai viewport decorator to its enabled state.
+
+    Wrapped in uninstall/install of the decorator-cache bump handlers so a
+    decorator's own install path doesn't double-bind to depsgraph_update_post
+    via ``TokenCache`` instances created during their own ``install()``."""
     georeference_props = tool.Georeference.get_georeference_props()
     aggregate_props = tool.Aggregate.get_aggregate_props()
     nest_props = tool.Nest.get_nest_props()
@@ -405,23 +462,26 @@ def load_post(scene):
     NestDecorator.uninstall()
     WallAxisDecorator.uninstall()
     SlabDirectionDecorator.uninstall()
-    if georeference_props.should_visualise:
-        GeoreferenceDecorator.install(bpy.context)
-    if aggregate_props.aggregate_decorator:
-        AggregateDecorator.install(bpy.context)
-    if nest_props.nest_decorator:
-        NestDecorator.install(bpy.context)
-    if model_props.show_wall_axis:
-        WallAxisDecorator.install(bpy.context)
-    if model_props.show_slab_direction:
-        SlabDirectionDecorator.install(bpy.context)
-    if model_props.show_bounding_box:
-        BoundingBoxDecorator.install(bpy.context)
+    uninstall_decorator_cache_handlers()
+    try:
+        if georeference_props.should_visualise:
+            GeoreferenceDecorator.install(bpy.context)
+        if aggregate_props.aggregate_decorator:
+            AggregateDecorator.install(bpy.context)
+        if nest_props.nest_decorator:
+            NestDecorator.install(bpy.context)
+        if model_props.show_wall_axis:
+            WallAxisDecorator.install(bpy.context)
+        if model_props.show_slab_direction:
+            SlabDirectionDecorator.install(bpy.context)
+        if model_props.show_bounding_box:
+            BoundingBoxDecorator.install(bpy.context)
+    finally:
+        install_decorator_cache_handlers()
 
-    if preferences.should_use_snap and (scene := bpy.context.scene):
-        # Snapping is off by default in Blender, but in BIM, it's more useful to be on
-        scene.tool_settings.use_snap = True
-        # Match default Bonsai snaps
-        scene.tool_settings.snap_elements_base = {"EDGE", "EDGE_PERPENDICULAR", "VERTEX", "EDGE_MIDPOINT", "FACE"}
 
-    tool.Blender.sync_old_preferences()
+@persistent
+def load_post(scene):
+    _apply_save_file_invariants(scene)
+    _apply_user_preferences()
+    _install_viewport_overlays()

src/bonsai/bonsai/bim/ifc.py

@@ -64,6 +64,44 @@ class TransactionStep(TypedDict):
     operations: list[Operation]
 
 
+# Set when ``IfcStore.get_cache`` observes an external lock on the HDF5 cache —
+# signal that another Blender process has the same IFC file open. Project panel
+# polls ``is_cache_locked_by_other_process`` to warn the user. The dismissed
+# flag is sticky per-session so the warning doesn't re-nag once the user has
+# acknowledged it.
+_cache_locked_by_other_process: bool = False
+_multi_instance_warning_dismissed: bool = False
+
+
+def is_cache_locked_by_other_process() -> bool:
+    return _cache_locked_by_other_process and not _multi_instance_warning_dismissed
+
+
+def dismiss_multi_instance_warning() -> None:
+    global _multi_instance_warning_dismissed
+    _multi_instance_warning_dismissed = True
+
+
+def get_cache_or_detect_lock() -> ifcopenshell.geom.serializers.hdf5 | None:
+    """Like ``IfcStore.get_cache`` but tracks the multi-instance lock flag — sets
+    it on ``PermissionError``, clears it (along with the dismiss flag) when a
+    subsequent call succeeds. Returns ``None`` on lock; other exceptions
+    propagate. Callers that don't need the warning side effect can use
+    ``IfcStore.get_cache`` directly."""
+    global _cache_locked_by_other_process, _multi_instance_warning_dismissed
+    try:
+        cache = IfcStore.get_cache()
+    except PermissionError:
+        _cache_locked_by_other_process = True
+        return None
+    if _cache_locked_by_other_process:
+        # Lock released — clear both flags so a future re-locking re-surfaces
+        # the warning rather than staying suppressed by the previous dismiss.
+        _cache_locked_by_other_process = False
+        _multi_instance_warning_dismissed = False
+    return cache
+
+
 class IfcStore:
     path: str = ""
     """Should be set only using ``tool.Ifc.set_path``."""
@@ -196,7 +234,7 @@ class IfcStore:
                 shutil.copy2(IfcStore.cache_path, new_cache_path)
             except PermissionError:
                 pass  # Well we tried. No cache for you!
-        IfcStore.get_cache()
+        get_cache_or_detect_lock()
 
     @staticmethod
     def load_file(path: str) -> None:
@@ -514,6 +552,7 @@ class IfcStore:
                     BrickStore.end_transaction()
                 IfcStore.end_transaction(operator)
                 bonsai.bim.handler.refresh_ui_data()
+                tool.Parametric.refresh_post_commit()
 
                 if method == "MODAL":
                     cls.modal_in_progress = False

src/bonsai/bonsai/bim/module/aggregate/decorator.py

@@ -101,7 +101,7 @@ class AggregateDecorator:
         cls.is_installed = False
 
     def dotted_line_shader(self):
-        vert_out = gpu.types.GPUStageInterfaceInfo("my_interface")  # ty:ignore[too-many-positional-arguments]
+        vert_out = gpu.types.GPUStageInterfaceInfo("my_interface")
         vert_out.smooth("FLOAT", "v_ArcLength")
 
         shader_info = gpu.types.GPUShaderCreateInfo()

src/bonsai/bonsai/bim/module/aggregate/prop.py

@@ -73,6 +73,22 @@ def poll_related_object(self: "BIMObjectAggregateProperties", related_obj: bpy.t
     return True
 
 
+def update_relating_object(self, context):
+    if self.relating_object:
+        ifc_id = tool.Blender.get_object_bim_props(self.relating_object).ifc_definition_id
+        if ifc_id:
+            bpy.ops.bim.aggregate_assign_object(relating_object=ifc_id)
+            bpy.ops.bim.disable_editing_aggregate()
+
+
+def update_related_object(self, context):
+    if self.related_object:
+        ifc_id = tool.Blender.get_object_bim_props(self.related_object).ifc_definition_id
+        if ifc_id:
+            bpy.ops.bim.aggregate_assign_object(related_object=ifc_id)
+            bpy.ops.bim.disable_editing_aggregate()
+
+
 def update_aggregate_decorator(self, context):
     if self.aggregate_decorator:
         AggregateDecorator.install(bpy.context)
@@ -89,12 +105,15 @@ def update_aggregate_mode_decorator(self, context):
 
 class BIMObjectAggregateProperties(PropertyGroup):
     is_editing: BoolProperty(name="Is Editing")
-    relating_object: PointerProperty(name="Relating Whole", type=bpy.types.Object, poll=poll_relating_object)
+    relating_object: PointerProperty(
+        name="Relating Whole", type=bpy.types.Object, poll=poll_relating_object, update=update_relating_object
+    )
     related_object: PointerProperty(
         name="Related Part",
         description="Related Part, will be used to derive the Relating Object",
         type=bpy.types.Object,
         poll=poll_related_object,
+        update=update_related_object,
     )
 
     if TYPE_CHECKING:

src/bonsai/bonsai/bim/module/attribute/operator.py

@@ -295,13 +295,13 @@ class ExplorerShowUIPopup(bpy.types.Operator):
     bl_description = "Show Explorer UI to select element as attribute value or edit it."
     bl_options = {"REGISTER", "UNDO"}
 
-    ifc_class: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    ifc_class: bpy.props.StringProperty()
     """Element IFC class."""
-    attribute_name: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    attribute_name: bpy.props.StringProperty()
     """IFC class attribute name."""
-    data_path: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    data_path: bpy.props.StringProperty()
     """Full data path"""
-    preselect_ifc_id: bpy.props.IntProperty(options={"SKIP_SAVE"})  # pyright: ignore[reportRedeclaration]
+    preselect_ifc_id: bpy.props.IntProperty(options={"SKIP_SAVE"})
     """IFC id to preselect in the popup."""
 
     if TYPE_CHECKING:

src/bonsai/bonsai/bim/module/attribute/prop.py

@@ -41,7 +41,7 @@ class BIMAttributeProperties(PropertyGroup):
 
 
 class ExplorerEntity(PropertyGroup):
-    ifc_definition_id: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    ifc_definition_id: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         ifc_definition_id: int
@@ -60,7 +60,7 @@ class BIMExplorerProperties(PropertyGroup):
             self.property_unset("editing_entity_id")
             self.entity_attributes.clear()
 
-    is_loaded: BoolProperty(  # pyright: ignore[reportRedeclaration]
+    is_loaded: BoolProperty(
         name="Toggle Explorer UI",
         update=update_is_loaded,
     )
@@ -76,15 +76,15 @@ class BIMExplorerProperties(PropertyGroup):
     def update_ifc_class(self, context: object) -> None:
         tool.Attribute.refresh_uilist_entities()
 
-    ifc_class: EnumProperty(  # pyright: ignore[reportRedeclaration]
+    ifc_class: EnumProperty(
         name="IFC Class To Search",
         items=get_ifc_class,
         update=update_ifc_class,
     )
-    entities: CollectionProperty(type=ExplorerEntity)  # pyright: ignore[reportRedeclaration]
-    active_entity_index: IntProperty()  # pyright: ignore[reportRedeclaration]
-    editing_entity_id: IntProperty()  # pyright: ignore[reportRedeclaration]
-    entity_attributes: CollectionProperty(type=Attribute)  # pyright: ignore[reportRedeclaration]
+    entities: CollectionProperty(type=ExplorerEntity)
+    active_entity_index: IntProperty()
+    editing_entity_id: IntProperty()
+    entity_attributes: CollectionProperty(type=Attribute)
 
     if TYPE_CHECKING:
         is_loaded: bool

src/bonsai/bonsai/bim/module/clash/operator.py

@@ -201,16 +201,10 @@ class ExecuteIfcClash(bpy.types.Operator, ExportHelper):
         "ALT+click to run a quick clash without selecting a file to save."
     )
 
-    filter_glob: bpy.props.StringProperty(  # pyright: ignore[reportRedeclaration]
-        default="*.bcf;*.json", options={"HIDDEN"}
-    )
-    format: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
-        name="Format", items=[(i, i, "") for i in ("bcf", "json")]
-    )
-    filepath: bpy.props.StringProperty(  # pyright: ignore[reportRedeclaration]
-        subtype="FILE_PATH", options={"SKIP_SAVE"}
-    )
-    quick_clash: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    filter_glob: bpy.props.StringProperty(default="*.bcf;*.json", options={"HIDDEN"})
+    format: bpy.props.EnumProperty(name="Format", items=[(i, i, "") for i in ("bcf", "json")])
+    filepath: bpy.props.StringProperty(subtype="FILE_PATH", options={"SKIP_SAVE"})
+    quick_clash: bpy.props.BoolProperty(
         options={"SKIP_SAVE"},
     )
 

src/bonsai/bonsai/bim/module/clash/prop.py

@@ -37,12 +37,12 @@ from bonsai.bim.prop import BIMFilterGroup, StrProperty
 
 
 class ClashSource(PropertyGroup):
-    name: StringProperty(  # pyright: ignore[reportRedeclaration]
+    name: StringProperty(
         name="File",
         description="Absolute filepath to existing .ifc file to use as a clash source.",
     )
-    filter_groups: CollectionProperty(type=BIMFilterGroup, name="Filter Groups")  # pyright: ignore[reportRedeclaration]
-    mode: EnumProperty(  # pyright: ignore[reportRedeclaration]
+    filter_groups: CollectionProperty(type=BIMFilterGroup, name="Filter Groups")
+    mode: EnumProperty(
         items=[
             ("a", "All Elements", "All elements will be used for clashing"),
             ("i", "Include", "Only the selected elements are included for clashing"),
@@ -62,7 +62,7 @@ class Clash(PropertyGroup):
     b_global_id: StringProperty(name="B")
     a_name: StringProperty(name="A Name")
     b_name: StringProperty(name="B Name")
-    clash_type: EnumProperty(  # pyright: ignore[reportRedeclaration]
+    clash_type: EnumProperty(
         name="Clash Type",
         items=tuple((i, i, "") for i in CLASH_TYPE_ITEMS),
     )

src/bonsai/bonsai/bim/module/cost/operator.py

@@ -87,7 +87,7 @@ class CopyCostSchedule(bpy.types.Operator, tool.Ifc.Operator):
     bl_label = "Copy Cost Schedule"
     bl_description = "Create a duplicate of the provided cost schedule."
     bl_options = {"REGISTER", "UNDO"}
-    cost_schedule: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    cost_schedule: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         cost_schedule: int

src/bonsai/bonsai/bim/module/debug/operator.py

@@ -260,14 +260,14 @@ class CreateAllShapes(bpy.types.Operator):
     )
     bl_options = {"REGISTER"}
 
-    geometry_library: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    geometry_library: bpy.props.EnumProperty(
         name="Geometry Library",
         description="Geometry library to use for testing shape creation.",
         items=[(i, i, "") for i in get_args(ifcopenshell.geom.GEOMETRY_LIBRARY)],
         # By default use the same library as used for importing ifc project.
         default="hybrid-cgal-simple-opencascade",
     )
-    custom_geometry_library: bpy.props.StringProperty(  # pyright: ignore[reportRedeclaration]
+    custom_geometry_library: bpy.props.StringProperty(
         name="Custom Geometry Library",
         description="Provide a custom geometry library name, will override the 'geometry library' property.",
     )
@@ -781,7 +781,7 @@ class PurgeUnusedObjects(bpy.types.Operator, tool.Ifc.Operator):
     bl_label = "Purge Unused Objects"
     bl_options = {"REGISTER", "UNDO"}
 
-    object_type: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    object_type: bpy.props.EnumProperty(
         name="Object Type",
         items=((s, s.capitalize(), "") for s in get_args(tool.Debug.PurgeMergeObjectType)),
     )
@@ -827,7 +827,7 @@ class MergeIdenticalObjects(bpy.types.Operator, tool.Ifc.Operator):
     )
     bl_options = {"REGISTER", "UNDO"}
 
-    object_type: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    object_type: bpy.props.EnumProperty(
         name="Object Type",
         items=((s, s.capitalize(), "") for s in get_args(tool.Debug.PurgeMergeObjectType)),
     )
@@ -1073,7 +1073,7 @@ class ChangeLogLevel(bpy.types.Operator):
     bl_options = {"REGISTER"}
     bl_description = "Change general log level across all Python code in Blender"
 
-    log_level: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    log_level: bpy.props.EnumProperty(
         name="Log Level",
         items=[(i, i, "") for i in get_args(LogLevelType)],
         default="WARNING",

src/bonsai/bonsai/bim/module/drawing/__init__.py

@@ -15,6 +15,8 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 import bpy
 
@@ -143,6 +145,14 @@ classes = (
     gizmos.GizmoCancel,
     gizmos.GizmoPlus,
     gizmos.GizmoMinus,
+    gizmos.GizmoMerge,
+    gizmos.GizmoSplit,
+    gizmos.GizmoExtend,
+    gizmos.GizmoExtendVertical,
+    gizmos.GizmoOffsetExterior,
+    gizmos.GizmoOffsetCenter,
+    gizmos.GizmoOffsetInterior,
+    gizmos.GizmoAddOpening,
     gizmos.GizmoCycle,
     # Drawing-specific gizmos
     gizmos.UglyDotGizmo,

src/bonsai/bonsai/bim/module/drawing/gizmos.py

@@ -16,6 +16,8 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 """
 Gizmo infrastructure for parametric BIM element editing.
@@ -511,6 +513,7 @@ class DimensionTextRenderer:
         color: tuple[float, float, float],
         offset_sign: int = 1,
         alignment: TextAlignment | str = TextAlignment.CENTER,
+        display_text: str | None = None,
     ) -> None:
         """Draw formatted dimension value text at the given screen position.
 
@@ -522,15 +525,20 @@ class DimensionTextRenderer:
             color: Text color (r, g, b)
             offset_sign: 1 for above/right, -1 for below/left
             alignment: TextAlignment enum value
+            display_text: Pre-formatted label. If provided, used verbatim instead of
+                formatting `value`.
         """
         # Normalize string to enum for comparison
         if isinstance(alignment, str):
             alignment = TextAlignment(alignment)
 
-        is_negative = value < 0
-        text = tool.Unit.format_distance(abs(value))
-        if is_negative:
-            text = "-" + text
+        if display_text is not None:
+            text = display_text
+        else:
+            is_negative = value < 0
+            text = tool.Unit.format_distance(abs(value))
+            if is_negative:
+                text = "-" + text
 
         font_id = 0
         font_size = tool.Blender.scale_font_size(self.VALUE_FONT_SIZE)
@@ -795,6 +803,7 @@ class DimensionRenderer:
         text_alignment: TextAlignment = TextAlignment.CENTER,
         prop_name: str | None = None,
         display_value: float | None = None,
+        display_text: str | None = None,
     ) -> None:
         """Draw complete dimension graphics in screen space.
 
@@ -816,6 +825,8 @@ class DimensionRenderer:
             text_alignment: TextAlignment enum for text positioning
             prop_name: Property name for tooltip (shown when highlighted)
             display_value: Value to display as text (can be negative); uses dimension_length if None
+            display_text: Pre-formatted label string. If provided, used verbatim instead of
+                formatting `display_value` via tool.Unit.format_distance.
         """
         if dimension_length < 0:
             return
@@ -935,7 +946,14 @@ class DimensionRenderer:
                 )
                 text_color = highlight_color if is_highlight else color
                 DimensionTextRenderer.get_instance().draw_value_text(
-                    context, center_screen, perpendicular, text_value, text_color, text_offset_sign, text_alignment
+                    context,
+                    center_screen,
+                    perpendicular,
+                    text_value,
+                    text_color,
+                    text_offset_sign,
+                    text_alignment,
+                    display_text,
                 )
 
             if is_highlight and prop_name:
@@ -1121,6 +1139,13 @@ class DimensionGizmoConfig:
             If provided, eliminates need for get_dimension_matrix_{attr_name} method.
             The returned Vector is the local-space position where the gizmo origin
             will be placed. Combined with axis to create the full transformation matrix.
+        text_formatter: Optional function(props, value) -> str for the dimension label.
+            Receives the props bag and the post-`compute_value` display value
+            (i.e. the same number `apply_value` consumes during drag — for the
+            wall slope gizmo this is the displacement, NOT the underlying
+            `x_angle`). The raw underlying attribute is accessible as
+            `getattr(props, attr_name)`. If None, falls back to the default
+            `tool.Unit.format_distance(abs(value))` with negative-sign handling.
     """
 
     attr_name: str
@@ -1138,6 +1163,7 @@ class DimensionGizmoConfig:
     apply_value: Callable[[Any, float], None] | None = None
     visibility_condition: Callable[[Any], bool] | None = None
     matrix_position: Callable[[Any], "Vector"] | None = None  # Optional: function(props) -> Vector position
+    text_formatter: Callable[[Any, float], str] | None = None  # Optional: function(props, value) -> label text
 
     def __post_init__(self):
         # Validate attr_name
@@ -1576,6 +1602,78 @@ def get_billboard_rotation(context: bpy.types.Context) -> Matrix:
     return rv3d.view_matrix.to_3x3().transposed().to_4x4()
 
 
+def billboarded_at(world_pos: Vector, billboard_rot: Matrix, scale: float = 0.5) -> Matrix:
+    """Compose the standard icon ``matrix_basis``: translate to ``world_pos``, billboard
+    to the camera, then uniformly scale. Replaces the repeated
+    ``Matrix.Translation(...) @ billboard_rot @ Matrix.Scale(scale, 4)`` pattern."""
+    return Matrix.Translation(world_pos) @ billboard_rot @ Matrix.Scale(scale, 4)
+
+
+def setup_icon_gizmo(
+    gizmo_group: bpy.types.GizmoGroup,
+    gizmo_type: str,
+    color: tuple[float, float, float],
+    highlight_color: tuple[float, float, float],
+    operator: str,
+    alpha: float = 0.8,
+) -> bpy.types.Gizmo:
+    """Create and configure a stand-alone icon gizmo with the Bonsai defaults
+    (no draw-scale, fixed alpha, click-to-operator). Use this from any
+    ``GizmoGroup.setup`` to avoid hand-rolling the same five property assignments."""
+    gizmo = gizmo_group.gizmos.new(gizmo_type)
+    gizmo.use_draw_scale = False
+    gizmo.color = color
+    gizmo.color_highlight = highlight_color
+    gizmo.alpha = alpha
+    gizmo.target_set_operator(operator)
+    return gizmo
+
+
+# --- Tris geometry helpers ----------------------------------------------------
+# Shared by the icon ``bpy.types.Gizmo`` subclasses defined later in this module.
+# Each gizmo declares a flat ``tris`` tuple of (x, y, z) vertices grouped into
+# triangles of 3; these helpers compose tris from primitives so the per-gizmo
+# definitions stay small and visually readable.
+
+
+def rect_tris(x0: float, y0: float, x1: float, y1: float) -> tuple[tuple[float, float, float], ...]:
+    """Two triangles forming an axis-aligned rectangle from ``(x0, y0)`` to ``(x1, y1)``,
+    in the Z=0 plane (the convention for icon gizmos)."""
+    return (
+        (x0, y0, 0.0),
+        (x0, y1, 0.0),
+        (x1, y1, 0.0),
+        (x0, y0, 0.0),
+        (x1, y1, 0.0),
+        (x1, y0, 0.0),
+    )
+
+
+def swap_xy_tris(
+    tris: tuple[tuple[float, float, float], ...],
+) -> tuple[tuple[float, float, float], ...]:
+    """Reflect a ``tris`` tuple across the Y=X diagonal — useful when a "vertical"
+    sibling of a "horizontal" icon should otherwise be a literal copy."""
+    return tuple((y, x, z) for x, y, z in tris)
+
+
+class TrisGizmoMixin:
+    """Mixin for stand-alone ``bpy.types.Gizmo`` classes whose only behaviour is
+    drawing a static ``tris`` triangle tuple. Subclasses set the class-level
+    ``tris`` and ``bl_idname`` attributes; the mixin supplies ``setup`` / ``draw`` /
+    ``draw_select``. Use only with gizmos that have no per-instance state beyond
+    ``custom_shape``."""
+
+    def setup(self) -> None:
+        self.custom_shape = self.new_custom_shape("TRIS", self.tris)
+
+    def draw(self, context: bpy.types.Context) -> None:
+        self.draw_custom_shape(self.custom_shape)
+
+    def draw_select(self, context: bpy.types.Context, select_id: int) -> None:
+        self.draw_custom_shape(self.custom_shape, select_id=select_id)
+
+
 def get_camera_direction(context: bpy.types.Context, position: Vector) -> Vector | None:
     """Get normalized direction from position towards camera."""
     rv3d = context.region_data
@@ -3042,6 +3140,145 @@ class GizmoMinus(bpy.types.Gizmo):
         self.draw_custom_shape(self.custom_shape, select_id=select_id)
 
 
+class GizmoMerge(TrisGizmoMixin, bpy.types.Gizmo):
+    """Two arrows pointing inward toward each other — conveys joining/merging elements."""
+
+    bl_idname = "VIEW3D_GT_merge"
+
+    __slots__ = ("custom_shape",)
+
+    # Two solid triangles pointing toward the center on the horizontal axis,
+    # plus two thin tails behind each tip to make them read as arrows rather than
+    # standalone triangles.
+    tris = (
+        # Left arrowhead pointing right (tip at x≈-0.05).
+        (-0.35, -0.20, 0.0),
+        (-0.35, 0.20, 0.0),
+        (-0.05, 0.0, 0.0),
+        # Left tail behind the arrowhead.
+        *rect_tris(-0.45, -0.06, -0.30, 0.06),
+        # Right arrowhead pointing left (tip at x≈0.05).
+        (0.35, -0.20, 0.0),
+        (0.35, 0.20, 0.0),
+        (0.05, 0.0, 0.0),
+        # Right tail behind the arrowhead.
+        *rect_tris(0.30, -0.06, 0.45, 0.06),
+    )
+
+
+class GizmoSplit(TrisGizmoMixin, bpy.types.Gizmo):
+    """Two arrows pointing outward away from each other — conveys splitting/cutting
+    one element into two. Visual inverse of `GizmoMerge`."""
+
+    bl_idname = "VIEW3D_GT_split"
+
+    __slots__ = ("custom_shape",)
+
+    # Two solid triangles pointing OUTWARD on the horizontal axis (tips at x=±0.35),
+    # with tails extending toward the centerline. The tails meet at center to form a
+    # short horizontal bar, suggesting the split point itself.
+    tris = (
+        # Left arrowhead pointing left (tip at x=-0.35).
+        (-0.05, -0.20, 0.0),
+        (-0.05, 0.20, 0.0),
+        (-0.35, 0.0, 0.0),
+        # Left tail extending toward the right (away from the tip, toward center).
+        *rect_tris(-0.05, -0.06, 0.10, 0.06),
+        # Right arrowhead pointing right (tip at x=0.35).
+        (0.05, -0.20, 0.0),
+        (0.05, 0.20, 0.0),
+        (0.35, 0.0, 0.0),
+        # Right tail extending toward the left.
+        *rect_tris(-0.10, -0.06, 0.05, 0.06),
+    )
+
+
+class GizmoExtend(TrisGizmoMixin, bpy.types.Gizmo):
+    """An arrow pointing into a vertical bar — conveys extending an element to a target
+    line (e.g. extending a wall to the 3D cursor)."""
+
+    bl_idname = "VIEW3D_GT_extend"
+
+    __slots__ = ("custom_shape",)
+
+    # Layout: thick vertical bar at the right edge (the "target") with a horizontal
+    # arrow pointing into it from the left.
+    tris = (
+        # Vertical target bar (x = 0.25 to 0.35, full height).
+        *rect_tris(0.25, -0.30, 0.35, 0.30),
+        # Arrowhead pointing right toward the bar (tip at x=0.20).
+        (-0.05, -0.18, 0.0),
+        (-0.05, 0.18, 0.0),
+        (0.20, 0.0, 0.0),
+        # Tail extending leftward from the arrowhead base.
+        *rect_tris(-0.35, -0.06, -0.05, 0.06),
+    )
+
+
+class GizmoExtendVertical(TrisGizmoMixin, bpy.types.Gizmo):
+    """Vertical sibling of `GizmoExtend` — arrow pointing UP into a horizontal
+    bar. Conveys extending an element's height to a target Z."""
+
+    bl_idname = "VIEW3D_GT_extend_vertical"
+
+    __slots__ = ("custom_shape",)
+
+    # Mechanically derived from GizmoExtend by reflecting across Y=X.
+    tris = swap_xy_tris(GizmoExtend.tris)
+
+
+def _offset_baseline_tris(mark_x: float) -> tuple[tuple[float, float, float], ...]:
+    """Shared geometry for the three offset-baseline icons: a horizontal "wall
+    section" bar with a vertical mark at ``mark_x`` indicating where the reference
+    axis sits within the wall thickness. Matches the visual convention used in the
+    Bonsai N-panel's wall Align row."""
+    return rect_tris(-0.25, -0.07, 0.25, 0.07) + rect_tris(mark_x - 0.04, -0.22, mark_x + 0.04, 0.22)
+
+
+class GizmoOffsetExterior(TrisGizmoMixin, bpy.types.Gizmo):
+    """Wall offset baseline indicator — reference axis at the exterior face (left mark)."""
+
+    bl_idname = "VIEW3D_GT_offset_exterior"
+    __slots__ = ("custom_shape",)
+    tris = _offset_baseline_tris(-0.24)
+
+
+class GizmoOffsetCenter(TrisGizmoMixin, bpy.types.Gizmo):
+    """Wall offset baseline indicator — reference axis at the centreline (middle mark)."""
+
+    bl_idname = "VIEW3D_GT_offset_center"
+    __slots__ = ("custom_shape",)
+    tris = _offset_baseline_tris(0.0)
+
+
+class GizmoOffsetInterior(TrisGizmoMixin, bpy.types.Gizmo):
+    """Wall offset baseline indicator — reference axis at the interior face (right mark)."""
+
+    bl_idname = "VIEW3D_GT_offset_interior"
+    __slots__ = ("custom_shape",)
+    tris = _offset_baseline_tris(0.24)
+
+
+class GizmoAddOpening(TrisGizmoMixin, bpy.types.Gizmo):
+    """A rectangular frame (square outline with a hole in the middle) — conveys adding an
+    opening (window/door/void) to a wall."""
+
+    bl_idname = "VIEW3D_GT_add_opening"
+
+    __slots__ = ("custom_shape",)
+
+    # Outer 0.40 × 0.40 square with a 0.25 × 0.25 inner hole, drawn as four bars
+    # forming a frame, plus a small "+" in the inner hole to convey "add".
+    tris = (
+        *rect_tris(-0.20, 0.125, 0.20, 0.20),  # Top bar
+        *rect_tris(-0.20, -0.20, 0.20, -0.125),  # Bottom bar
+        *rect_tris(-0.20, -0.125, -0.125, 0.125),  # Left bar
+        *rect_tris(0.125, -0.125, 0.20, 0.125),  # Right bar
+        *rect_tris(-0.07, -0.015, 0.07, 0.015),  # "+" horizontal stroke
+        *rect_tris(-0.015, -0.07, 0.015, 0.07),  # "+" vertical stroke
+    )
+
+
 def _generate_circular_arrow_tris() -> tuple[tuple[float, float, float], ...]:
     """Generate circular arrow geometry covering ~300 degrees."""
     triangles = []
@@ -3421,6 +3658,7 @@ class GizmoDimension(GizmoMovable):
         "_original_value",  # Original property value before interaction
         "_click_offset",  # Offset from dimension tip to click position (for snap correction)
         "show_extension_lines",  # Whether to show extension lines at dimension endpoints
+        "text_formatter",  # Optional (props, value) -> str to override the default dimension label
     )
 
     ARROW_SIZE = 10
@@ -3479,6 +3717,16 @@ class GizmoDimension(GizmoMovable):
         start_world = self.matrix_basis.translation.copy()
         end_world = start_world + axis_world * self._dimension_length
 
+        display_value = getattr(self, "_display_value", self._dimension_length)
+        text_formatter = getattr(self, "text_formatter", None)
+        gizmo_group = getattr(self, "gizmo_group", None)
+        display_text: str | None = None
+        if text_formatter is not None and gizmo_group is not None:
+            obj = bpy.context.active_object
+            props = gizmo_group.get_props(obj) if obj is not None else None
+            if props is not None:
+                display_text = text_formatter(props, display_value)
+
         DimensionRenderer.get_instance().draw(
             context=context,
             start_world=start_world,
@@ -3496,7 +3744,8 @@ class GizmoDimension(GizmoMovable):
             text_offset_sign=getattr(self, "text_offset_sign", 1),
             text_alignment=getattr(self, "text_alignment", TextAlignment.CENTER),
             prop_name=getattr(self, "prop_name", None),
-            display_value=getattr(self, "_display_value", self._dimension_length),
+            display_value=display_value,
+            display_text=display_text,
         )
 
     def _calculate_screen_endpoints(self, context: bpy.types.Context) -> tuple[Vector, Vector, Vector, float] | None:
@@ -3615,6 +3864,11 @@ class GizmoDimension(GizmoMovable):
         self._display_value = max(-10000.0, min(length, 10000.0))
         # Clamp to valid range (0 to 10000 meters is reasonable for BIM) for drawing
         self._dimension_length = max(0.0, min(abs(length), 10000.0))
+        # Smaller dimensions win selection when hit regions overlap: a long gizmo's
+        # hit box fully contains a nested short one's, so without a bias the long
+        # one wins and the short one is unreachable. The long one stays clickable
+        # at its exposed ends regardless of bias.
+        self.select_bias = -self._dimension_length
 
     def invoke(self, context: bpy.types.Context, event: bpy.types.Event) -> set:
         """Initialize dimension gizmo interaction with click-position tracking.
@@ -3913,6 +4167,59 @@ class CycleTypeMixin:
         return {"FINISHED"}
 
 
+class BillboardingGizmoGroupMixin:
+    """Mixin for standalone ``bpy.types.GizmoGroup`` classes whose icons must billboard
+    (face the camera) and re-position every frame.
+
+    Blender calls ``GizmoGroup.refresh()`` only on state-change events (selection,
+    property change, dependency update) — not on camera rotation. A gizmo group that
+    only sets ``matrix_basis`` in ``refresh()`` will appear to "freeze" its rotation
+    at the camera angle in effect when it was last refreshed; orbiting the camera
+    leaves the icon facing the wrong way.
+
+    ``draw_prepare()`` *is* called every redraw, so the fix is to run the same
+    positioning code from both events. Rather than overriding ``refresh()`` and
+    ``draw_prepare()`` in every gizmo group that has this need, subclass this mixin
+    and implement a single ``position_gizmos(context)`` method.
+
+    Usage::
+
+        class MyGizmoGroup(bpy.types.GizmoGroup, BillboardingGizmoGroupMixin):
+            bl_idname = "..."
+            ...
+            def setup(self, context):
+                ...
+            def position_gizmos(self, context):
+                # set matrix_basis on every gizmo here, using get_billboard_rotation
+                # for any icon that should face the camera.
+                ...
+
+    ``position_gizmos`` should be idempotent — it's called twice when a state change
+    coincides with a redraw (once via ``refresh``, once via ``draw_prepare``)."""
+
+    def refresh(self, context: bpy.types.Context) -> None:
+        self.position_gizmos(context)
+
+    def draw_prepare(self, context: bpy.types.Context) -> None:
+        self.position_gizmos(context)
+
+    def setup_icon_gizmo(
+        self,
+        gizmo_type: str,
+        color: tuple[float, float, float],
+        highlight_color: tuple[float, float, float],
+        operator: str,
+        alpha: float = 0.8,
+    ) -> bpy.types.Gizmo:
+        """Convenience wrapper over `setup_icon_gizmo` for subclasses."""
+        return setup_icon_gizmo(self, gizmo_type, color, highlight_color, operator, alpha)
+
+    def position_gizmos(self, context: bpy.types.Context) -> None:
+        raise NotImplementedError(
+            f"{type(self).__name__} must implement position_gizmos(context) when using BillboardingGizmoGroupMixin."
+        )
+
+
 class BaseParametricGizmoGroup:
     """Base mixin for parametric element gizmo groups (doors, windows, stairs, etc.).
 
@@ -4129,6 +4436,32 @@ class BaseParametricGizmoGroup:
             return width + (self.GIZMO_OFFSET if use_offset else 0)
         return -self.GIZMO_OFFSET if use_offset else 0
 
+    @staticmethod
+    def get_camera_facing_outer_y(
+        viewing_from_negative_y: bool,
+        near_y: float,
+        far_y: float,
+        gizmo_offset: float = 0.0,
+    ) -> float:
+        """Y coordinate just outside the camera-facing face of an element.
+
+        Generalises `get_y_position_for_view` for elements whose near face
+        isn't at the local origin. ``near_y`` is the local-Y of the -Y face;
+        ``far_y`` is the local-Y of the +Y face. Returns the Y just *outside* the
+        face the camera is currently looking at, pushed by ``gizmo_offset`` (use
+        ``cls.GIZMO_OFFSET`` for the standard handle gap).
+
+        Suits walls (``near_y = props.offset``, ``far_y = props.offset + props.thickness``)
+        and any other element whose section sits inside a non-zero Y band. Stair /
+        door / window can also call this once their callers pass explicit near/far
+        instead of the implicit ``width_attr`` pattern, eliminating
+        ``get_y_position_for_view``, ``get_lining_y_position_for_view`` etc. as
+        wrappers around the same shape — but they're left intact for now to avoid
+        churning code paths that already work."""
+        if viewing_from_negative_y:
+            return near_y - gizmo_offset
+        return far_y + gizmo_offset
+
     def get_icon_y_for_view(self, props, viewing_from_negative_y: bool) -> float:
         """Get Y position for editing icons based on view direction.
 
@@ -4224,13 +4557,13 @@ class BaseParametricGizmoGroup:
         """
         return 0.0
 
-    def _update_view_dependent_dimensions(self, context: bpy.types.Context, mw: Matrix, props) -> None:
+    def _update_view_dependent_dimensions(self, context: bpy.types.Context, mw: Matrix, props) -> None:  # noqa: ARG002
         """Update overall_width, overall_height, and lining_offset based on view direction.
 
         This base implementation handles the common pattern for door/window gizmos.
         Subclasses can override get_casing_offset() to customize behavior.
         """
-        viewing_from_negative_y, viewing_from_negative_x = self.get_local_view_direction(context, mw)
+        viewing_from_negative_y, viewing_from_negative_x = self._frame_view_dir
         y_pos = self.get_lining_y_position_for_view(props, viewing_from_negative_y)
 
         self.set_dimension_gizmo_position("overall_width", mw, Vector((0, y_pos, -self.GIZMO_OFFSET)), (1, 0, 0))
@@ -4309,21 +4642,15 @@ class BaseParametricGizmoGroup:
 
     @classmethod
     def poll(cls, context) -> bool:
-        prefs = tool.Blender.get_addon_preferences()
-        if not prefs.gizmos.draw_gizmos_in_3d_viewport:
-            return False
-
         obj = tool.Blender.get_active_object(is_selected=True)
-        if not obj:
+        if obj is None:
+            return False
+        if not tool.Blender.get_addon_preferences().gizmos.draw_gizmos_in_3d_viewport:
             return False
-
         if len(tool.Blender.get_selected_objects()) != 1:
             return False
-
         element = tool.Ifc.get_entity(obj)
-        if not element or not cls.is_element_type(element):
-            return False
-        return True
+        return bool(element) and cls.is_element_type(element)
 
     def setup(self, context: bpy.types.Context) -> None:
         """Template method for gizmo setup.
@@ -4343,6 +4670,19 @@ class BaseParametricGizmoGroup:
         """
         pass
 
+    # Frame-scoped caches primed at the top of ``refresh()`` and ``draw_prepare()``.
+    # Every per-frame helper — preferences access, view-direction lookup, billboard
+    # rotation — reads these instead of re-deriving the same values, since each
+    # gizmo group ends up needing them 2–5× per frame across its position helpers.
+    _frame_prefs: Any = None
+    _frame_view_dir: tuple[bool, bool] | None = None
+    _frame_billboard_rot: "Matrix | None" = None
+
+    def _prime_frame_caches(self, context: bpy.types.Context, mw: "Matrix") -> None:
+        self._frame_prefs = tool.Blender.get_addon_preferences()
+        self._frame_view_dir = self.get_local_view_direction(context, mw)
+        self._frame_billboard_rot = get_billboard_rotation(context)
+
     def refresh(self, context: bpy.types.Context) -> None:
         """Template method for gizmo refresh.
 
@@ -4357,6 +4697,7 @@ class BaseParametricGizmoGroup:
 
         props = self.get_props(obj)
         mw = obj.matrix_world
+        self._prime_frame_caches(context, mw)
         self.update_editing_gizmos(context, mw, props)
         self.update_dimension_gizmos(mw, props)
         self._refresh_element_specific(context, mw, props)
@@ -4364,8 +4705,10 @@ class BaseParametricGizmoGroup:
     def _refresh_element_specific(self, context: bpy.types.Context, mw: "Matrix", props) -> None:  # noqa: ARG002
         """Override for element-specific refresh logic.
 
-        Called after update_editing_gizmos and update_dimension_gizmos.
-        Examples: door swing gizmos, stair lock/tread/plus/minus gizmos.
+        Called from both refresh() (on state change) and draw_prepare() (per frame),
+        so any override must be idempotent and cheap. Use this to re-position or
+        re-billboard element-specific gizmos (door swing arcs, stair lock/+/- icons,
+        wall cursor icons, etc.).
         """
         pass
 
@@ -4385,10 +4728,11 @@ class BaseParametricGizmoGroup:
             return getattr(tool.Model, self.props_getter)(obj)
         raise NotImplementedError("Subclass must define props_getter or override get_props()")
 
-    @staticmethod
-    def get_addon_prefs():
-        """Get addon preferences (cached accessor)."""
-        return tool.Blender.get_addon_preferences()
+    def get_addon_prefs(self):
+        """Return the addon preferences struct. Inside ``refresh`` / ``draw_prepare``
+        the frame cache is hit; outside (e.g. ``setup``) we fall through to a fresh
+        lookup so callers don't have to know which call path they're on."""
+        return self._frame_prefs if self._frame_prefs is not None else tool.Blender.get_addon_preferences()
 
     def get_decoration_colors(self) -> tuple[tuple[float, float, float], tuple[float, float, float]]:
         """Get default and highlight colors from preferences.
@@ -4507,8 +4851,8 @@ class BaseParametricGizmoGroup:
             scale: Gizmo scale factor (default 0.5)
         """
         if gz := self.get_gizmo_if_visible(gizmo_name):
-            local_transform = Matrix.Translation(Vector((x, y, z))) @ billboard_rot @ Matrix.Scale(scale, 4)
-            gz.matrix_basis = mw @ local_transform
+            world_pos = mw @ Vector((x, y, z))
+            gz.matrix_basis = billboarded_at(world_pos, billboard_rot, scale)
 
     def set_dimension_gizmo_position(
         self,
@@ -4594,28 +4938,12 @@ class BaseParametricGizmoGroup:
     ) -> bpy.types.Gizmo:
         """Create and configure an icon gizmo with standard settings.
 
-        Reduces boilerplate in setup_editing_gizmos.
-
-        Args:
-            gizmo_type: Blender gizmo type identifier (e.g., "VIEW3D_GT_pen")
-            color: RGB color tuple
-            operator: Operator to invoke on click
-            highlight_color: Optional highlight color (defaults to prefs selection color)
-            alpha: Gizmo alpha (default 0.8)
-
-        Returns:
-            Configured gizmo instance.
+        Thin wrapper over `setup_icon_gizmo` that defaults ``highlight_color``
+        to the addon-prefs selection color via ``get_decoration_colors``.
         """
         if highlight_color is None:
             _, highlight_color = self.get_decoration_colors()
-
-        gizmo = self.gizmos.new(gizmo_type)
-        gizmo.use_draw_scale = False
-        gizmo.color = color
-        gizmo.color_highlight = highlight_color
-        gizmo.alpha = alpha
-        gizmo.target_set_operator(operator)
-        return gizmo
+        return setup_icon_gizmo(self, gizmo_type, color, highlight_color, operator, alpha)
 
     def setup_editing_gizmos(self, context: bpy.types.Context) -> None:
         default_color, highlight_color = self.get_decoration_colors()
@@ -4696,6 +5024,7 @@ class BaseParametricGizmoGroup:
             gizmo.delta_scale = config.delta_scale
             gizmo.prop_name = config.prop_name  # Auto-derived in __post_init__
             gizmo.gizmo_group = self
+            gizmo.text_formatter = config.text_formatter
             gizmo.color = self.get_color_from_name(config.color)
             gizmo.color_highlight = highlight_color
             gizmo.alpha = 1.0
@@ -4723,10 +5052,9 @@ class BaseParametricGizmoGroup:
 
             gizmo.hide = False
 
-            # Priority: config.matrix_position > get_dimension_matrix_* method > Identity
+            # Priority: config.matrix_position > get_dimension_matrix_* method > Identity.
             if config.matrix_position:
-                position = config.matrix_position(props)
-                base_matrix = self.compose_gizmo_matrix(position, config.axis)
+                base_matrix = self.compose_gizmo_matrix(config.matrix_position(props), config.axis)
             else:
                 matrix_method = getattr(self, f"get_dimension_matrix_{config.attr_name}", None)
                 base_matrix = matrix_method(props) if matrix_method else Matrix.Identity(4)
@@ -4758,7 +5086,7 @@ class BaseParametricGizmoGroup:
         """
         return (0.0, 0.0)
 
-    def get_icon_y_offset(self, context: bpy.types.Context, mw: Matrix) -> float:
+    def get_icon_y_offset(self, context: bpy.types.Context, mw: Matrix) -> float:  # noqa: ARG002
         """Get Y offset for icons based on view direction.
 
         Uses get_icon_y_extent() to determine how far to offset icons based on
@@ -4774,8 +5102,7 @@ class BaseParametricGizmoGroup:
         props = self.get_props(obj)
         positive_extent, negative_extent = self.get_icon_y_extent(props)
 
-        viewing_from_negative_y, _ = self.get_local_view_direction(context, mw)
-        if viewing_from_negative_y:
+        if self._frame_view_dir[0]:
             return -negative_extent
         return positive_extent
 
@@ -4783,34 +5110,40 @@ class BaseParametricGizmoGroup:
         """Update editing icon gizmo positions to billboard toward camera."""
         icon_z = self.get_element_height(props) + self.ICON_Z_OFFSET
         icon_y = self.get_icon_y_offset(context, mw)
-        billboard_rot = get_billboard_rotation(context)
-
-        # This ensures icons face camera regardless of object rotation
-        local_pos_validate = Vector((self.ICON_VALIDATE_X, icon_y, icon_z))
-        world_pos_validate = mw @ local_pos_validate
-
-        icon_matrix_base = Matrix.Translation(world_pos_validate) @ billboard_rot @ Matrix.Scale(0.5, 4)
-
+        billboard_rot = self._frame_billboard_rot
+        # set_icon_gizmo_position no-ops on hidden gizmos (via get_gizmo_if_visible),
+        # so the hide flag must be set first; that gates whether the matrix is written.
         if props.is_editing:
             self.pen_gizmo.hide = True
             self.validate_gizmo.hide = self.is_gizmo_hidden_by_modal(self.validate_gizmo)
-            self.validate_gizmo.matrix_basis = icon_matrix_base
-
+            self.set_icon_gizmo_position(
+                "validate_gizmo", mw=mw, x=self.ICON_VALIDATE_X, y=icon_y, z=icon_z, billboard_rot=billboard_rot
+            )
             self.cancel_gizmo.hide = self.is_gizmo_hidden_by_modal(self.cancel_gizmo)
-            local_pos_cancel = Vector((self.ICON_VALIDATE_X + self.ICON_CANCEL_X, icon_y, icon_z))
-            world_pos_cancel = mw @ local_pos_cancel
-            self.cancel_gizmo.matrix_basis = Matrix.Translation(world_pos_cancel) @ billboard_rot @ Matrix.Scale(0.5, 4)
-
+            self.set_icon_gizmo_position(
+                "cancel_gizmo",
+                mw=mw,
+                x=self.ICON_VALIDATE_X + self.ICON_CANCEL_X,
+                y=icon_y,
+                z=icon_z,
+                billboard_rot=billboard_rot,
+            )
             if self.cycle_type_operator:
                 self.cycle_gizmo.hide = self.is_gizmo_hidden_by_modal(self.cycle_gizmo)
-                local_pos_cycle = Vector((self.ICON_VALIDATE_X + self.ICON_CYCLE_X, icon_y, icon_z))
-                world_pos_cycle = mw @ local_pos_cycle
-                self.cycle_gizmo.matrix_basis = (
-                    Matrix.Translation(world_pos_cycle) @ billboard_rot @ Matrix.Scale(0.30, 4)
+                self.set_icon_gizmo_position(
+                    "cycle_gizmo",
+                    mw=mw,
+                    x=self.ICON_VALIDATE_X + self.ICON_CYCLE_X,
+                    y=icon_y,
+                    z=icon_z,
+                    billboard_rot=billboard_rot,
+                    scale=0.30,
                 )
         else:
             self.pen_gizmo.hide = self.is_gizmo_hidden_by_modal(self.pen_gizmo)
-            self.pen_gizmo.matrix_basis = icon_matrix_base
+            self.set_icon_gizmo_position(
+                "pen_gizmo", mw=mw, x=self.ICON_VALIDATE_X, y=icon_y, z=icon_z, billboard_rot=billboard_rot
+            )
             self.validate_gizmo.hide = True
             self.cancel_gizmo.hide = True
             if self.cycle_type_operator:
@@ -4819,16 +5152,26 @@ class BaseParametricGizmoGroup:
     def draw_prepare(self, context: bpy.types.Context) -> None:
         """Called before drawing - updates gizmos to face camera.
 
-        This method updates editing gizmos and dimension gizmos.
-        Subclasses can override _update_dimension_gizmo_positions() to customize
-        dimension gizmo positioning based on view direction.
+        This method updates editing gizmos, dimension gizmos, and element-specific
+        gizmos. Subclasses can override _update_dimension_gizmo_positions() to
+        customize dimension gizmo positioning, and _refresh_element_specific() to
+        re-billboard element-specific gizmos per frame.
         """
         obj = context.active_object
         if not obj:
             return
         props = self.get_props(obj)
         mw = obj.matrix_world
+        self._prime_frame_caches(context, mw)
         self.update_editing_gizmos(context, mw, props)
+        # `update_dimension_gizmos` flips the dimension gizmos' `hide` flag
+        # based on `props.is_editing` + per-config visibility conditions.
+        # `refresh()` already calls it, but `refresh()` only fires on depsgraph
+        # events — a `finish_editing_*` operator that toggles `is_editing` to
+        # False without mutating IFC (e.g. wall no-op commit, cancel) does not
+        # trigger a depsgraph update, so without this call the dimension gizmos
+        # would stay visible until the next user input.
+        self.update_dimension_gizmos(mw, props)
 
         self._update_dimension_gizmo_positions(context, mw, props)
 
@@ -4836,6 +5179,8 @@ class BaseParametricGizmoGroup:
         for _, gizmo in self.iter_visible_dimension_gizmos():
             gizmo.draw_prepare(context)
 
+        self._refresh_element_specific(context, mw, props)
+
     def _update_dimension_gizmo_positions(
         self, context: bpy.types.Context, mw: "Matrix", props  # noqa: ARG002
     ) -> None:

src/bonsai/bonsai/bim/module/drawing/helper.py

@@ -313,7 +313,7 @@ def format_distance(
             if not feet and not add_inches:
                 tx_dist += str(feet) + "'"
 
-            if not feet and add_inches:
+            if not feet and add_inches and unit_length != "INCHES":
                 if value < 0:
                     tx_dist += "-0' - "
                 else:

src/bonsai/bonsai/bim/module/drawing/operator.py

@@ -246,17 +246,17 @@ class CreateDrawing(bpy.types.Operator):
         + "Add the CTRL modifier to optionally open drawings to view them as\n"
         + "they are created"
     )
-    print_all: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    print_all: bpy.props.BoolProperty(
         name="Print All",
         default=False,
         options={"SKIP_SAVE"},
     )
-    open_viewer: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    open_viewer: bpy.props.BoolProperty(
         name="Open in Viewer",
         default=False,
         options={"SKIP_SAVE"},
     )
-    sync: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    sync: bpy.props.BoolProperty(
         name="Sync Before Creating Drawing",
         description="Could save some time if you're sure IFC and current Blender session are already in sync",
         default=True,
@@ -2322,14 +2322,14 @@ class ActivateDrawingBase(tool.Ifc.Operator):
         + "SHIFT+CLICK to load a quick preview of the drawing view"
     )
 
-    drawing: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
-    should_view_from_camera: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    drawing: bpy.props.IntProperty()
+    should_view_from_camera: bpy.props.BoolProperty(
         name="Should View From Camera",
         description="Move view to the activated drawing's camera position.",
         default=True,
         options={"SKIP_SAVE"},
     )
-    use_quick_preview: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    use_quick_preview: bpy.props.BoolProperty(
         name="Use Quick Preview",
         description="Just move the camera to the drawing view, without loading anything else.",
         default=False,
@@ -3635,14 +3635,12 @@ class ToggleTargetView(bpy.types.Operator):
     bl_label = "Toggle Target View"
     bl_options = {"REGISTER", "UNDO"}
 
-    target_view: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
-    toggle_all: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    target_view: bpy.props.StringProperty()
+    toggle_all: bpy.props.BoolProperty(
         default=False,
         options={"SKIP_SAVE"},
     )
-    option: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
-        items=[(i, i, "") for i in get_args(ToggleOption)]
-    )
+    option: bpy.props.EnumProperty(items=[(i, i, "") for i in get_args(ToggleOption)])
 
     if TYPE_CHECKING:
         target_view: str

src/bonsai/bonsai/bim/module/drawing/prop.py

@@ -860,13 +860,13 @@ class BIMTextProperties(PropertyGroup):
     is_editing: BoolProperty(name="Is Editing", default=False)
     literals: CollectionProperty(name="Literals", type=LiteralProps)
     newline_at: IntProperty(name="Newline At")
-    symbol: EnumProperty(  # pyright: ignore[reportRedeclaration]
+    symbol: EnumProperty(
         name="Symbol",
         description="Symbol from symbols.svg to use for this text.",
         items=[(s, s, "") for s in ["NO SYMBOL", "CUSTOM SYMBOL"] + tool.Drawing.DEFAULT_SYMBOLS],
         default="NO SYMBOL",
     )
-    custom_symbol: StringProperty(  # pyright: ignore[reportRedeclaration]
+    custom_symbol: StringProperty(
         name="Custom Symbol",
         description="Non-default symbol to use for this text.",
     )

src/bonsai/bonsai/bim/module/geometry/operator.py

@@ -85,7 +85,7 @@ class EditObjectPlacement(bpy.types.Operator, tool.Ifc.Operator):
 class OverrideMeshSeparate(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.override_mesh_separate"
     bl_label = "IFC Mesh Separate"
-    blender_op = bpy.ops.mesh.separate.get_rna_type()
+    blender_op = bpy.ops.mesh.separate.get_rna_type()  # ty: ignore[missing-argument]
     bl_description = blender_op.description + ".\nAlso makes sure changes are in sync with IFC."
     bl_options = {"REGISTER", "UNDO"}
     blender_type_prop = blender_op.properties["type"]
@@ -246,7 +246,7 @@ class OverrideMeshSeparate(bpy.types.Operator, tool.Ifc.Operator):
 
 class OverrideOriginSet(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.override_origin_set"
-    blender_op = bpy.ops.object.origin_set.get_rna_type()
+    blender_op = bpy.ops.object.origin_set.get_rna_type()  # ty: ignore[missing-argument]
     bl_label = "IFC Origin Set"
     bl_description = (
         blender_op.description + ".\nAlso makes sure changes are in sync with IFC (operator works only on IFC objects)"
@@ -801,7 +801,7 @@ def calc_delete_is_batch(ifc_file: ifcopenshell.file, context: bpy.types.Context
 class OverrideDelete(bpy.types.Operator):
     bl_idname = "bim.override_object_delete"
     bl_label = "IFC Delete"
-    blender_op = bpy.ops.object.delete.get_rna_type()
+    blender_op = bpy.ops.object.delete.get_rna_type()  # ty: ignore[missing-argument]
     bl_description = (
         blender_op.description
         + ".\nAlso makes sure changes in sync with IFC."
@@ -821,7 +821,7 @@ class OverrideDelete(bpy.types.Operator):
     def poll(cls, context):
         # Match `object.delete` poll for consistency.
         # `object.delete` poll just checks for OBJECT mode.
-        poll = bpy.ops.object.delete.poll()
+        poll = bpy.ops.object.delete.poll()  # ty: ignore[missing-argument]
         if poll:
             return True
         cls.poll_message_set("Only available in OBJECT mode")
@@ -1045,7 +1045,7 @@ class SelectedIdsData(NamedTuple):
 class OverrideOutlinerDelete(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.override_outliner_delete"
     bl_label = "IFC Delete"
-    blender_op = bpy.ops.outliner.delete.get_rna_type()
+    blender_op = bpy.ops.outliner.delete.get_rna_type()  # ty: ignore[missing-argument]
     bl_description = (
         blender_op.description
         + ".\nAlso makes sure changes in sync with IFC."
@@ -1060,7 +1060,7 @@ class OverrideOutlinerDelete(bpy.types.Operator, tool.Ifc.Operator):
     def poll(cls, context) -> bool:
         # Match `outliner.delete` poll for consistency.
         # `outliner.delete` just checks `area.type` == `OUTLINER`.
-        poll = bpy.ops.outliner.delete.poll()
+        poll = bpy.ops.outliner.delete.poll()  # ty: ignore[missing-argument]
         if poll:
             return True
         cls.poll_message_set("Only available from Outliner.")
@@ -1164,7 +1164,7 @@ class OverrideDuplicateMove(bpy.types.Operator):
     def poll(cls, context) -> bool:
         # Match `object.duplicate_move` poll for consistency.
         # `object.duplicate_move` poll checks for OBJECT mode.
-        poll = bpy.ops.object.duplicate_move.poll()
+        poll = bpy.ops.object.duplicate_move.poll()  # ty: ignore[missing-argument]
         if poll:
             return True
         cls.poll_message_set("Only available in OBJECT mode")
@@ -1183,7 +1183,7 @@ class OverrideDuplicateMove(bpy.types.Operator):
         operator: bpy.types.Operator, context: bpy.types.Context, linked: bool = False
     ) -> set["rna_enums.OperatorReturnItems"]:
         # Deep magick from the dawn of time
-        if tool.Ifc.get():
+        if tool.Ifc.get() and tool.Model.has_selected_ifc_objects(include_active=False):
             IfcStore.execute_ifc_operator(operator, context)
             return {"FINISHED"}
 
@@ -1287,6 +1287,11 @@ class OverrideDuplicateMove(bpy.types.Operator):
                             if part_obj:
                                 all_objects_to_select.add(part_obj)
 
+        # Non-IFC duplicates aren't tracked in old_to_new but are left selected by duplicate_ifc_objects
+        all_objects_to_select.update(
+            obj for obj in context.selected_objects if not tool.Ifc.get_entity(obj)
+        )
+
         # Deselect everything first
         bpy.ops.object.select_all(action="DESELECT")
 
@@ -1908,7 +1913,7 @@ class RefreshLinkedAggregate(bpy.types.Operator, tool.Ifc.Operator):
 class OverrideJoin(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.override_object_join"
     bl_label = "IFC Join"
-    blender_op = bpy.ops.mesh.separate.get_rna_type()
+    blender_op = bpy.ops.mesh.separate.get_rna_type()  # ty: ignore[missing-argument]
     bl_description = (
         blender_op.description
         + ".\nAlso makes sure changes are in sync with IFC."
@@ -1926,7 +1931,7 @@ class OverrideJoin(bpy.types.Operator, tool.Ifc.Operator):
 
     @classmethod
     def poll(cls, context):
-        if not bpy.ops.object.join.poll():
+        if not bpy.ops.object.join.poll():  # ty: ignore[missing-argument]
             cls.poll_message_set("Active object is not EDITable.")
             return False
         if not context.selected_editable_objects:

src/bonsai/bonsai/bim/module/group/operator.py

@@ -43,11 +43,11 @@ class ToggleGroup(bpy.types.Operator, tool.Ifc.Operator):
     bl_label = "Toggle Group"
     bl_options = {"REGISTER", "UNDO"}
 
-    ifc_definition_id: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
-    group_type: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    ifc_definition_id: bpy.props.IntProperty()
+    group_type: bpy.props.EnumProperty(
         items=[(i, i, "") for i in get_args(tool.Group.GroupType)],
     )
-    option: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    option: bpy.props.EnumProperty(
         items=[(i, i, "") for i in get_args(tool.Group.ToggleOption)],
     )
 

src/bonsai/bonsai/bim/module/ifcgit/operator.py

@@ -314,7 +314,7 @@ class SelectConflictEntity(bpy.types.Operator):
     bl_idname = "ifcgit.select_conflict_entity"
     bl_options = {"REGISTER"}
 
-    step_id: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    step_id: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         step_id: int
@@ -515,7 +515,7 @@ class RunGitDiff(bpy.types.Operator):
     )
     bl_options = set()
 
-    save_to_temp: bpy.props.BoolProperty(options={"SKIP_SAVE"})  # pyright: ignore[reportRedeclaration]
+    save_to_temp: bpy.props.BoolProperty(options={"SKIP_SAVE"})
 
     if TYPE_CHECKING:
         save_to_temp: bool
@@ -547,7 +547,7 @@ class RenameBranch(bpy.types.Operator):
     bl_idname = "ifcgit.rename_branch"
     bl_options = {"REGISTER"}
 
-    new_name: bpy.props.StringProperty(name="New name")  # pyright: ignore[reportRedeclaration]
+    new_name: bpy.props.StringProperty(name="New name")
 
     if TYPE_CHECKING:
         new_name: str

src/bonsai/bonsai/bim/module/light/operator.py

@@ -272,21 +272,21 @@ class RadianceRender(bpy.types.Operator):
                     + '''" map_u map_v
 0
 1 0.5
- 
+
 # This is a multiplier to colour balance the env map
 # In this case, it provides a rough ground luminance from 3k-5k
 env_map colorfunc env_colour
 4 100 100 100 .
 0
 0
- 
+
 # .37 .57 1.5 is measured from a HDRI image
 # It is multiplied by a factor such that grey(r,g,b) = 1
 skyfunc colorfunc sky_colour
 4 .64 .99 2.6 .
 0
 0
- 
+
 void mixpict composite
 7 env_colour sky_colour grey "'''
                     + hdr_mask_path
@@ -295,22 +295,22 @@ void mixpict composite
                     + """" map_u map_v
 0
 2 0.5 1
- 
+
 composite glow env_map_glow
 0
 0
 4 1 1 1 0
- 
+
 env_map_glow source sky
 0
 0
 4 0 0 1 180
- 
+
 env_colour glow ground_glow
 0
 0
 4 1 1 1 0
- 
+
 ground_glow source ground
 0
 0
@@ -566,7 +566,7 @@ class LightPickCoordinates(bpy.types.Operator):
     )
     bl_options = {"REGISTER", "UNDO"}
 
-    use_current_location: bpy.props.BoolProperty(options={"SKIP_SAVE"})  # pyright: ignore[reportRedeclaration]
+    use_current_location: bpy.props.BoolProperty(options={"SKIP_SAVE"})
 
     if TYPE_CHECKING:
         use_current_location: bool

src/bonsai/bonsai/bim/module/material/operator.py

@@ -630,13 +630,23 @@ class EditAssignedMaterial(bpy.types.Operator, tool.Ifc.Operator):
                     slab.DumbSlabPlaner().regenerate_from_layer_set(layer_set)
 
             if material_set_usage.is_a("IfcMaterialProfileSetUsage"):
-                if "CardinalPoint" in attributes:
+                if "CardinalPoint" in attributes and attributes["CardinalPoint"] is not None:
                     attributes["CardinalPoint"] = int(attributes["CardinalPoint"])
                 ifcopenshell.api.material.edit_profile_usage(
                     self.file,
                     usage=material_set_usage,
                     attributes=attributes,
                 )
+
+                for obj in objects:
+                    obj_element = tool.Ifc.get_entity(obj)
+                    if not obj_element:
+                        continue
+                    obj_material_usage = ifcopenshell.util.element.get_material(obj_element)
+                    if obj_material_usage and obj_material_usage.is_a("IfcMaterialProfileSetUsage"):
+                        obj_material_usage.CardinalPoint = material_set_usage.CardinalPoint
+                        obj_material_usage.ReferenceExtent = material_set_usage.ReferenceExtent
+
                 model_profile.DumbProfileRecalculator().recalculate(objects)
 
         bpy.ops.bim.disable_editing_assigned_material(obj=active_obj.name)

src/bonsai/bonsai/bim/module/misc/operator.py

@@ -136,7 +136,7 @@ class SplitAlongEdge(bpy.types.Operator, tool.Ifc.Operator):
         "Will unassign element from a type if type has a representation."
     )
     bl_options = {"REGISTER", "UNDO"}
-    mode: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    mode: bpy.props.EnumProperty(
         default="BOOLEAN",
         items=tuple((i, i, "") for i in get_args(SplitAlongEdgeMode)),
     )
@@ -359,7 +359,7 @@ class ConfirmQuickFavoriteOperator(bpy.types.Operator):
     bl_idname = "bim.confirm_quick_favorite_operator"
     bl_label = "Confirm Operator"
     bl_options = {"REGISTER", "UNDO"}
-    index: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    index: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         index: int
@@ -452,10 +452,8 @@ class MoveQuickFavoritesItem(bpy.types.Operator):
     bl_idname = "bim.move_quick_favorites_item"
     bl_label = "Move Quick Favorites Item"
     bl_options = {"REGISTER", "UNDO"}
-    index: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
-    direction: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
-        items=[("UP", "Up", ""), ("DOWN", "Down", "")]
-    )
+    index: bpy.props.IntProperty()
+    direction: bpy.props.EnumProperty(items=[("UP", "Up", ""), ("DOWN", "Down", "")])
 
     if TYPE_CHECKING:
         index: int
@@ -474,7 +472,7 @@ class RemoveQuickFavoritesItem(bpy.types.Operator):
     bl_idname = "bim.remove_quick_favorites_item"
     bl_label = "Remove Quick Favorites Item"
     bl_options = {"REGISTER", "UNDO"}
-    index: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    index: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         index: int

src/bonsai/bonsai/bim/module/misc/prop.py

@@ -36,9 +36,9 @@ QuickFavoriteValueType = Literal["float_value", "bool_value", "int_value", "stri
 
 
 class QuickFavoriteEnumItem(PropertyGroup):
-    name: StringProperty(name="Name", default="")  # pyright: ignore[reportRedeclaration]
-    display_name: StringProperty(name="Display Name", default="")  # pyright: ignore[reportRedeclaration]
-    description: StringProperty(name="Description", default="")  # pyright: ignore[reportRedeclaration]
+    name: StringProperty(name="Name", default="")
+    display_name: StringProperty(name="Display Name", default="")
+    description: StringProperty(name="Description", default="")
 
     if TYPE_CHECKING:
         name: str
@@ -51,19 +51,19 @@ def get_enum_items(self: "QuickFavoriteProperty", context: bpy.types.Context | N
 
 
 class QuickFavoriteProperty(PropertyGroup):
-    name: StringProperty(name="Name", default="")  # pyright: ignore[reportRedeclaration]
-    display_name: StringProperty(name="Display Name", default="")  # pyright: ignore[reportRedeclaration]
-    value_prop: EnumProperty(  # pyright: ignore[reportRedeclaration]
+    name: StringProperty(name="Name", default="")
+    display_name: StringProperty(name="Display Name", default="")
+    value_prop: EnumProperty(
         name="Value Prop",
         items=tuple((v, v, "") for v in get_args(QuickFavoriteValueType)),
     )
-    string_value: StringProperty(name="String Value", default="")  # pyright: ignore[reportRedeclaration]
-    float_value: FloatProperty(name="Float Value", default=0.0)  # pyright: ignore[reportRedeclaration]
-    int_value: IntProperty(name="Int Value", default=0)  # pyright: ignore[reportRedeclaration]
-    bool_value: BoolProperty(name="Bool Value", default=False)  # pyright: ignore[reportRedeclaration]
-    enum_value: EnumProperty(name="Enum Value", items=get_enum_items)  # pyright: ignore[reportRedeclaration]
-    enum_items: CollectionProperty(type=QuickFavoriteEnumItem)  # pyright: ignore[reportRedeclaration]
-    is_active: BoolProperty(  # pyright: ignore[reportRedeclaration]
+    string_value: StringProperty(name="String Value", default="")
+    float_value: FloatProperty(name="Float Value", default=0.0)
+    int_value: IntProperty(name="Int Value", default=0)
+    bool_value: BoolProperty(name="Bool Value", default=False)
+    enum_value: EnumProperty(name="Enum Value", items=get_enum_items)
+    enum_items: CollectionProperty(type=QuickFavoriteEnumItem)
+    is_active: BoolProperty(
         name="Is Active",
         description="Only active properties will be added to the operator when invoked from Quick Favorites",
         default=False,
@@ -100,20 +100,20 @@ def get_operator_suggestions(self: "QuickFavoritesItem", context: bpy.types.Cont
 
 
 class QuickFavoritesItem(PropertyGroup):
-    is_expanded: BoolProperty(name="Is Expanded", default=False)  # pyright: ignore[reportRedeclaration]
-    search: StringProperty(  # pyright: ignore[reportRedeclaration]
+    is_expanded: BoolProperty(name="Is Expanded", default=False)
+    search: StringProperty(
         name="Search",
         default="",
         search=get_operator_suggestions,
         # Resetting `search_options`, allowing users only to use suggestions.
         search_options=set(),
     )
-    properties: CollectionProperty(type=QuickFavoriteProperty)  # pyright: ignore[reportRedeclaration]
-    operator_id: StringProperty(  # pyright: ignore[reportRedeclaration]
+    properties: CollectionProperty(type=QuickFavoriteProperty)
+    operator_id: StringProperty(
         name="Operator ID",
         default="",
     )
-    label: StringProperty(  # pyright: ignore[reportRedeclaration]
+    label: StringProperty(
         name="Label",
         description="Label that will be used in Quick Favorites for this operator",
         default="",
@@ -139,15 +139,15 @@ class QuickFavoritesItem(PropertyGroup):
 
 
 class BIMMiscProperties(PropertyGroup):
-    total_storeys: IntProperty(  # pyright: ignore[reportRedeclaration]
+    total_storeys: IntProperty(
         name="Total Storeys",
         description="Number of storeys above object's storey to take into account for resizing",
         default=1,
     )
-    override_colour: FloatVectorProperty(  # pyright: ignore[reportRedeclaration]
+    override_colour: FloatVectorProperty(
         name="Override Colour", subtype="COLOR", default=(1, 0, 0, 1), min=0.0, max=1.0, size=4
     )
-    quick_favorites: CollectionProperty(type=QuickFavoritesItem)  # pyright: ignore[reportRedeclaration]
+    quick_favorites: CollectionProperty(type=QuickFavoritesItem)
 
     if TYPE_CHECKING:
         total_storeys: int

src/bonsai/bonsai/bim/module/model/__init__.py

@@ -15,11 +15,15 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 from typing import NamedTuple
 
 import bpy
 
+import bonsai.tool as tool
+
 from . import (
     array,
     covering,
@@ -70,18 +74,32 @@ classes = (
     workspace.BIM_MT_add_representation_item,
     wall.AddWallsFromSlab,
     wall.AlignWall,
+    wall.CancelEditingWall,
     wall.ChangeExtrusionDepth,
     wall.ChangeExtrusionXAngle,
     wall.ChangeLayerLength,
+    wall.CycleWallOffset,
     wall.DrawPolylineWall,
+    wall.EnableEditingWall,
+    wall.ExtendWallHeightToCursor,
     wall.ExtendWallsToUnderside,
     wall.ExtendWallsToWall,
     wall.ExtendWallsToPolylinePoint,
+    wall.ExtendWallToCursor,
+    wall.FinishEditingWall,
     wall.FlipWall,
+    wall.GizmoWallAddOpening,
+    wall.GizmoWallEdition,
+    wall.GizmoWallExtendVertically,
+    wall.GizmoWallJoinIntersection,
+    wall.JoinWallsIntersection,
     wall.MergeWall,
     wall.OffsetWalls,
     wall.RecalculateWall,
+    wall.RotateWall90,
     wall.SplitWall,
+    wall.SplitWallAtCursor,
+    wall.ToggleWallOpenings,
     wall.UnjoinWalls,
     opening.AddBoolean,
     opening.CloneOpening,
@@ -140,10 +158,12 @@ classes = (
     prop.BIMDoorProperties,
     prop.BIMRailingProperties,
     prop.BIMRoofProperties,
+    prop.BIMWallProperties,
     prop.BIMPolylineProperties,
     prop.BIMExternalParametricGeometryProperties,
     ui.BIM_PT_array,
     ui.BIM_PT_stair,
+    ui.BIM_PT_wall,
     ui.BIM_PT_sverchok,
     ui.BIM_PT_window,
     ui.BIM_PT_door,
@@ -264,12 +284,10 @@ def register():
     bpy.types.Scene.BIMModelProperties = bpy.props.PointerProperty(type=prop.BIMModelProperties)
     bpy.types.Scene.BIMPolylineProperties = bpy.props.PointerProperty(type=prop.BIMPolylineProperties)
     bpy.types.Object.BIMArrayProperties = bpy.props.PointerProperty(type=prop.BIMArrayProperties)
-    bpy.types.Object.BIMStairProperties = bpy.props.PointerProperty(type=prop.BIMStairProperties)
     bpy.types.Object.BIMSverchokProperties = bpy.props.PointerProperty(type=prop.BIMSverchokProperties)
-    bpy.types.Object.BIMWindowProperties = bpy.props.PointerProperty(type=prop.BIMWindowProperties)
-    bpy.types.Object.BIMDoorProperties = bpy.props.PointerProperty(type=prop.BIMDoorProperties)
-    bpy.types.Object.BIMRailingProperties = bpy.props.PointerProperty(type=prop.BIMRailingProperties)
-    bpy.types.Object.BIMRoofProperties = bpy.props.PointerProperty(type=prop.BIMRoofProperties)
+    # Per-parametric-type ``BIM<Name>Properties`` PointerProperties — driven by
+    # ``tool.Parametric.EDIT_TYPES``; adding a registry entry is the single touchpoint.
+    tool.Parametric.register_object_properties(prop)
     bpy.types.Object.BIMExternalParametricGeometryProperties = bpy.props.PointerProperty(
         type=prop.BIMExternalParametricGeometryProperties
     )
@@ -281,6 +299,12 @@ def register():
 
 
 def unregister():
+    # DecorationsHandler is installed lazily by bim.show_openings; tear it down
+    # (along with its persistent depsgraph / undo / redo / load cache handlers)
+    # before the rest of unregister so those handlers can't fire against
+    # half-unloaded module state.
+    opening.DecorationsHandler.uninstall()
+
     if not bpy.app.background:
         for tool_data in reversed(tools):
             bpy.utils.unregister_tool(tool_data.tool)
@@ -288,12 +312,8 @@ def unregister():
     del bpy.types.Scene.BIMModelProperties
     del bpy.types.Scene.BIMPolylineProperties
     del bpy.types.Object.BIMArrayProperties
-    del bpy.types.Object.BIMStairProperties
     del bpy.types.Object.BIMSverchokProperties
-    del bpy.types.Object.BIMWindowProperties
-    del bpy.types.Object.BIMDoorProperties
-    del bpy.types.Object.BIMRailingProperties
-    del bpy.types.Object.BIMRoofProperties
+    tool.Parametric.unregister_object_properties()
     del bpy.types.Object.BIMExternalParametricGeometryProperties
 
     bpy.app.handlers.load_post.remove(handler.load_post)

src/bonsai/bonsai/bim/module/model/door.py

@@ -38,6 +38,7 @@ import bonsai.tool as tool
 from bonsai.bim.module.drawing import gizmos as gizmo
 from bonsai.bim.module.drawing.gizmos import DimensionGizmoConfig
 from bonsai.bim.module.model.window import create_bm_box, create_bm_window
+from bonsai.bim.parametric_lifecycle import FeatureModifierEditMixin
 
 if TYPE_CHECKING:
     from bonsai.bim.module.model.prop import BIMDoorProperties
@@ -566,103 +567,58 @@ class AddDoor(bpy.types.Operator, tool.Ifc.Operator):
         return {"FINISHED"}
 
 
-class CancelEditingDoor(bpy.types.Operator, tool.Ifc.Operator):
+class _DoorEditMixin(FeatureModifierEditMixin):
+    """Type-specific hooks for door parametric-edit operators. Multi-object —
+    iterates ``tool.Blender.get_selected_objects()`` so a finish/cancel applies
+    to every selected door at once."""
+
+    pset_name = "BBIM_Door"
+
+    @classmethod
+    def _iter_targets(cls, context: bpy.types.Context) -> list[bpy.types.Object]:
+        return tool.Blender.get_selected_objects()
+
+    @classmethod
+    def _is_element_type(cls, element):
+        return tool.Blender.Modifier.is_door(element)
+
+    @classmethod
+    def _get_props(cls, obj: bpy.types.Object):
+        return tool.Model.get_door_props(obj)
+
+    @classmethod
+    def _update_modifier_representation(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
+        update_door_modifier_representation(obj)
+
+
+class CancelEditingDoor(_DoorEditMixin, bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.cancel_editing_door"
     bl_label = "Cancel Editing Door on Selected Objects"
     bl_description = "Cancel editing and revert door parameters to their previous values"
     bl_options = {"REGISTER", "UNDO"}
 
-    def cancel_editing_door_on_object(self, obj: bpy.types.Object) -> None:
-        element = tool.Ifc.get_entity(obj)
-        assert element
-        if not tool.Blender.Modifier.is_door(element):
-            return
-        props = tool.Model.get_door_props(obj)
-        data = json.loads(ifcopenshell.util.element.get_pset(element, "BBIM_Door", "Data"))
-        data.update(data.pop("lining_properties"))
-        data.update(data.pop("panel_properties"))
-
-        # restore previous settings since editing was canceled
-        props.set_props_kwargs_from_ifc_data(data)
-
-        body = ifcopenshell.util.representation.get_representation(element, "Model", "Body", "MODEL_VIEW")
-        core.switch_representation(
-            tool.Ifc,
-            tool.Geometry,
-            obj=obj,
-            representation=body,
-        )
-
-        props.is_editing = False
-
-    def _execute(self, context: bpy.types.Context) -> set[str]:  # noqa: ARG002
-        for obj in tool.Blender.get_selected_objects():
-            self.cancel_editing_door_on_object(obj)
-        return {"FINISHED"}
+    def _execute(self, context: bpy.types.Context) -> set[str]:
+        return self._cancel_targets(context)
 
 
-class FinishEditingDoor(bpy.types.Operator, tool.Ifc.Operator):
+class FinishEditingDoor(_DoorEditMixin, bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.finish_editing_door"
     bl_label = "Finish Editing Door on Selected Objects"
     bl_description = "Apply changes and finish editing door parameters"
     bl_options = {"REGISTER", "UNDO"}
 
-    def finish_editing_door_on_object(self, obj: bpy.types.Object) -> None:
-        element = tool.Ifc.get_entity(obj)
-        assert element
-        if not tool.Blender.Modifier.is_door(element):
-            return
-        props = tool.Model.get_door_props(obj)
-
-        door_data = props.get_general_kwargs(convert_to_project_units=True)
-        lining_props = props.get_lining_kwargs(convert_to_project_units=True)
-        panel_props = props.get_panel_kwargs(convert_to_project_units=True)
-
-        door_data["lining_properties"] = lining_props
-        door_data["panel_properties"] = panel_props
-
-        props.is_editing = False
-
-        update_door_modifier_representation(obj)
-        element_type = ifcopenshell.util.element.get_type(element)
-        if element_type:
-            tool.Model.mark_thumbnail_for_update(element_type)
-
-        pset = tool.Pset.get_element_pset(element, "BBIM_Door")
-        door_data = tool.Ifc.get().createIfcText(json.dumps(door_data, default=list))
-        ifcopenshell.api.pset.edit_pset(tool.Ifc.get(), pset=pset, properties={"Data": door_data})
-
-    def _execute(self, context: bpy.types.Context) -> set[str]:  # noqa: ARG002
-        for obj in tool.Blender.get_selected_objects():
-            self.finish_editing_door_on_object(obj)
-        return {"FINISHED"}
+    def _execute(self, context: bpy.types.Context) -> set[str]:
+        return self._finish_targets(context)
 
 
-class EnableEditingDoor(bpy.types.Operator, tool.Ifc.Operator):
+class EnableEditingDoor(_DoorEditMixin, bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_door"
     bl_label = "Enable Editing Door on Selected Objects"
     bl_description = "Enter edit mode to modify door parameters interactively"
     bl_options = {"REGISTER", "UNDO"}
 
-    def edit_door_on_obj(self, obj: bpy.types.Object) -> None:
-        element = tool.Ifc.get_entity(obj)
-        assert element
-        if not tool.Blender.Modifier.is_door(element):
-            return
-        props = tool.Model.get_door_props(obj)
-        data = json.loads(ifcopenshell.util.element.get_pset(element, "BBIM_Door", "Data"))
-        data.update(data.pop("lining_properties"))
-        data.update(data.pop("panel_properties"))
-        data.update(tool.Model.get_constituents_props_data(element))
-
-        # required since we could load pset from .ifc and BIMDoorProperties won't be set
-        props.set_props_kwargs_from_ifc_data(data)
-        props.is_editing = True
-
-    def _execute(self, context: bpy.types.Context) -> set[str]:  # noqa: ARG002
-        for obj in tool.Blender.get_selected_objects():
-            self.edit_door_on_obj(obj)
-        return {"FINISHED"}
+    def _execute(self, context: bpy.types.Context) -> set[str]:
+        return self._enable_targets(context)
 
 
 class RemoveDoor(bpy.types.Operator, tool.Ifc.Operator):
@@ -939,7 +895,7 @@ class GizmoDoorEdition(bpy.types.GizmoGroup, gizmo.BaseParametricGizmoGroup):
 
     def update_swing_gizmos(self, mw: Matrix, props: "BIMDoorProperties") -> None:
         """Update swing gizmo position and color based on editing state."""
-        prefs = tool.Blender.get_addon_preferences()
+        prefs = self.get_addon_prefs()
         door_gizmo_prefs = prefs.gizmos.door
 
         door_type_visible = self.update_gizmo_visibility(

src/bonsai/bonsai/bim/module/model/opening.py

@@ -41,8 +41,187 @@ from mathutils import Matrix, Vector
 
 import bonsai.core.geometry
 import bonsai.tool as tool
+from bonsai.bim import decorator_cache
 from bonsai.bim.module.drawing.decoration import DecoratorData
 
+# Multi-entry cache for the opening preview's dissolved-edges fallback.
+# Single-entry wouldn't fit: the draw handler iterates every active opening
+# per frame, each with its own mesh. Bumped wholesale on the shared
+# decorator-cache token (depsgraph / undo / redo / load), one slot per
+# (mesh.session_uid, angle_limit). Outlier vs. the per-object caches below —
+# consulted only on world-draw-data miss, so the global wipe rarely fires in
+# steady state and the simpler invalidation is enough.
+_dissolved_edges_cache: dict[
+    tuple[int, float],
+    tuple[list[Vector], list[tuple[int, int]]],
+] = {}
+_dissolved_edges_cache_token: int = -1
+
+
+def _get_cached_dissolved_edges(
+    mesh: bpy.types.Mesh,
+    angle_limit: float = radians(1.0),
+) -> tuple[list[Vector], list[tuple[int, int]]]:
+    global _dissolved_edges_cache_token
+    token = decorator_cache.get_decorator_cache_token()
+    if token != _dissolved_edges_cache_token:
+        _dissolved_edges_cache.clear()
+        _dissolved_edges_cache_token = token
+    key = (mesh.session_uid, angle_limit)
+    cached = _dissolved_edges_cache.get(key)
+    if cached is not None:
+        return cached
+    result = tool.Geometry.get_dissolved_edges(mesh, angle_limit=angle_limit)
+    _dissolved_edges_cache[key] = result
+    return result
+
+
+# Per-object epoch: bumped only when this specific object's transform or geometry
+# updates land in the depsgraph delta. Invalidation work scales with the number
+# of changed objects, not total scene size — moving one object leaves every
+# other entry valid. Bumped by the depsgraph handler below; cleared on
+# undo/redo/load alongside the cache dicts.
+_object_epochs: dict[int, int] = {}
+
+
+@bpy.app.handlers.persistent
+def _bump_object_epochs_for_decoration(*args) -> None:
+    # depsgraph_update_post is called as (scene, depsgraph) in 4.x but the
+    # *args signature follows decorator_cache's defensive idiom.
+    depsgraph = args[1] if len(args) >= 2 else None
+    if depsgraph is None or not hasattr(depsgraph, "updates"):
+        return
+    for u in depsgraph.updates:
+        if not isinstance(u.id, bpy.types.Object):
+            continue
+        if not (u.is_updated_geometry or u.is_updated_transform):
+            continue
+        # u.id is the evaluated COW copy; the cache keys are written from the
+        # original Object (read by the draw handler), and session_uid can
+        # differ across the COW boundary. Resolve to the original before keying.
+        original = getattr(u.id, "original", u.id)
+        if original is None:
+            continue
+        uid = original.session_uid
+        _object_epochs[uid] = _object_epochs.get(uid, 0) + 1
+
+
+@bpy.app.handlers.persistent
+def _clear_decoration_caches_globally(*args) -> None:
+    # Undo/redo/load: depsgraph deltas can't be trusted to describe the
+    # transition, so wipe every per-object cache state.
+    _object_epochs.clear()
+    _world_draw_data_cache.clear()
+    _batch_cache.clear()
+
+
+def _decoration_invalidation_hooks() -> tuple:
+    return (
+        bpy.app.handlers.undo_post,
+        bpy.app.handlers.redo_post,
+        bpy.app.handlers.load_post,
+    )
+
+
+def install_decoration_cache_handlers() -> None:
+    if _bump_object_epochs_for_decoration not in bpy.app.handlers.depsgraph_update_post:
+        bpy.app.handlers.depsgraph_update_post.append(_bump_object_epochs_for_decoration)
+    for hook in _decoration_invalidation_hooks():
+        if _clear_decoration_caches_globally not in hook:
+            hook.append(_clear_decoration_caches_globally)
+
+
+def uninstall_decoration_cache_handlers() -> None:
+    try:
+        bpy.app.handlers.depsgraph_update_post.remove(_bump_object_epochs_for_decoration)
+    except ValueError:
+        pass
+    for hook in _decoration_invalidation_hooks():
+        try:
+            hook.remove(_clear_decoration_caches_globally)
+        except ValueError:
+            pass
+
+
+# Per-object world-space draw payload: line_verts (dissolved or ios_edges-filtered),
+# verts (full mesh, indexed by loop_triangles), edges_indices, tris. Entries are
+# (epoch, payload) tuples; lookup compares epoch to _object_epochs[uid], so a
+# stale entry for an object that didn't change since the last build still hits.
+_world_draw_data_cache: dict[
+    int,
+    tuple[
+        int,
+        tuple[
+            list[tuple[float, float, float]],
+            list[tuple[float, float, float]],
+            list[tuple[int, int]],
+            list[tuple[int, ...]],
+        ],
+    ],
+] = {}
+
+
+def _get_cached_world_draw_data(
+    obj: bpy.types.Object,
+) -> tuple[
+    list[tuple[float, float, float]],
+    list[tuple[float, float, float]],
+    list[tuple[int, int]],
+    list[tuple[int, ...]],
+]:
+    uid = obj.session_uid
+    epoch = _object_epochs.get(uid, 0)
+    entry = _world_draw_data_cache.get(uid)
+    if entry is not None and entry[0] == epoch:
+        return entry[1]
+
+    mw = obj.matrix_world
+    verts = [tuple(mw @ v.co) for v in obj.data.vertices]
+    obj.data.calc_loop_triangles()
+    tris = [tuple(t.vertices) for t in obj.data.loop_triangles]
+
+    ios_edges_attribute = obj.data.attributes.get("ios_edges")
+    if ios_edges_attribute:
+        # Loader-curated edges: read the attribute aligned with bm.edges order.
+        bm = bmesh.new()
+        bm.from_mesh(obj.data)
+        edges_indices = [
+            tuple(v.index for v in e.verts) for i, e in enumerate(bm.edges) if ios_edges_attribute.data[i].value
+        ]
+        bm.free()
+        line_verts = verts
+    else:
+        dissolved, edges_indices = _get_cached_dissolved_edges(obj.data)
+        line_verts = [tuple(mw @ v) for v in dissolved]
+
+    result = (line_verts, verts, edges_indices, tris)
+    _world_draw_data_cache[uid] = (epoch, result)
+    return result
+
+
+# GPUBatch cache: skip per-frame batch_for_shader. Entries are (epoch, batch);
+# lookup compares epoch to _object_epochs[uid] so other objects' batches stay
+# alive when one object's depsgraph delta bumps only its own epoch. The cached
+# batches reference GPU-side buffers tied to Blender's built-in shaders, which
+# are themselves cached by name (gpu.shader.from_builtin returns the same
+# handle each call), so they stay drawable across frames.
+_batch_cache: dict[tuple[int, str], tuple[int, "gpu.types.GPUBatch"]] = {}
+
+
+def _get_cached_batch_or_none(cache_key: tuple[int, str]) -> "gpu.types.GPUBatch | None":
+    uid = cache_key[0]
+    epoch = _object_epochs.get(uid, 0)
+    entry = _batch_cache.get(cache_key)
+    if entry is not None and entry[0] == epoch:
+        return entry[1]
+    return None
+
+
+def _store_batch_in_cache(cache_key: tuple[int, str], batch: "gpu.types.GPUBatch") -> None:
+    uid = cache_key[0]
+    epoch = _object_epochs.get(uid, 0)
+    _batch_cache[cache_key] = (epoch, batch)
+
 
 class FilledOpeningGenerator:
     def generate(
@@ -941,7 +1120,6 @@ class SelectBoolean(Operator):
         return {"FINISHED"}
 
 
-# TODO: merge with ProfileDecorator?
 class DecorationsHandler:
     installed = None
 
@@ -951,6 +1129,7 @@ class DecorationsHandler:
             cls.uninstall()
         handler = cls()
         cls.installed = SpaceView3D.draw_handler_add(handler, (context,), "WINDOW", "POST_VIEW")
+        install_decoration_cache_handlers()
 
     @classmethod
     def uninstall(cls):
@@ -959,15 +1138,46 @@ class DecorationsHandler:
         except ValueError:
             pass
         cls.installed = None
+        uninstall_decoration_cache_handlers()
 
-    def draw_batch(self, shader_type, content_pos, color, indices=None):
+    def _get_or_build_batch(self, shader, shader_type, content_pos, indices=None, cache_key=None):
+        if cache_key is not None:
+            cached = _get_cached_batch_or_none(cache_key)
+            if cached is not None:
+                return cached
         if not tool.Blender.validate_shader_batch_data(content_pos, indices):
-            return
-        shader = self.line_shader if shader_type == "LINES" else self.shader
+            return None
         batch = batch_for_shader(shader, shader_type, {"pos": content_pos}, indices=indices)
+        if cache_key is not None:
+            _store_batch_in_cache(cache_key, batch)
+        return batch
+
+    def draw_batch(self, shader_type, content_pos, color, indices=None, cache_key=None):
+        shader = self.line_shader if shader_type == "LINES" else self.shader
+        batch = self._get_or_build_batch(shader, shader_type, content_pos, indices, cache_key=cache_key)
+        if batch is None:
+            return
         shader.uniform_float("color", color)
         batch.draw(shader)
 
+    def _draw_lines_with_occlusion(self, verts, color, edges_indices, occluded_alpha: float = 0.25, cache_key=None):
+        # One batch, two draws: front pass at full color, occluded pass at
+        # `occluded_alpha`. Save/restore depth_test matches the pattern in
+        # bim/module/structural/decorator.py so callers' state survives.
+        batch = self._get_or_build_batch(self.line_shader, "LINES", verts, edges_indices, cache_key=cache_key)
+        if batch is None:
+            return
+        original_depth_test = gpu.state.depth_test_get()
+        gpu.state.depth_test_set("LESS_EQUAL")
+        self.line_shader.uniform_float("color", color)
+        batch.draw(self.line_shader)
+        gpu.state.depth_test_set("GREATER")
+        dimmed = list(color)
+        dimmed[3] = occluded_alpha
+        self.line_shader.uniform_float("color", dimmed)
+        batch.draw(self.line_shader)
+        gpu.state.depth_test_set(original_depth_test)
+
     def __call__(self, context):
         props = tool.Model.get_model_props()
         if not props.openings:
@@ -1039,23 +1249,20 @@ class DecorationsHandler:
                 self.draw_batch("LINES", verts, selected_elements_color, selected_edges)
                 self.draw_batch("POINTS", unselected_vertices, unselected_elements_color)
                 self.draw_batch("POINTS", selected_vertices, selected_elements_color)
+                obj.data.calc_loop_triangles()
+                tris = [tuple(t.vertices) for t in obj.data.loop_triangles]
+                self.draw_batch("TRIS", verts, transparent_color(special_elements_color), tris)
             else:
-                bm = bmesh.new()
-                bm.from_mesh(obj.data)
-
-                verts = [tuple(obj.matrix_world @ v.co) for v in bm.verts]
-                if ios_edges_attribute := obj.data.attributes.get("ios_edges"):
-                    edges = [e for i, e in enumerate(bm.edges) if ios_edges_attribute.data[i].value]
-                else:
-                    edges = bm.edges
-                edges_indices = [tuple([v.index for v in e.verts]) for e in edges]
-
+                line_verts, verts, edges_indices, tris = _get_cached_world_draw_data(obj)
                 color = selected_elements_color if obj in context.selected_objects else special_elements_color
-                self.draw_batch("LINES", verts, color, edges_indices)
-
-            obj.data.calc_loop_triangles()
-            tris = [tuple(t.vertices) for t in obj.data.loop_triangles]
-            self.draw_batch("TRIS", verts, transparent_color(special_elements_color), tris)
+                self._draw_lines_with_occlusion(line_verts, color, edges_indices, cache_key=(obj.session_uid, "lines"))
+                self.draw_batch(
+                    "TRIS",
+                    verts,
+                    transparent_color(special_elements_color),
+                    tris,
+                    cache_key=(obj.session_uid, "tris"),
+                )
 
             if "HalfSpaceSolid" in obj.name:
                 # Arrow shape
@@ -1069,7 +1276,4 @@ class DecorationsHandler:
                 ]
                 edges = [(0, 1), (1, 2), (1, 3), (1, 4), (1, 5)]
                 color = selected_elements_color if obj in context.selected_objects else special_elements_color
-                self.draw_batch("LINES", verts, color, edges)
-
-            if obj.mode != "EDIT":
-                bm.free()
+                self._draw_lines_with_occlusion(verts, color, edges, cache_key=(obj.session_uid, "arrow"))

src/bonsai/bonsai/bim/module/model/preview_base.py

@@ -0,0 +1,206 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2026
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was generated with the assistance of an AI coding tool.
+
+"""Shared helpers for Bonsai's parametric preview flows.
+
+Multiple Bonsai features follow the same Scene-level preview pattern:
+
+    Enable<X>Preview   — validates a selection, populates draft state on
+                         ``Scene.BIMPreviewProperties.<x>``, flips ``is_active``.
+    Gizmo<X>Preview    — polls on ``is_active``, surfaces tunable widgets +
+                         validate/cancel icons.
+    <X>PreviewDecorator — GPU lines drawn while ``is_active`` is True.
+    Finish<X>Preview   — direct ``bpy.ops.bim.<verb>(...)`` call with kwargs
+                         read off the draft state, then clears it.
+    Cancel<X>Preview   — pure state reset.
+
+The MEP bend and wall fillet flows are the two current callers. They write
+their Finish / Cancel operators directly, matching the convention used
+throughout the rest of ``bim/module/model/`` for operator-to-operator
+dispatch (explicit ``bpy.ops.bim.X(kwarg=value)`` at the call site, no
+string indirection). This module hosts the cross-cutting accessors only;
+no base class layer.
+
+The GPU draw-handler lifecycle for ``<X>PreviewDecorator`` lives on the
+feature-neutral ``tool.Blender.ViewportDecorator`` base, which every
+viewport decorator (preview or otherwise) inherits from."""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from typing import Any
+
+import bpy
+
+import bonsai.tool as tool
+
+# --- Props accessors ---------------------------------------------------------
+
+
+def get_preview_props(context: bpy.types.Context, attr: str):
+    """Resolve a child preview PropertyGroup under ``Scene.BIMPreviewProperties``.
+
+    Returns ``None`` if the umbrella isn't attached yet — true briefly
+    during addon register and during plug-out, so polls / draw callbacks
+    must defend against ``None`` rather than assuming the prop is always
+    available."""
+    preview = getattr(context.scene, "BIMPreviewProperties", None)
+    return getattr(preview, attr, None) if preview is not None else None
+
+
+def is_preview_active(context: bpy.types.Context, attr: str) -> bool:
+    """``True`` while a specific preview is open. Used by sibling gizmo
+    polls to hide themselves so the preview is the only interactive
+    surface in the viewport (the bend / fillet preview groups take over
+    the same selection's icon stack)."""
+    props = get_preview_props(context, attr)
+    return bool(props is not None and props.is_active)
+
+
+# --- Lazy closure factories --------------------------------------------------
+#
+# Used by preview gizmo groups when wiring ``BIM_GT_gizmo_dimension``'s
+# ``move_get_cb`` / ``move_set_cb`` callbacks. The closures re-resolve
+# ``bpy.context.scene`` per CALL rather than capturing it at setup() time
+# — the captured Scene's RNA struct can be freed on file open / undo, and
+# referencing a freed struct crashes Blender. Lazy lookup survives the
+# whole undo / reload lifecycle.
+
+
+def make_props_callback(attr: str) -> Callable[[], Any]:
+    """Return a zero-arg callable that lazily fetches the preview props.
+
+    Equivalent to ``getattr(bpy.context.scene.BIMPreviewProperties, attr)``
+    with full defensiveness against missing scene / missing umbrella."""
+
+    def _props():
+        scene = bpy.context.scene
+        preview = getattr(scene, "BIMPreviewProperties", None) if scene else None
+        return getattr(preview, attr, None) if preview is not None else None
+
+    return _props
+
+
+def make_dim_getter(props_callback: Callable[[], Any], field: str) -> Callable[[], float]:
+    """Factory for ``BIM_GT_gizmo_dimension.move_get_cb`` reading a single
+    FloatProperty off the live preview state. Returns ``0.0`` defensively
+    when the props are temporarily unavailable so the widget doesn't crash
+    Blender during plug-out / reload."""
+
+    def _get() -> float:
+        props = props_callback()
+        return getattr(props, field) if props is not None else 0.0
+
+    return _get
+
+
+def make_dim_setter(
+    props_callback: Callable[[], Any],
+    field: str,
+    min_value: float = 0.001,
+) -> Callable[[float], None]:
+    """Factory for ``BIM_GT_gizmo_dimension.move_set_cb`` writing a single
+    FloatProperty + tagging viewport areas for redraw so the GPU preview
+    decorator tracks the value live during drag. Clamps at ``min_value``
+    to match the FloatProperty's declared lower bound."""
+
+    def _set(value: float) -> None:
+        props = props_callback()
+        if props is None:
+            return
+        setattr(props, field, max(min_value, float(value)))
+        tool.Blender.update_all_viewports()
+
+    return _set
+
+
+# --- Shared Enable lifecycle helpers -----------------------------------------
+
+
+def sync_uncommitted_moves(objects: list) -> None:
+    """Push any Blender-side translation / rotation of ``objects`` back to
+    their IFC ``ObjectPlacement`` before a preview decorator starts reading
+    ``obj.matrix_world`` per frame.
+
+    Without this sync, a user who grabbed-moved an object but didn't commit
+    the move sees the live preview at the dragged position while the final
+    commit lands at the stale IFC position — a confusing "where did my
+    preview go?" experience. Both bend and fillet enable paths call this
+    on the relevant pair just before activating the preview."""
+    for obj in objects:
+        tool.Geometry.commit_placement_if_moved(obj, apply_scale=False)
+
+
+# --- Esc dispatch ------------------------------------------------------------
+
+PREVIEW_CANCEL_OPS: tuple[tuple[str, str], ...] = (
+    ("bend", "cancel_bend_preview"),
+    ("wall_fillet", "cancel_wall_fillet_preview"),
+)
+"""Registry of ``(child PointerProperty on Scene.BIMPreviewProperties, bim
+operator name)`` consulted by the Esc handler. Adding a new preview means
+appending one tuple; the forward-compat test pins that every preview
+PropertyGroup with ``is_active`` has an entry here."""
+
+
+def try_cancel_active_preview(context: bpy.types.Context) -> bool:
+    """Cancel every registered preview that is currently active.
+
+    Returns ``True`` iff at least one preview was cancelled. Multiple
+    previews can be simultaneously active (e.g. a stale bend preview opened
+    just before the user starts a wall fillet) — one Esc must clear them
+    all rather than forcing the user to tap Esc once per preview.
+
+    Tags 3D viewports for redraw on success — the Esc keymap entry runs
+    outside a viewport mouse event so the gizmo poll wouldn't re-evaluate
+    until the next interaction without an explicit redraw."""
+    cancelled = False
+    for attr, op_name in PREVIEW_CANCEL_OPS:
+        if is_preview_active(context, attr):
+            getattr(bpy.ops.bim, op_name)()
+            cancelled = True
+    if cancelled:
+        tool.Blender.update_all_viewports(context)
+    return cancelled
+
+
+def discard_pending_previews(scene: bpy.types.Scene) -> None:
+    """Clear every active preview under ``Scene.BIMPreviewProperties`` so
+    saved preview state never resurfaces on file load.
+
+    Mirrors ``tool.Parametric.heal_stale_edit_flags`` for the object-level
+    parametric-edit lifecycle — except previews are *discarded* rather than
+    validated. A preview's only UI cue is its in-viewport widget; reloading
+    a ``.blend`` saved mid-preview restores the flag but not the surrounding
+    user attention, and a stuck ``is_active`` silently hides every sibling
+    gizmo poll gated on it.
+
+    Iterates ``PREVIEW_CANCEL_OPS`` so any preview registered for Esc
+    cancellation is automatically covered here too. Sets ``is_active``
+    directly rather than dispatching the cancel operator: load_post may
+    fire before ``bpy.context.screen`` is reattached, and the cancel
+    operators bail on ``context.screen is None``."""
+    preview = getattr(scene, "BIMPreviewProperties", None)
+    if preview is None:
+        return
+    for attr, _op_name in PREVIEW_CANCEL_OPS:
+        child = getattr(preview, attr, None)
+        if child is not None and getattr(child, "is_active", False):
+            child.is_active = False

src/bonsai/bonsai/bim/module/model/product.py

@@ -545,7 +545,7 @@ class ChangeTypePage(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.change_type_page"
     bl_label = "Change Type Page"
     bl_options = {"REGISTER"}
-    page: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    page: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         page: int

src/bonsai/bonsai/bim/module/model/profile.py

@@ -271,7 +271,7 @@ class ExtendProfile(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.extend_profile"
     bl_label = "Extend Profile"
     bl_options = {"REGISTER", "UNDO"}
-    join_type: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    join_type: bpy.props.EnumProperty(
         items=[("-", "Unjoin", ""), ("L", "L", ""), ("V", "V", ""), ("T", "T", "")],
         default="-",
     )

src/bonsai/bonsai/bim/module/model/prop.py

@@ -15,6 +15,8 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 import math
 from collections.abc import Callable
@@ -193,6 +195,32 @@ def update_stair(self: "BIMStairProperties", context: bpy.types.Context) -> None
         _get_updater("stair", "regenerate_stair_mesh")(obj)
 
 
+def update_wall(self: "BIMWallProperties", context: bpy.types.Context) -> None:
+    """Regenerate wall mesh preview when property changes. Does NOT touch IFC."""
+    obj = context.active_object
+    if obj and self.is_editing:
+        _get_updater("wall", "regenerate_wall_mesh_from_props")(obj)
+
+
+def update_wall_offset_baseline(self: "BIMWallProperties", context: bpy.types.Context) -> None:
+    """Recompute the preview-only ``offset`` when the draft baseline cycles. Does not touch IFC.
+
+    ``offset`` itself has no ``update`` callback on purpose — adding one would make
+    every baseline cycle rebuild the bmesh twice (once via offset's callback, once
+    explicitly below)."""
+    obj = context.active_object
+    if not (obj and self.is_editing):
+        return
+    t = self.thickness
+    if self.desired_offset_baseline == "CENTER":
+        self.offset = -t / 2
+    elif self.desired_offset_baseline == "INTERIOR":
+        self.offset = -t
+    else:  # EXTERIOR
+        self.offset = 0.0
+    _get_updater("wall", "regenerate_wall_mesh_from_props")(obj)
+
+
 def update_railing(self: "BIMRailingProperties", context: bpy.types.Context) -> None:
     """Regenerate railing mesh when property changes."""
     if self.is_editing:
@@ -1631,6 +1659,118 @@ class BIMRoofProperties(PropertyGroup):
             setattr(target_props, prop_name, prop_value)
 
 
+class BIMWallProperties(PropertyGroup):
+    """Transient draft state for parametric wall gizmo editing.
+
+    Populated from IFC on `bim.enable_editing_wall`, mutated by gizmo drags during edit
+    (preview only — no IFC writes), and either committed by `bim.finish_editing_wall`
+    or discarded by `bim.cancel_editing_wall`.
+
+    The `snap_*` fields are the values captured on enable; `finish_editing_wall` compares
+    current vs snap to skip unchanged params and guarantee a no-op session leaves the
+    IFC file byte-identical.
+    """
+
+    is_editing: bpy.props.BoolProperty(
+        default=False,
+        description="True while wall parametric edit mode is active.",
+    )
+    mesh_dirty: bpy.props.BoolProperty(
+        default=False,
+        options={"HIDDEN", "SKIP_SAVE"},
+        description=(
+            "True while the visible mesh is the preview box; cleared once the real "
+            "IFC-derived geometry is restored (on commit or cancel)."
+        ),
+    )
+    length: bpy.props.FloatProperty(
+        name="Length",
+        default=1.0,
+        min=0.01,
+        subtype="DISTANCE",
+        update=update_wall,
+        description="Wall length along its reference axis (preview value; committed on finish).",
+    )
+    height: bpy.props.FloatProperty(
+        name="Height",
+        default=3.0,
+        min=0.01,
+        subtype="DISTANCE",
+        update=update_wall,
+        description="Wall vertical height (preview value; committed on finish).",
+    )
+    x_angle: bpy.props.FloatProperty(
+        name="Slope (X Angle)",
+        default=0.0,
+        soft_min=-math.pi / 3,
+        soft_max=math.pi / 3,
+        subtype="ANGLE",
+        update=update_wall,
+        description="Slope angle: tilt of the wall's top face along +Y (preview value; committed on finish).",
+    )
+    thickness: bpy.props.FloatProperty(
+        name="Thickness",
+        default=0.2,
+        min=0.001,
+        subtype="DISTANCE",
+        description="Wall thickness captured from IFC at edit-enable; not gizmo-bound.",
+    )
+    offset: bpy.props.FloatProperty(
+        name="Offset",
+        default=0.0,
+        subtype="DISTANCE",
+        description="Layer-set offset captured from IFC at edit-enable; driven by desired_offset_baseline.",
+    )
+    desired_offset_baseline: bpy.props.EnumProperty(
+        items=[
+            ("EXTERIOR", "Exterior", "Reference axis at the exterior face"),
+            ("CENTER", "Center", "Reference axis at the wall centreline"),
+            ("INTERIOR", "Interior", "Reference axis at the interior face"),
+        ],
+        name="Desired Offset Baseline",
+        default="CENTER",
+        update=update_wall_offset_baseline,
+        description="Which face of the wall the reference axis aligns to (preview value; committed on finish).",
+    )
+    anchor_x: bpy.props.FloatProperty(
+        default=0.0,
+        subtype="DISTANCE",
+        description="Local-X of the wall's axis polyline start, so the preview box lands where the IFC mesh does.",
+    )
+
+    snap_length: bpy.props.FloatProperty(description="Snapshot of length at edit-enable; commit skips no-op writes.")
+    snap_height: bpy.props.FloatProperty(description="Snapshot of height at edit-enable; commit skips no-op writes.")
+    snap_thickness: bpy.props.FloatProperty(
+        description="Snapshot of thickness at edit-enable; commit skips no-op writes."
+    )
+    snap_offset: bpy.props.FloatProperty(description="Snapshot of offset at edit-enable; commit skips no-op writes.")
+    snap_x_angle: bpy.props.FloatProperty(
+        subtype="ANGLE",
+        description="Snapshot of x_angle at edit-enable; commit skips no-op writes.",
+    )
+    snap_offset_baseline: bpy.props.StringProperty(
+        default="",
+        description="Snapshot of desired_offset_baseline at edit-enable; commit skips no-op writes.",
+    )
+
+    if TYPE_CHECKING:
+        is_editing: bool
+        mesh_dirty: bool
+        length: float
+        height: float
+        x_angle: float
+        thickness: float
+        offset: float
+        desired_offset_baseline: Literal["EXTERIOR", "CENTER", "INTERIOR"]
+        anchor_x: float
+        snap_length: float
+        snap_height: float
+        snap_thickness: float
+        snap_offset: float
+        snap_x_angle: float
+        snap_offset_baseline: str
+
+
 class SnapMousePoint(PropertyGroup):
     x: bpy.props.FloatProperty(name="X")
     y: bpy.props.FloatProperty(name="Y")
@@ -1729,20 +1869,20 @@ def poll_sverchok_nodes(self: "BIMExternalParametricGeometryProperties", node_tr
 
 
 class BIMExternalParametricGeometryProperties(bpy.types.PropertyGroup):
-    is_editing: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    is_editing: bpy.props.BoolProperty(
         name="Is Editing Paramteric Geometry",
         description="Toggle editing parametric geometry.",
         default=False,
         update=update_is_editing,
     )
-    geometry_source: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    geometry_source: bpy.props.EnumProperty(
         name="Geometry Source",
         items=[
             ("GEONODES", "Geometry Nodes", ""),
             ("IFCSVERCHOK", "IFC Sverchok", ""),
         ],
     )
-    geo_nodes: bpy.props.PointerProperty(  # pyright: ignore[reportRedeclaration]
+    geo_nodes: bpy.props.PointerProperty(
         name="Geometry Nodes",
         description="Geometry nodes tree to use as a source for representation.",
         type=bpy.types.GeometryNodeTree,
@@ -1750,7 +1890,7 @@ class BIMExternalParametricGeometryProperties(bpy.types.PropertyGroup):
         poll=lambda self, node_tree: not node_tree.name.startswith("BBIM_EPG"),
     )
 
-    sverchok_nodes: bpy.props.PointerProperty(  # pyright: ignore[reportRedeclaration]
+    sverchok_nodes: bpy.props.PointerProperty(
         name="Sverchok Nodes",
         description="Sverchok node tree to use as a source for representation.",
         type=bpy.types.NodeTree,

src/bonsai/bonsai/bim/module/model/railing.py

@@ -34,6 +34,7 @@ import bonsai.core.root
 import bonsai.tool as tool
 from bonsai.bim.module.model.data import RailingData, refresh
 from bonsai.bim.module.model.decorator import ProfileDecorator
+from bonsai.bim.parametric_lifecycle import PathPreservingEditMixin
 
 # reference:
 # https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcRailing.htm
@@ -92,7 +93,6 @@ def update_railing_modifier_ifc_data(context: bpy.types.Context) -> None:
         si_conversion = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())
 
         representation_data = {
-            "railing_type": props.railing_type,
             "context": body,
             "railing_path": railing_path,
             "use_manual_supports": props.use_manual_supports,
@@ -406,66 +406,65 @@ class CopyRailingParameters(bpy.types.Operator, tool.Ifc.Operator):
         return {"FINISHED"}
 
 
-class EnableEditingRailing(bpy.types.Operator, tool.Ifc.Operator):
-    bl_idname = "bim.enable_editing_railing"
-    bl_label = "Enable Editing Railing"
-    bl_options = {"REGISTER"}
+class _RailingEditMixin(PathPreservingEditMixin):
+    """Type-specific hooks for railing parametric-edit operators. Single-object
+    (active_object). ``path_data`` is preserved through the edit; the separate
+    ``Enable/Finish/CancelEditingRailingPath`` operators handle path editing."""
 
-    def _execute(self, context):
-        obj = context.active_object
-        assert obj
-        props = tool.Model.get_railing_props(obj)
-        data = tool.Model.get_modeling_bbim_pset_data(obj, "BBIM_Railing")["data_dict"]
+    pset_name = "BBIM_Railing"
+
+    @classmethod
+    def _is_element_type(cls, element):
+        return tool.Blender.Modifier.is_railing(element)
+
+    @classmethod
+    def _get_props(cls, obj: bpy.types.Object):
+        return tool.Model.get_railing_props(obj)
+
+    @classmethod
+    def _post_load_data(cls, data: dict) -> dict:
+        # BIMRailingProperties.path_data is a StringProperty holding JSON.
         data["path_data"] = json.dumps(data["path_data"])
+        return data
 
-        # required since we could load pset from .ifc and BIMRailingProperties won't be set
-        props.set_props_kwargs_from_ifc_data(data)
+    @classmethod
+    def _update_pset(cls, element, data: dict) -> None:
+        update_bbim_railing_pset(element, data)
 
-        props.is_editing = True
-        return {"FINISHED"}
+    @classmethod
+    def _update_modifier_ifc_data(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
+        update_railing_modifier_ifc_data(context)
 
-
-class CancelEditingRailing(bpy.types.Operator, tool.Ifc.Operator):
-    bl_idname = "bim.cancel_editing_railing"
-    bl_label = "Cancel Editing Railing"
-    bl_options = {"REGISTER"}
-
-    def _execute(self, context):
-        obj = context.active_object
-        assert obj
-        data = tool.Model.get_modeling_bbim_pset_data(obj, "BBIM_Railing")["data_dict"]
-        props = tool.Model.get_railing_props(obj)
-
-        # restore previous settings since editing was canceled
-        props.set_props_kwargs_from_ifc_data(data)
+    @classmethod
+    def _update_modifier_bmesh(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
         update_railing_modifier_bmesh(context)
 
-        props.is_editing = False
-        return {"FINISHED"}
 
-
-class FinishEditingRailing(bpy.types.Operator, tool.Ifc.Operator):
-    bl_idname = "bim.finish_editing_railing"
-    bl_label = "Finish Editing Railing"
-    bl_options = {"REGISTER"}
+class EnableEditingRailing(_RailingEditMixin, bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.enable_editing_railing"
+    bl_label = "Enable Editing Railing"
+    bl_options = {"REGISTER", "UNDO"}
 
     def _execute(self, context):
-        obj = context.active_object
-        assert obj
-        element = tool.Ifc.get_entity(obj)
-        assert element
-        props = tool.Model.get_railing_props(obj)
+        return self._enable_targets(context)
 
-        pset_data = tool.Model.get_modeling_bbim_pset_data(bpy.context.active_object, "BBIM_Railing")
-        path_data = pset_data["data_dict"]["path_data"]
 
-        railing_data = props.get_general_kwargs(convert_to_project_units=True)
-        railing_data["path_data"] = path_data
-        props.is_editing = False
+class CancelEditingRailing(_RailingEditMixin, bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.cancel_editing_railing"
+    bl_label = "Cancel Editing Railing"
+    bl_options = {"REGISTER", "UNDO"}
 
-        update_bbim_railing_pset(element, railing_data)
-        update_railing_modifier_ifc_data(context)
-        return {"FINISHED"}
+    def _execute(self, context):
+        return self._cancel_targets(context)
+
+
+class FinishEditingRailing(_RailingEditMixin, bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.finish_editing_railing"
+    bl_label = "Finish Editing Railing"
+    bl_options = {"REGISTER", "UNDO"}
+
+    def _execute(self, context):
+        return self._finish_targets(context)
 
 
 class FlipRailingPathOrder(bpy.types.Operator, tool.Ifc.Operator):

src/bonsai/bonsai/bim/module/model/roof.py

@@ -34,6 +34,7 @@ import bonsai.core.root
 import bonsai.tool as tool
 from bonsai.bim.module.model.data import RoofData, refresh
 from bonsai.bim.module.model.decorator import ProfileDecorator
+from bonsai.bim.parametric_lifecycle import PathPreservingEditMixin
 
 # reference:
 # https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcRoof.htm
@@ -608,61 +609,59 @@ class AddRoof(bpy.types.Operator, tool.Ifc.Operator):
         tool.Model.add_body_representation(obj)
 
 
-class EnableEditingRoof(bpy.types.Operator, tool.Ifc.Operator):
-    bl_idname = "bim.enable_editing_roof"
-    bl_label = "Enable Editing Roof"
-    bl_options = {"REGISTER"}
+class _RoofEditMixin(PathPreservingEditMixin):
+    """Type-specific hooks for roof parametric-edit operators. Single-object
+    (active_object). ``path_data`` is preserved through the edit; the separate
+    ``Enable/Finish/CancelEditingRoofPath`` operators handle path editing."""
 
-    def _execute(self, context):
-        obj = context.active_object
-        assert obj
-        props = tool.Model.get_roof_props(obj)
-        data = tool.Model.get_modeling_bbim_pset_data(obj, "BBIM_Roof")["data_dict"]
-        # required since we could load pset from .ifc and BIMRoofProperties won't be set
-        props.set_props_kwargs_from_ifc_data(data)
-        props.is_editing = True
-        return {"FINISHED"}
+    pset_name = "BBIM_Roof"
 
+    @classmethod
+    def _is_element_type(cls, element):
+        return tool.Blender.Modifier.is_roof(element)
 
-class CancelEditingRoof(bpy.types.Operator, tool.Ifc.Operator):
-    bl_idname = "bim.cancel_editing_roof"
-    bl_label = "Cancel Editing Roof"
-    bl_options = {"REGISTER"}
+    @classmethod
+    def _get_props(cls, obj: bpy.types.Object):
+        return tool.Model.get_roof_props(obj)
 
-    def _execute(self, context):
-        obj = context.active_object
-        assert obj
-        data = tool.Model.get_modeling_bbim_pset_data(obj, "BBIM_Roof")["data_dict"]
-        props = tool.Model.get_roof_props(obj)
+    @classmethod
+    def _update_pset(cls, element, data: dict) -> None:
+        update_bbim_roof_pset(element, data)
 
-        # restore previous settings since editing was canceled
-        props.set_props_kwargs_from_ifc_data(data)
+    @classmethod
+    def _update_modifier_ifc_data(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
+        update_roof_modifier_ifc_data(context)
+
+    @classmethod
+    def _update_modifier_bmesh(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
         update_roof_modifier_bmesh(obj)
 
-        props.is_editing = False
-        return {"FINISHED"}
 
-
-class FinishEditingRoof(bpy.types.Operator, tool.Ifc.Operator):
-    bl_idname = "bim.finish_editing_roof"
-    bl_label = "Finish Editing Roof"
-    bl_options = {"REGISTER"}
+class EnableEditingRoof(_RoofEditMixin, bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.enable_editing_roof"
+    bl_label = "Enable Editing Roof"
+    bl_options = {"REGISTER", "UNDO"}
 
     def _execute(self, context):
-        obj = context.active_object
-        element = tool.Ifc.get_entity(obj)
-        props = tool.Model.get_roof_props(obj)
+        return self._enable_targets(context)
 
-        pset_data = tool.Model.get_modeling_bbim_pset_data(obj, "BBIM_Roof")
-        path_data = pset_data["data_dict"]["path_data"]
 
-        roof_data = props.get_general_kwargs(convert_to_project_units=True)
-        roof_data["path_data"] = path_data
-        props.is_editing = False
+class CancelEditingRoof(_RoofEditMixin, bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.cancel_editing_roof"
+    bl_label = "Cancel Editing Roof"
+    bl_options = {"REGISTER", "UNDO"}
 
-        update_bbim_roof_pset(element, roof_data)
-        update_roof_modifier_ifc_data(context)
-        return {"FINISHED"}
+    def _execute(self, context):
+        return self._cancel_targets(context)
+
+
+class FinishEditingRoof(_RoofEditMixin, bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.finish_editing_roof"
+    bl_label = "Finish Editing Roof"
+    bl_options = {"REGISTER", "UNDO"}
+
+    def _execute(self, context):
+        return self._finish_targets(context)
 
 
 class EnableEditingRoofPath(bpy.types.Operator, tool.Ifc.Operator):

src/bonsai/bonsai/bim/module/model/stair.py

@@ -15,6 +15,8 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 import json
 
@@ -262,7 +264,6 @@ class FinishEditingStair(bpy.types.Operator, tool.Ifc.Operator):
 
         # Use the special method that includes custom_tread_lock for IFC storage
         data = props.get_props_kwargs_for_ifc_export(convert_to_project_units=True)
-        props.is_editing = False
         regenerate_stair_mesh(obj)
         tool.Model.add_body_representation(obj)
 
@@ -272,6 +273,7 @@ class FinishEditingStair(bpy.types.Operator, tool.Ifc.Operator):
 
         # update IfcStairFlight properties
         update_ifc_stair_props(obj)
+        props.is_editing = False
         return {"FINISHED"}
 
 
@@ -608,29 +610,23 @@ class GizmoStairEdition(bpy.types.GizmoGroup, gizmo.BaseParametricGizmoGroup):
             "VIEW3D_GT_minus", self.COLOR_RED, "bim.adjust_stair_treads", increment=-1
         )
 
-    def _refresh_element_specific(self, context: bpy.types.Context, mw: Matrix, props: "BIMStairProperties") -> None:
-        """Update stair-specific lock and tread count gizmos."""
-        billboard_rot = gizmo.get_billboard_rotation(context)
-        self.update_lock_gizmo(mw, props, billboard_rot)
+    def _refresh_element_specific(
+        self, context: bpy.types.Context, mw: Matrix, props: "BIMStairProperties"  # noqa: ARG002
+    ) -> None:
+        """Update stair-specific lock and tread count gizmos. Lock positioning is
+        handled per-frame in the dimension-positioning hook."""
+        self.update_lock_gizmo(props)
         self.update_tread_lock_gizmo(props)
         self.update_tread_count_gizmos(props)
 
-    def update_lock_gizmo(self, mw: Matrix, props: "BIMStairProperties", billboard_rot: Matrix) -> None:
-        """Update lock gizmo visibility, color, and position."""
+    def update_lock_gizmo(self, props: "BIMStairProperties") -> None:
+        """Update lock gizmo color and visibility. Positioning is handled
+        per-frame by the dimension-positioning hook."""
         gizmo_prefs = self.get_gizmo_prefs()
         if not self.update_gizmo_visibility(self.lock_gizmo, props.is_editing, gizmo_prefs.lock):
-            return  # Hidden, skip positioning
-
+            return  # Hidden, skip color update
         self.lock_gizmo.color = self.COLOR_RED if props.total_length_lock else self.COLOR_GREEN
 
-        total_run = props.get_total_run()
-        local_transform = (
-            Matrix.Translation(Vector((total_run + self.ICON_Z_OFFSET, -self.GIZMO_OFFSET, -self.GIZMO_OFFSET)))
-            @ billboard_rot
-            @ Matrix.Scale(self.EDITING_ICON_SCALE, 4)
-        )
-        self.lock_gizmo.matrix_basis = mw @ local_transform
-
     def update_tread_lock_gizmo(self, props: "BIMStairProperties") -> None:
         """Update visibility of tread lock gizmo. Positioning is handled in _update_editing_icon_positions."""
         if not hasattr(self, "tread_lock_gizmo"):
@@ -650,11 +646,11 @@ class GizmoStairEdition(bpy.types.GizmoGroup, gizmo.BaseParametricGizmoGroup):
         )
 
     def _update_dimension_gizmo_positions(
-        self, context: bpy.types.Context, mw: Matrix, props: "BIMStairProperties"
+        self, context: bpy.types.Context, mw: Matrix, props: "BIMStairProperties"  # noqa: ARG002
     ) -> None:
         """Update dimension gizmo positions based on camera view direction."""
-        viewing_from_negative_y, viewing_from_negative_x = self.get_local_view_direction(context, mw)
-        billboard_rot = gizmo.get_billboard_rotation(context)
+        viewing_from_negative_y, viewing_from_negative_x = self._frame_view_dir
+        billboard_rot = self._frame_billboard_rot
         total_run = props.get_total_run()
         riser_height = props.get_riser_height()
 

src/bonsai/bonsai/bim/module/model/ui.py

@@ -338,6 +338,36 @@ class BIM_PT_stair(bpy.types.Panel):
             row.operator("bim.add_stair", icon="ADD", text="")
 
 
+class BIM_PT_wall(bpy.types.Panel):
+    bl_label = "Wall"
+    bl_idname = "BIM_PT_wall"
+    bl_space_type = "PROPERTIES"
+    bl_region_type = "WINDOW"
+    bl_context = "scene"
+    bl_options = {"DEFAULT_CLOSED"}
+    bl_parent_id = "BIM_PT_tab_parametric_geometry"
+
+    @classmethod
+    def poll(cls, context):
+        obj = context.active_object
+        if not obj:
+            return False
+        element = tool.Ifc.get_entity(obj)
+        return bool(element) and tool.Blender.Modifier.is_wall(element)
+
+    def draw(self, context):
+        obj = context.active_object
+        if obj is None:
+            return
+        props = tool.Model.get_wall_props(obj)
+        row = self.layout.row(align=True)
+        if props.is_editing:
+            row.operator("bim.finish_editing_wall", icon="CHECKMARK", text="Finish Editing")
+            row.operator("bim.cancel_editing_wall", icon="CANCEL", text="")
+        else:
+            row.operator("bim.enable_editing_wall", icon="GREASEPENCIL", text="Edit Wall")
+
+
 class BIM_PT_sverchok(bpy.types.Panel):
     bl_label = "Sverchok"
     bl_idname = "BIM_PT_sverchok"

src/bonsai/bonsai/bim/module/model/window.py

@@ -39,6 +39,7 @@ import bonsai.core.root
 import bonsai.tool as tool
 from bonsai.bim.module.drawing import gizmos as gizmo
 from bonsai.bim.module.drawing.gizmos import DimensionGizmoConfig
+from bonsai.bim.parametric_lifecycle import FeatureModifierEditMixin
 
 if TYPE_CHECKING:
     from bonsai.bim.module.model.prop import BIMWindowProperties
@@ -482,90 +483,53 @@ class AddWindow(bpy.types.Operator, tool.Ifc.Operator):
         return {"FINISHED"}
 
 
-class CancelEditingWindow(bpy.types.Operator, tool.Ifc.Operator):
+class _WindowEditMixin(FeatureModifierEditMixin):
+    """Type-specific hooks for window parametric-edit operators. Single-object
+    by design (window edits target the active object only)."""
+
+    pset_name = "BBIM_Window"
+
+    @classmethod
+    def _is_element_type(cls, element):
+        return tool.Blender.Modifier.is_window(element)
+
+    @classmethod
+    def _get_props(cls, obj: bpy.types.Object):
+        return tool.Model.get_window_props(obj)
+
+    @classmethod
+    def _update_modifier_representation(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
+        update_window_modifier_representation(context)
+
+
+class CancelEditingWindow(_WindowEditMixin, bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.cancel_editing_window"
     bl_label = "Cancel Editing Window"
     bl_description = "Cancel editing and revert window parameters to their previous values"
-    bl_options = {"REGISTER"}
+    bl_options = {"REGISTER", "UNDO"}
 
     def _execute(self, context: bpy.types.Context) -> set[str]:
-        obj = context.active_object
-        assert obj
-        element = tool.Ifc.get_entity(obj)
-        assert element
-        data = json.loads(ifcopenshell.util.element.get_pset(element, "BBIM_Window", "Data"))
-        data.update(data.pop("lining_properties"))
-        data.update(data.pop("panel_properties"))
-        props = tool.Model.get_window_props(obj)
-        props.set_props_kwargs_from_ifc_data(data)
-
-        body = ifcopenshell.util.representation.get_representation(element, "Model", "Body", "MODEL_VIEW")
-        bonsai.core.geometry.switch_representation(
-            tool.Ifc,
-            tool.Geometry,
-            obj=obj,
-            representation=body,
-        )
-
-        props.is_editing = False
-        return {"FINISHED"}
+        return self._cancel_targets(context)
 
 
-class FinishEditingWindow(bpy.types.Operator, tool.Ifc.Operator):
+class FinishEditingWindow(_WindowEditMixin, bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.finish_editing_window"
     bl_label = "Finish Editing Window"
     bl_description = "Apply changes and finish editing window parameters"
-    bl_options = {"REGISTER"}
+    bl_options = {"REGISTER", "UNDO"}
 
     def _execute(self, context: bpy.types.Context) -> set[str]:
-        obj = context.active_object
-        assert obj
-        element = tool.Ifc.get_entity(obj)
-        assert element
-        props = tool.Model.get_window_props(obj)
-
-        window_data = props.get_general_kwargs(convert_to_project_units=True)
-        lining_props = props.get_lining_kwargs(convert_to_project_units=True)
-        panel_props = props.get_panel_kwargs(convert_to_project_units=True)
-
-        window_data["lining_properties"] = lining_props
-        window_data["panel_properties"] = panel_props
-
-        props.is_editing = False
-
-        update_window_modifier_representation(context)
-        element_type = ifcopenshell.util.element.get_type(element)
-        if element_type:
-            tool.Model.mark_thumbnail_for_update(element_type)
-
-        pset = tool.Pset.get_element_pset(element, "BBIM_Window")
-        window_data = tool.Ifc.get().createIfcText(json.dumps(window_data, default=list))
-        ifcopenshell.api.pset.edit_pset(tool.Ifc.get(), pset=pset, properties={"Data": window_data})
-        return {"FINISHED"}
+        return self._finish_targets(context)
 
 
-class EnableEditingWindow(bpy.types.Operator, tool.Ifc.Operator):
+class EnableEditingWindow(_WindowEditMixin, bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.enable_editing_window"
     bl_label = "Enable Editing Window"
     bl_description = "Enter edit mode to modify window parameters interactively"
-    bl_options = {"REGISTER"}
+    bl_options = {"REGISTER", "UNDO"}
 
     def _execute(self, context: bpy.types.Context) -> set[str]:
-        obj = context.active_object
-        assert obj
-        props = tool.Model.get_window_props(obj)
-        element = tool.Ifc.get_entity(obj)
-        assert element
-        data = json.loads(ifcopenshell.util.element.get_pset(element, "BBIM_Window", "Data"))
-        data.update(data.pop("lining_properties"))
-        data.update(data.pop("panel_properties"))
-        data.update(tool.Model.get_constituents_props_data(element))
-
-        # required since we could load pset from .ifc and BIMWindowProperties won't be set
-        props.set_props_kwargs_from_ifc_data(data)
-
-        props.is_editing = True
-        return {"FINISHED"}
+        return self._enable_targets(context)
 
 
 class RemoveWindow(bpy.types.Operator, tool.Ifc.Operator):

src/bonsai/bonsai/bim/module/model/workspace.py

@@ -841,7 +841,7 @@ class EditObjectUI:
         row = cls.layout.row(align=True)
         row.separator()
         row.label(text="Operations") if ui_context != "TOOL_HEADER" else row
-        cls.draw_regen_operations(row)
+        cls.draw_regen_operations(row, ui_context)
 
         if AuthoringData.data["active_material_usage"] == "LAYER2":
             row = cls.layout.row(align=True) if ui_context != "TOOL_HEADER" else row
@@ -962,20 +962,14 @@ class EditObjectUI:
         return row
 
     @classmethod
-    def draw_regen_operations(cls, row):
-        custom_icon = custom_icon_previews.get("REGEN", custom_icon_previews["IFC"]).icon_id
-
+    def draw_regen_operations(cls, row, ui_context):
         if AuthoringData.data["is_regenable_element"]:
-            op = row.operator("bim.hotkey", text="", icon_value=custom_icon)
-            description = "Recalculate Element Geometry\nHotkey: S G"
-            op.hotkey = "S_G"
-            op.description = description.strip()
+            row = cls.layout.row(align=True) if ui_context != "TOOL_HEADER" else row
+            add_layout_hotkey_operator(row, "Regen", "S_G", "Recalculate Element Geometry", ui_context)
 
         if PortData.data["total_ports"] > 0:
-            op = row.operator("bim.hotkey", text="", icon_value=custom_icon)
-            description = f"{bpy.ops.bim.regenerate_distribution_element.__doc__}\n\nHotkey: S G"
-            op.hotkey = "S_G"
-            op.description = description.strip()
+            row = cls.layout.row(align=True) if ui_context != "TOOL_HEADER" else row
+            add_layout_hotkey_operator(row, "Regen", "S_G", bpy.ops.bim.regenerate_distribution_element.__doc__, ui_context)
 
     @classmethod
     def draw_void(cls, context, row):

src/bonsai/bonsai/bim/module/nest/decorator.py

@@ -101,7 +101,7 @@ class NestDecorator:
         cls.is_installed = False
 
     def dotted_line_shader(self):
-        vert_out = gpu.types.GPUStageInterfaceInfo("my_interface")  # ty:ignore[too-many-positional-arguments]
+        vert_out = gpu.types.GPUStageInterfaceInfo("my_interface")
         vert_out.smooth("FLOAT", "v_ArcLength")
 
         shader_info = gpu.types.GPUShaderCreateInfo()

src/bonsai/bonsai/bim/module/owner/operator.py

@@ -33,7 +33,7 @@ class EnableEditingPerson(bpy.types.Operator):
     bl_idname = "bim.enable_editing_person"
     bl_label = "Enable Editing Person"
     bl_options = {"REGISTER", "UNDO"}
-    person: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    person: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         person: int
@@ -75,7 +75,7 @@ class RemovePerson(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_person"
     bl_label = "Remove Person"
     bl_options = {"REGISTER", "UNDO"}
-    person: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    person: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         person: int
@@ -88,7 +88,7 @@ class AddPersonAttribute(bpy.types.Operator):
     bl_idname = "bim.add_person_attribute"
     bl_label = "Add Person Attribute"
     bl_options = {"REGISTER", "UNDO"}
-    name: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    name: bpy.props.EnumProperty(
         items=tuple((i, i, "") for i in get_args(tool.Owner.PersonAttributeType)),
     )
 
@@ -104,10 +104,10 @@ class RemovePersonAttribute(bpy.types.Operator):
     bl_idname = "bim.remove_person_attribute"
     bl_label = "Remove Person Attribute"
     bl_options = {"REGISTER", "UNDO"}
-    name: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    name: bpy.props.EnumProperty(
         items=tuple((i, i, "") for i in get_args(tool.Owner.PersonAttributeType)),
     )
-    id: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    id: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         name: tool.Owner.PersonAttributeType  # pyright: ignore[reportIncompatibleVariableOverride]
@@ -122,7 +122,7 @@ class EnableEditingRole(bpy.types.Operator):
     bl_idname = "bim.enable_editing_role"
     bl_label = "Enable Editing Role"
     bl_options = {"REGISTER", "UNDO"}
-    role: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    role: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         role: int
@@ -146,7 +146,7 @@ class AddRole(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_role"
     bl_label = "Add Role"
     bl_options = {"REGISTER", "UNDO"}
-    parent: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    parent: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         parent: int
@@ -168,7 +168,7 @@ class RemoveRole(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_role"
     bl_label = "Remove Role"
     bl_options = {"REGISTER", "UNDO"}
-    role: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    role: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         role: int
@@ -181,8 +181,8 @@ class AddAddress(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_address"
     bl_label = "Add Address"
     bl_options = {"REGISTER", "UNDO"}
-    parent: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
-    ifc_class: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    parent: bpy.props.IntProperty()
+    ifc_class: bpy.props.EnumProperty(
         items=tuple((i, i, "") for i in get_args(ADDRESS_TYPE)),
     )
 
@@ -198,7 +198,7 @@ class AddAddressAttribute(bpy.types.Operator):
     bl_idname = "bim.add_address_attribute"
     bl_label = "Add Address Attribute"
     bl_options = {"REGISTER", "UNDO"}
-    name: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    name: bpy.props.EnumProperty(
         items=tuple((i, i, "") for i in get_args(tool.Owner.AddressAttributeType)),
     )
 
@@ -214,10 +214,10 @@ class RemoveAddressAttribute(bpy.types.Operator):
     bl_idname = "bim.remove_address_attribute"
     bl_label = "Remove Address Attribute"
     bl_options = {"REGISTER", "UNDO"}
-    name: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    name: bpy.props.EnumProperty(
         items=tuple((i, i, "") for i in get_args(tool.Owner.AddressAttributeType)),
     )
-    id: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    id: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         name: tool.Owner.AddressAttributeType  # pyright: ignore[reportIncompatibleVariableOverride]
@@ -232,7 +232,7 @@ class EnableEditingAddress(bpy.types.Operator):
     bl_idname = "bim.enable_editing_address"
     bl_label = "Enable Editing Address"
     bl_options = {"REGISTER", "UNDO"}
-    address: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    address: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         address: int
@@ -265,7 +265,7 @@ class RemoveAddress(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_address"
     bl_label = "Remove Address"
     bl_options = {"REGISTER", "UNDO"}
-    address: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    address: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         address: int
@@ -278,7 +278,7 @@ class EnableEditingOrganisation(bpy.types.Operator):
     bl_idname = "bim.enable_editing_organisation"
     bl_label = "Enable Editing Organisation"
     bl_options = {"REGISTER", "UNDO"}
-    organisation: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    organisation: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         organisation: int
@@ -320,7 +320,7 @@ class RemoveOrganisation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_organisation"
     bl_label = "Remove Organisation"
     bl_options = {"REGISTER", "UNDO"}
-    organisation: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    organisation: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         organisation: int
@@ -333,8 +333,8 @@ class AddPersonAndOrganisation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_person_and_organisation"
     bl_label = "Add Person And Organisation"
     bl_options = {"REGISTER", "UNDO"}
-    person: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
-    organisation: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    person: bpy.props.IntProperty()
+    organisation: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         person: int
@@ -350,7 +350,7 @@ class RemovePersonAndOrganisation(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_person_and_organisation"
     bl_label = "Remove Person And Organisation"
     bl_options = {"REGISTER", "UNDO"}
-    person_and_organisation: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    person_and_organisation: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         person_and_organisation: int
@@ -365,7 +365,7 @@ class SetUser(bpy.types.Operator):
     bl_idname = "bim.set_user"
     bl_label = "Set User"
     bl_options = {"REGISTER", "UNDO"}
-    user: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    user: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         user: int
@@ -401,7 +401,7 @@ class EnableEditingActor(bpy.types.Operator):
     bl_idname = "bim.enable_editing_actor"
     bl_label = "Enable Editing Actor"
     bl_options = {"REGISTER", "UNDO"}
-    actor: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    actor: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         actor: int
@@ -434,7 +434,7 @@ class RemoveActor(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_actor"
     bl_label = "Remove Actor"
     bl_options = {"REGISTER", "UNDO"}
-    actor: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    actor: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         actor: int
@@ -447,7 +447,7 @@ class AssignActor(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_actor"
     bl_label = "Assign Actor"
     bl_options = {"REGISTER", "UNDO"}
-    actor: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    actor: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         actor: int
@@ -462,7 +462,7 @@ class UnassignActor(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.unassign_actor"
     bl_label = "Unassign Actor"
     bl_options = {"REGISTER", "UNDO"}
-    actor: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    actor: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         actor: int
@@ -481,7 +481,7 @@ class RemoveApplication(bpy.types.Operator, tool.Ifc.Operator):
         "Remove provided IfcApplication."
         "\n\nFor safety will only work on applications without inverses (they are typically marked as '(unused)'."
     )
-    application_id: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    application_id: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         application_id: int
@@ -525,7 +525,7 @@ class EnableEditingApplication(bpy.types.Operator):
     bl_idname = "bim.enable_editing_application"
     bl_label = "Enable Editing Application"
     bl_options = {"REGISTER", "UNDO"}
-    application_id: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    application_id: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         application_id: int

src/bonsai/bonsai/bim/module/project/operator.py

@@ -15,6 +15,8 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 import datetime
 import json
@@ -86,9 +88,7 @@ class NewProject(bpy.types.Operator):
     bl_label = "New Project"
     bl_options = {"REGISTER", "UNDO"}
     bl_description = "Start a new IFC project in a fresh session"
-    preset: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
-        items=[(i, i, "") for i in get_args(PresetType)]
-    )
+    preset: bpy.props.EnumProperty(items=[(i, i, "") for i in get_args(PresetType)])
 
     if TYPE_CHECKING:
         preset: PresetType
@@ -178,13 +178,9 @@ class SelectLibraryFile(bpy.types.Operator, IFCFileSelector, ImportHelper):
     bl_description = (
         "Select an IFC file that can be used as a library.\n\nALT+click to reload the current loaded library file."
     )
-    filter_glob: bpy.props.StringProperty(
-        default="*.ifc;*.ifczip;*.ifcxml", options={"HIDDEN"}
-    )  # pyright: ignore[reportRedeclaration]
-    append_all: bpy.props.BoolProperty(default=False)  # pyright: ignore[reportRedeclaration]
-    use_relative_path: bpy.props.BoolProperty(
-        name="Use Relative Path", default=False
-    )  # pyright: ignore[reportRedeclaration]
+    filter_glob: bpy.props.StringProperty(default="*.ifc;*.ifczip;*.ifcxml", options={"HIDDEN"})
+    append_all: bpy.props.BoolProperty(default=False)
+    use_relative_path: bpy.props.BoolProperty(name="Use Relative Path", default=False)
 
     if TYPE_CHECKING:
         filter_glob: str
@@ -568,7 +564,7 @@ class AppendLibraryElementByQuery(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.append_library_element_by_query"
     bl_label = "Append Library Element By Query"
 
-    query: bpy.props.StringProperty(name="Query")  # pyright: ignore[reportRedeclaration]
+    query: bpy.props.StringProperty(name="Query")
 
     if TYPE_CHECKING:
         query: str
@@ -600,11 +596,9 @@ class AppendLibraryElement(bpy.types.Operator, tool.Ifc.Operator):
         "Append element to the current project.\n\n"
         "ALT+CLICK to skip reusing materials, profiles, styles based on their name (may result in duplicates)"
     )
-    definition: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
-    prop_index: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
-    assume_unique_by_name: bpy.props.BoolProperty(
-        name="Assume Unique By Name", default=True, options={"SKIP_SAVE"}
-    )  # pyright: ignore[reportRedeclaration]
+    definition: bpy.props.IntProperty()
+    prop_index: bpy.props.IntProperty()
+    assume_unique_by_name: bpy.props.BoolProperty(name="Assume Unique By Name", default=True, options={"SKIP_SAVE"})
 
     if TYPE_CHECKING:
         definition: int
@@ -959,28 +953,24 @@ class LoadProject(bpy.types.Operator, IFCFileSelector, ImportHelper):
     bl_label = "Load Project"
     bl_options = {"REGISTER", "UNDO"}
     bl_description = "Load an existing IFC project"
-    filepath: bpy.props.StringProperty(
-        subtype="FILE_PATH", options={"SKIP_SAVE"}
-    )  # pyright: ignore[reportRedeclaration]
-    filter_glob: bpy.props.StringProperty(
-        default="*.ifc;*.ifczip;*.ifcxml;*.ifcsqlite", options={"HIDDEN"}
-    )  # pyright: ignore[reportRedeclaration]
-    is_advanced: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    filepath: bpy.props.StringProperty(subtype="FILE_PATH", options={"SKIP_SAVE"})
+    filter_glob: bpy.props.StringProperty(default="*.ifc;*.ifczip;*.ifcxml;*.ifcsqlite", options={"HIDDEN"})
+    is_advanced: bpy.props.BoolProperty(
         name="Enable Advanced Mode",
         description="Load IFC file with advanced settings. Checking this option will skip loading IFC file and will open advanced load settings",
         default=False,
     )
-    use_relative_path: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    use_relative_path: bpy.props.BoolProperty(
         name="Use Relative Path",
         description="Store the IFC project path relative to the .blend file. Requires .blend file to be saved",
         default=False,
     )
-    should_start_fresh_session: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    should_start_fresh_session: bpy.props.BoolProperty(
         name="Should Start Fresh Session",
         description="Clear current Blender session before loading IFC. Not supported with 'Use Relative Path' option",
         default=True,
     )
-    import_without_ifc_data: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    import_without_ifc_data: bpy.props.BoolProperty(
         name="Import Without IFC Data",
         description=(
             "Import IFC objects as Blender objects without any IFC metadata and authoring capabilities."
@@ -988,9 +978,7 @@ class LoadProject(bpy.types.Operator, IFCFileSelector, ImportHelper):
         ),
         default=False,
     )
-    use_detailed_tooltip: bpy.props.BoolProperty(
-        default=False, options={"HIDDEN"}
-    )  # pyright: ignore[reportRedeclaration]
+    use_detailed_tooltip: bpy.props.BoolProperty(default=False, options={"HIDDEN"})
     filename_ext = ".ifc"
 
     if TYPE_CHECKING:
@@ -1300,7 +1288,7 @@ class ToggleFilterCategories(bpy.types.Operator):
     bl_idname = "bim.toggle_filter_categories"
     bl_label = "Toggle Filter Categories"
     bl_options = {"REGISTER", "UNDO"}
-    should_select: bpy.props.BoolProperty(name="Should Select", default=True)  # pyright: ignore[reportRedeclaration]
+    should_select: bpy.props.BoolProperty(name="Should Select", default=True)
 
     if TYPE_CHECKING:
         should_select: bool
@@ -1327,7 +1315,7 @@ class LinkIfc(bpy.types.Operator, ImportHelper, tool.Ifc.Operator):
         default=False,
     )
     use_cache: bpy.props.BoolProperty(name="Use Cache", default=True)
-    query: bpy.props.StringProperty(  # pyright: ignore[reportRedeclaration]
+    query: bpy.props.StringProperty(
         name="Query",
         description=(
             "Custom selector query to use to load element from a linked model. E.g. 'IfcElement'.\n\n"
@@ -1404,7 +1392,7 @@ class UnlinkIfc(bpy.types.Operator, tool.Ifc.Operator):
     bl_options = {"REGISTER", "UNDO"}
     bl_description = "Remove the selected file from the link list"
 
-    link_index: bpy.props.IntProperty(name="Link Index")  # pyright: ignore[reportRedeclaration]
+    link_index: bpy.props.IntProperty(name="Link Index")
 
     if TYPE_CHECKING:
         link_index: int
@@ -1428,7 +1416,7 @@ class UnloadLink(bpy.types.Operator, tool.Ifc.Operator):
     bl_options = {"REGISTER", "UNDO"}
     bl_description = "Unload the selected linked file"
 
-    link_index: bpy.props.IntProperty(name="Link Index")  # pyright: ignore[reportRedeclaration]
+    link_index: bpy.props.IntProperty(name="Link Index")
 
     if TYPE_CHECKING:
         link_index: int
@@ -1454,9 +1442,9 @@ class LoadLink(bpy.types.Operator, tool.Ifc.Operator):
     bl_options = {"REGISTER", "UNDO"}
     bl_description = "Load the selected file"
 
-    link_index: bpy.props.IntProperty(name="Link Index")  # pyright: ignore[reportRedeclaration]
-    use_cache: bpy.props.BoolProperty(name="Use Cache", default=True)  # pyright: ignore[reportRedeclaration]
-    query: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    link_index: bpy.props.IntProperty(name="Link Index")
+    use_cache: bpy.props.BoolProperty(name="Use Cache", default=True)
+    query: bpy.props.StringProperty()
 
     if TYPE_CHECKING:
         link_index: int
@@ -1631,7 +1619,7 @@ class ReloadLink(bpy.types.Operator):
     bl_options = {"REGISTER", "UNDO"}
     bl_description = "Reload the selected file"
 
-    link_index: bpy.props.IntProperty(name="Link Index")  # pyright: ignore[reportRedeclaration]
+    link_index: bpy.props.IntProperty(name="Link Index")
 
     if TYPE_CHECKING:
         link_index: int
@@ -1647,7 +1635,7 @@ class ToggleLinkSelectability(bpy.types.Operator):
     bl_options = {"REGISTER", "UNDO"}
     bl_description = "Toggle selectability"
 
-    link_index: bpy.props.IntProperty(name="Link Index")  # pyright: ignore[reportRedeclaration]
+    link_index: bpy.props.IntProperty(name="Link Index")
 
     if TYPE_CHECKING:
         link_index: int
@@ -1679,8 +1667,8 @@ class ToggleLinkVisibility(bpy.types.Operator):
     bl_options = {"REGISTER", "UNDO"}
     bl_description = "Toggle visibility between SOLID and WIREFRAME"
 
-    link_index: bpy.props.IntProperty(name="Link Index")  # pyright: ignore[reportRedeclaration]
-    mode: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    link_index: bpy.props.IntProperty(name="Link Index")
+    mode: bpy.props.EnumProperty(
         name="Visibility Mode",
         items=((i, i, "") for i in ("WIREFRAME", "VISIBLE")),
     )
@@ -1821,7 +1809,7 @@ class SelectLinkHandle(bpy.types.Operator):
     bl_options = {"REGISTER", "UNDO"}
     bl_description = "Select link empty object handle"
 
-    link_index: bpy.props.IntProperty(name="Link Index")  # pyright: ignore[reportRedeclaration]
+    link_index: bpy.props.IntProperty(name="Link Index")
 
     if TYPE_CHECKING:
         link_index: int
@@ -1843,7 +1831,7 @@ class SelectLinkedModelElement(bpy.types.Operator):
     bl_options = {"REGISTER"}
     bl_description = "Select an element in the currently selected linked model by providing GlobalId."
 
-    guid: bpy.props.StringProperty(name="GlobalId")  # pyright: ignore[reportRedeclaration]
+    guid: bpy.props.StringProperty(name="GlobalId")
 
     if TYPE_CHECKING:
         guid: str
@@ -1882,21 +1870,11 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
     bl_options = {"REGISTER", "UNDO"}
     filename_ext = ".ifc"
     supported_filexts = (".ifc", ".ifczip", ".ifcjson")
-    filter_glob: bpy.props.StringProperty(
-        default=";".join(f"*{ext}" for ext in supported_filexts), options={"HIDDEN"}
-    )  # pyright: ignore[reportRedeclaration]
-    json_version: bpy.props.EnumProperty(
-        items=[("4", "4", ""), ("5a", "5a", "")], name="IFC JSON Version"
-    )  # pyright: ignore[reportRedeclaration]
-    json_compact: bpy.props.BoolProperty(
-        name="Export Compact IFCJSON", default=False
-    )  # pyright: ignore[reportRedeclaration]
-    should_save_as: bpy.props.BoolProperty(
-        name="Should Save As", default=False, options={"HIDDEN"}
-    )  # pyright: ignore[reportRedeclaration]
-    use_relative_path: bpy.props.BoolProperty(
-        name="Use Relative Path", default=False
-    )  # pyright: ignore[reportRedeclaration]
+    filter_glob: bpy.props.StringProperty(default=";".join(f"*{ext}" for ext in supported_filexts), options={"HIDDEN"})
+    json_version: bpy.props.EnumProperty(items=[("4", "4", ""), ("5a", "5a", "")], name="IFC JSON Version")
+    json_compact: bpy.props.BoolProperty(name="Export Compact IFCJSON", default=False)
+    should_save_as: bpy.props.BoolProperty(name="Should Save As", default=False, options={"HIDDEN"})
+    use_relative_path: bpy.props.BoolProperty(name="Use Relative Path", default=False)
 
     if TYPE_CHECKING:
         filter_glob: str
@@ -1927,11 +1905,11 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
 
         self.use_relative_path = tool.Project.get_project_props().use_relative_project_path
         props = tool.Blender.get_bim_props()
-        if (filepath := props.ifc_file) and not self.should_save_as:
-            self.filepath = str(tool.Blender.ensure_blender_path_is_abs(Path(filepath)))
-            return self.execute(context)
-
-        return ExportHelper.invoke(self, context, event)
+        filepath = props.ifc_file
+        if not filepath or self.should_save_as:
+            return ExportHelper.invoke(self, context, event)
+        self.filepath = str(tool.Blender.ensure_blender_path_is_abs(Path(filepath)))
+        return self.execute(context)
 
     def check(self, context):
         # ExportHelper is automatically adjusting suffix to `filename_ext`.
@@ -1957,6 +1935,16 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
         return {"FINISHED"}
 
     def _execute(self, context):
+        committed, failed_commits = tool.Parametric.commit_pending_edits()
+        # Suffix is appended to the IFC save-success report below so the auto-commit
+        # info isn't immediately overwritten by the success message in Blender's
+        # status bar (only the latest self.report({"INFO"}, ...) sticks).
+        commit_suffix = f" (auto-committed {committed} pending parametric edit(s))" if committed else ""
+        if failed_commits:
+            names = ", ".join(o.name for o in failed_commits)
+            msg = f"Auto-commit failed for {len(failed_commits)} object(s): {names}"
+            print(f"Bonsai: {msg} (their drafts are NOT saved to the IFC file).")
+            self.report({"ERROR"}, msg)
         start = time.time()
         logger = logging.getLogger("ExportIFC")
         path_log = tool.Blender.get_data_dir_path("process.log")
@@ -2025,7 +2013,7 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
                     blendmetadata_path = output_file + suffix
                 self.report(
                     {"INFO"},
-                    f'IFC Project "{os.path.basename(output_file)}" And Metadata File Saved to: {os.path.basename(blendmetadata_path)}',
+                    f'IFC Project "{os.path.basename(output_file)}" And Metadata File Saved to: {os.path.basename(blendmetadata_path)}{commit_suffix}',
                 )
             except Exception as e:
                 self.report({"ERROR"}, f"Failed to save blend metadata file: {e}")
@@ -2035,7 +2023,7 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
                 bpy.ops.wm.save_mainfile(filepath=bpy.data.filepath)
             self.report(
                 {"INFO"},
-                f'IFC Project "{os.path.basename(output_file)}" {"" if not save_blend_file else "And Current Blend File Are"} Saved',
+                f'IFC Project "{os.path.basename(output_file)}" {"" if not save_blend_file else "And Current Blend File Are"} Saved{commit_suffix}',
             )
 
         bonsai.bim.handler.refresh_ui_data()
@@ -2053,7 +2041,7 @@ class LoadLinkedProject(bpy.types.Operator, ImportHelper):
     bl_description = "Operator is used to load a project .cache.blend to then link it to the IFC file."
     bl_options = {"REGISTER", "UNDO"}
 
-    query: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    query: bpy.props.StringProperty()
     """See ``bim.link_ifc``."""
 
     if TYPE_CHECKING:
@@ -2443,8 +2431,8 @@ class HideQueriedLinkedElement(bpy.types.Operator):
     )
     bl_options = {"REGISTER", "UNDO"}
 
-    unhide_all: bpy.props.BoolProperty(options={"SKIP_SAVE"})  # pyright: ignore[reportRedeclaration]
-    hide_all_except: bpy.props.BoolProperty(options={"SKIP_SAVE"})  # pyright: ignore[reportRedeclaration]
+    unhide_all: bpy.props.BoolProperty(options={"SKIP_SAVE"})
+    hide_all_except: bpy.props.BoolProperty(options={"SKIP_SAVE"})
 
     if TYPE_CHECKING:
         unhide_all: bool
@@ -2918,12 +2906,8 @@ class IFCFileHandlerOperator(bpy.types.Operator):
     bl_label = "Import .ifc file"
     bl_options = {"REGISTER", "UNDO", "INTERNAL"}
 
-    directory: bpy.props.StringProperty(
-        subtype="FILE_PATH", options={"SKIP_SAVE", "HIDDEN"}
-    )  # pyright: ignore[reportRedeclaration]
-    files: bpy.props.CollectionProperty(
-        type=bpy.types.OperatorFileListElement, options={"SKIP_SAVE", "HIDDEN"}
-    )  # pyright: ignore[reportRedeclaration]
+    directory: bpy.props.StringProperty(subtype="FILE_PATH", options={"SKIP_SAVE", "HIDDEN"})
+    files: bpy.props.CollectionProperty(type=bpy.types.OperatorFileListElement, options={"SKIP_SAVE", "HIDDEN"})
 
     if TYPE_CHECKING:
         directory: str
@@ -2978,7 +2962,7 @@ class MeasureTool(bpy.types.Operator, PolylineOperator):
     bl_label = "Measure Tool"
     bl_options = {"REGISTER", "UNDO"}
 
-    measure_type: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    measure_type: bpy.props.StringProperty()
 
     if TYPE_CHECKING:
         measure_type: str
@@ -3077,7 +3061,7 @@ class MeasureFaceAreaTool(bpy.types.Operator, PolylineOperator):
     bl_label = "Measure Face Area Tool"
     bl_options = {"REGISTER", "UNDO"}
 
-    measure_type: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    measure_type: bpy.props.StringProperty()
 
     if TYPE_CHECKING:
         measure_type: str
@@ -3379,7 +3363,7 @@ class LoadBlendMetadataAndIFC(bpy.types.Operator):
     bl_idname = "bim.load_blend_metadata_and_ifc"
     bl_label = "Load Blend Metadata and IFC"
     bl_options = {"REGISTER", "UNDO"}
-    filepath: bpy.props.StringProperty(name="IFC File Path", default="")  # pyright: ignore[reportRedeclaration]
+    filepath: bpy.props.StringProperty(name="IFC File Path", default="")
 
     if TYPE_CHECKING:
         filepath: str

src/bonsai/bonsai/bim/module/project/prop.py

@@ -345,7 +345,7 @@ class BIMProjectProperties(PropertyGroup):
         ),
         default=False,
     )
-    should_cache: BoolProperty(  # pyright: ignore[reportRedeclaration]
+    should_cache: BoolProperty(
         name="Cache",
         description=(
             "Cache loaded geometry to .h5 file in your cache directory (see in preferences) "

src/bonsai/bonsai/bim/module/pset/operator.py

@@ -240,7 +240,7 @@ class CopyPropertyToSelection(bpy.types.Operator, tool.Ifc.Operator):
     bl_label = "Copy Property To Selection"
     bl_options = {"REGISTER", "UNDO"}
 
-    name: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    name: bpy.props.StringProperty()
 
     if TYPE_CHECKING:
         name: str
@@ -280,10 +280,10 @@ class BIM_OT_add_property_to_edit(bpy.types.Operator):
     bl_label = "Add Property to Edit"
     bl_idname = "bim.add_property_to_edit"
     bl_options = {"REGISTER", "UNDO"}
-    option: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    option: bpy.props.EnumProperty(
         items=[(t, t, "") for t in tool.Pset.BULK_OPERATION_TYPES],
     )
-    index: bpy.props.IntProperty(default=-1)  # pyright: ignore[reportRedeclaration]
+    index: bpy.props.IntProperty(default=-1)
 
     if TYPE_CHECKING:
         option: tool.Pset.BulkOperationType
@@ -307,9 +307,9 @@ class BIM_OT_remove_property_to_edit(bpy.types.Operator):
     bl_label = "Remove Property from Editing"
     bl_idname = "bim.remove_property_to_edit"
     bl_options = {"REGISTER", "UNDO"}
-    index: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
-    index2: bpy.props.IntProperty(default=-1)  # pyright: ignore[reportRedeclaration]
-    option: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    index: bpy.props.IntProperty()
+    index2: bpy.props.IntProperty(default=-1)
+    option: bpy.props.EnumProperty(
         items=[(t, t, "") for t in tool.Pset.BULK_OPERATION_TYPES],
     )
 
@@ -336,7 +336,7 @@ class BIM_OT_bulk_edit_clear_list(bpy.types.Operator):
     bl_label = "Clear List of Properties"
     bl_idname = "bim.pset_bulk_edit_clear_list"
     bl_options = {"REGISTER", "UNDO"}
-    option: bpy.props.EnumProperty(  # pyright: ignore[reportRedeclaration]
+    option: bpy.props.EnumProperty(
         items=[(t, t, "") for t in tool.Pset.BULK_OPERATION_TYPES],
     )
 

src/bonsai/bonsai/bim/module/pset/prop.py

@@ -368,9 +368,9 @@ class GlobalPsetProperties(PropertyGroup):
     qto_filter: StringProperty(name="Qto Filter", options={"TEXTEDIT_UPDATE"})
 
     # Bulk operations.
-    psets_to_delete: CollectionProperty(type=DeletePsetEntry)  # pyright: ignore[reportRedeclaration]
-    psets_to_rename: CollectionProperty(type=RenamePropertyEntry)  # pyright: ignore[reportRedeclaration]
-    psets_to_add_edit: CollectionProperty(type=AddEditPropertyEntry)  # pyright: ignore[reportRedeclaration]
+    psets_to_delete: CollectionProperty(type=DeletePsetEntry)
+    psets_to_rename: CollectionProperty(type=RenamePropertyEntry)
+    psets_to_add_edit: CollectionProperty(type=AddEditPropertyEntry)
 
     if TYPE_CHECKING:
         pset_filter: str

src/bonsai/bonsai/bim/module/search/operator.py

@@ -799,7 +799,7 @@ class SelectQueryElements(Operator):
     bl_description = "Select elements matching an provided selector query"
     bl_options = {"REGISTER", "UNDO"}
 
-    query: StringProperty(name="Query")  # pyright: ignore[reportRedeclaration]
+    query: StringProperty(name="Query")
 
     if TYPE_CHECKING:
         query: str
@@ -829,12 +829,12 @@ class SaveSearch(Operator, tool.Ifc.Operator):
         # Extra item so it will be easy to select current text.
         return [text] + SaveSearch.name_search_items
 
-    name: StringProperty(  # pyright: ignore[reportRedeclaration]
+    name: StringProperty(
         name="Name",
         search=get_name_search_items,
         search_options={"SORT"},
     )
-    module: StringProperty()  # pyright: ignore[reportRedeclaration]
+    module: StringProperty()
 
     def update_use_all_ifcgroups(self, context: object = None) -> None:
         ifc_file = tool.Ifc.get()
@@ -845,7 +845,7 @@ class SaveSearch(Operator, tool.Ifc.Operator):
         }
         self.name_search_items[:] = natsorted(groups)
 
-    use_all_ifcgroups: BoolProperty(  # pyright: ignore[reportRedeclaration]
+    use_all_ifcgroups: BoolProperty(
         name="Use Any IfcGroup",
         description=(
             "By default we're targeting only IfcGroups with SEARCH ObjectType "

src/bonsai/bonsai/bim/module/sequence/operator.py

@@ -106,7 +106,7 @@ class ActivateStatusFilters(bpy.types.Operator):
     bl_description = "Filter and display objects based on currently selected IFC statuses"
     bl_options = {"REGISTER", "UNDO"}
 
-    only_if_enabled: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    only_if_enabled: bpy.props.BoolProperty(
         name="Only If Filters are Enabled",
         description="Activate status filters only in case if they were enabled from the UI before.",
         default=False,
@@ -137,7 +137,7 @@ class SelectStatusFilter(bpy.types.Operator):
     bl_description = "Select elements with currently selected status"
     bl_options = {"REGISTER", "UNDO"}
 
-    status: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    status: bpy.props.StringProperty()
 
     if TYPE_CHECKING:
         status: tool.Sequence.ElementStatusUI
@@ -156,7 +156,7 @@ class AssignStatus(bpy.types.Operator, tool.Ifc.Operator):
     bl_description = "Assign status to the selected elements.\n\nAlt+CLICK to unassign the status."
     bl_options = {"REGISTER", "UNDO"}
 
-    should_override_previous_status: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    should_override_previous_status: bpy.props.BoolProperty(
         name="Override Previous Status",
         description=(
             "Whether assigning new status should override previous one.\n\n"
@@ -165,8 +165,8 @@ class AssignStatus(bpy.types.Operator, tool.Ifc.Operator):
         ),
         default=True,
     )
-    status: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
-    should_unassign_status: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    status: bpy.props.StringProperty()
+    should_unassign_status: bpy.props.BoolProperty(
         options={"SKIP_SAVE"},
     )
 
@@ -415,7 +415,7 @@ class CopyWorkSchedule(bpy.types.Operator, tool.Ifc.Operator):
     bl_label = "Copy Work Schedule"
     bl_description = "Create a duplicate of the provided work schedule."
     bl_options = {"REGISTER", "UNDO"}
-    work_schedule: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    work_schedule: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         work_schedule: int

src/bonsai/bonsai/bim/module/sequence/prop.py

@@ -412,7 +412,7 @@ WorkPlanEditingType = Literal["-", "ATTRIBUTES", "SCHEDULES", "WORK_SCHEDULE", "
 
 class BIMWorkPlanProperties(PropertyGroup):
     work_plan_attributes: CollectionProperty(name="Work Plan Attributes", type=Attribute)
-    editing_type: EnumProperty(  # pyright: ignore[reportRedeclaration]
+    editing_type: EnumProperty(
         items=[(i, i, "") for i in get_args(WorkPlanEditingType)],
     )
     work_plans: CollectionProperty(name="Work Plans", type=WorkPlan)
@@ -430,8 +430,8 @@ class BIMWorkPlanProperties(PropertyGroup):
 
 
 class IFCStatus(PropertyGroup):
-    name: StringProperty()  # pyright: ignore[reportRedeclaration]
-    is_visible: BoolProperty(  # pyright: ignore[reportRedeclaration]
+    name: StringProperty()
+    is_visible: BoolProperty(
         name="Is Visible", default=True, update=lambda x, y: (None, bpy.ops.bim.activate_status_filters())[0]
     )
 

src/bonsai/bonsai/bim/module/spatial/operator.py

@@ -220,7 +220,7 @@ class CopyToContainer(bpy.types.Operator, tool.Ifc.Operator):
     bl_label = "Copy to Container"
     bl_options = {"REGISTER", "UNDO"}
 
-    container: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    container: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         container: int

src/bonsai/bonsai/bim/module/structural/operator.py

@@ -167,7 +167,7 @@ class EnableEditingStructuralBoundaryCondition(bpy.types.Operator):
     bl_idname = "bim.enable_editing_structural_boundary_condition"
     bl_label = "Enable Editing Structural Boundary Condition"
     bl_options = {"REGISTER", "UNDO"}
-    boundary_condition: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    boundary_condition: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         boundary_condition: int
@@ -186,7 +186,7 @@ class EditStructuralBoundaryCondition(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_structural_boundary_condition"
     bl_label = "Edit Structural Boundary Condition"
     bl_options = {"REGISTER", "UNDO"}
-    connection: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    connection: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         connection: int
@@ -917,7 +917,7 @@ class EnableEditingBoundaryCondition(bpy.types.Operator):
     bl_idname = "bim.enable_editing_boundary_condition"
     bl_label = "Enable Editing Boundary Condition"
     bl_options = {"REGISTER", "UNDO"}
-    boundary_condition: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    boundary_condition: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         boundary_condition: int

src/bonsai/bonsai/bim/module/structural/shader.py

@@ -83,7 +83,7 @@ class DecorationShader:
         PARALLEL DISTRIBUTED FORCE,
         DISTRIBUTED MOMENT,
         """
-        vert_out = gpu.types.GPUStageInterfaceInfo("my_interface")  # ty:ignore[too-many-positional-arguments]
+        vert_out = gpu.types.GPUStageInterfaceInfo("my_interface")
         vert_out.smooth("VEC3", "forces")
         vert_out.smooth("VEC3", "co")
 
@@ -203,7 +203,7 @@ class DecorationShader:
         """param: pattern: type of pattern
         SINGLE FORCE,
         SINGLE MOMENT"""
-        vert_out = gpu.types.GPUStageInterfaceInfo("my_interface")  # ty: ignore[too-many-positional-arguments]
+        vert_out = gpu.types.GPUStageInterfaceInfo("my_interface")
         vert_out.smooth("VEC3", "co")
 
         shader_info = gpu.types.GPUShaderCreateInfo()
@@ -253,7 +253,7 @@ class DecorationShader:
 
     def get_planar_shader(self) -> gpu.types.GPUShader:
         """shader for planar loads"""
-        vert_out = gpu.types.GPUStageInterfaceInfo("my_interface")  # ty: ignore[too-many-positional-arguments]
+        vert_out = gpu.types.GPUStageInterfaceInfo("my_interface")
         vert_out.smooth("VEC3", "co")
 
         shader_info = gpu.types.GPUShaderCreateInfo()

src/bonsai/bonsai/bim/module/style/prop.py

@@ -118,6 +118,19 @@ def update_shader_graph(self: Union["Texture", "BIMStylesProperties"], context:
     tool.Loader.create_surface_style_with_textures(material, shading_data, textures_data)
 
 
+def _make_clear_null_updater(null_prop: str):
+    def _update(self: "BIMStylesProperties", context: bpy.types.Context) -> None:
+        self[null_prop] = False
+        update_shader_graph(self, context)
+
+    return _update
+
+
+update_diffuse_colour = _make_clear_null_updater("is_diffuse_colour_null")
+update_specular_colour = _make_clear_null_updater("is_specular_colour_null")
+update_specular_highlight_value = _make_clear_null_updater("is_specular_highlight_null")
+
+
 UV_MODES = [
     ("UV", "UV", _("Actual UV data presented on the geometry")),
     ("Generated", "Generated", _("Automatically-generated UV from the vertex positions of the mesh")),
@@ -221,24 +234,29 @@ class BIMStylesProperties(PropertyGroup):
     transparency: bpy.props.FloatProperty(
         name="Transparency", default=0.0, min=0.0, max=1.0, update=update_shader_graph
     )
-    # TODO: do something on null?
-    is_diffuse_colour_null: BoolProperty(name="Is Null")
+    is_diffuse_colour_null: BoolProperty(name="Is Null", update=update_shader_graph)
     diffuse_colour_class: EnumProperty(
         items=[(x, x, "") for x in get_args(ColourClass)],
         name="Diffuse Colour Class",
-        update=update_shader_graph,
+        update=update_diffuse_colour,
     )
     diffuse_colour: bpy.props.FloatVectorProperty(
-        name="Diffuse Colour", subtype="COLOR", default=(1, 1, 1), min=0.0, max=1.0, size=3, update=update_shader_graph
+        name="Diffuse Colour",
+        subtype="COLOR",
+        default=(1, 1, 1),
+        min=0.0,
+        max=1.0,
+        size=3,
+        update=update_diffuse_colour,
     )
     diffuse_colour_ratio: bpy.props.FloatProperty(
-        name="Diffuse Ratio", default=0.0, min=0.0, max=1.0, update=update_shader_graph
+        name="Diffuse Ratio", default=0.0, min=0.0, max=1.0, update=update_diffuse_colour
     )
-    is_specular_colour_null: BoolProperty(name="Is Null")
+    is_specular_colour_null: BoolProperty(name="Is Null", update=update_shader_graph)
     specular_colour_class: EnumProperty(
         items=[(x, x, "") for x in get_args(ColourClass)],
         name="Specular Colour Class",
-        update=update_shader_graph,
+        update=update_specular_colour,
         default="IfcNormalisedRatioMeasure",
     )
     specular_colour: bpy.props.FloatVectorProperty(
@@ -248,7 +266,7 @@ class BIMStylesProperties(PropertyGroup):
         min=0.0,
         max=1.0,
         size=3,
-        update=update_shader_graph,
+        update=update_specular_colour,
     )
     specular_colour_ratio: bpy.props.FloatProperty(
         name="Specular Ratio",
@@ -256,16 +274,16 @@ class BIMStylesProperties(PropertyGroup):
         default=0.0,
         min=0.0,
         max=1.0,
-        update=update_shader_graph,
+        update=update_specular_colour,
     )
-    is_specular_highlight_null: BoolProperty(name="Is Null")
+    is_specular_highlight_null: BoolProperty(name="Is Null", update=update_shader_graph)
     specular_highlight: bpy.props.FloatProperty(
         name="Specular Highlight",
         description="Used as Roughness value in PHYSICAL Reflectance Method",
         default=0.0,
         min=0.0,
         max=1.0,
-        update=update_shader_graph,
+        update=update_specular_highlight_value,
     )
     reflectance_method: EnumProperty(
         name="Reflectance Method",

src/bonsai/bonsai/bim/module/system/operator.py

@@ -54,7 +54,7 @@ class AddSystem(bpy.types.Operator, tool.Ifc.Operator):
     bl_label = "Add System"
     bl_options = {"REGISTER", "UNDO"}
 
-    parent_system_id: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    parent_system_id: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         parent_system_id: int

src/bonsai/bonsai/bim/module/web/prop.py

@@ -26,16 +26,16 @@ from bpy.types import PropertyGroup
 
 
 class WebProperties(PropertyGroup):
-    webserver_port: IntProperty(  # pyright: ignore[reportRedeclaration]
+    webserver_port: IntProperty(
         name="Webserver Port",
         min=0,
         max=65535,
     )
-    is_running: BoolProperty(  # pyright: ignore[reportRedeclaration]
+    is_running: BoolProperty(
         name="Webserver Running Status",
         default=False,
     )
-    is_connected: BoolProperty(  # pyright: ignore[reportRedeclaration]
+    is_connected: BoolProperty(
         name="Connection Status",
         default=False,
     )

src/bonsai/bonsai/bim/operator.py

@@ -159,9 +159,9 @@ class SelectURIAttribute(bpy.types.Operator, ImportHelper):
     bl_label = "Select URI Attribute"
     bl_options = {"REGISTER", "UNDO"}
     bl_description = "Select a local file"
-    attribute_data_path: bpy.props.StringProperty(name="Data Path")  # pyright: ignore[reportRedeclaration]
+    attribute_data_path: bpy.props.StringProperty(name="Data Path")
     """Full data path to `Attribute`/string property."""
-    use_relative_path: bpy.props.BoolProperty(  # pyright: ignore[reportRedeclaration]
+    use_relative_path: bpy.props.BoolProperty(
         name="Use Relative Path",
         default=False,
     )
@@ -601,7 +601,7 @@ class CreateMacBonsaiApp(bpy.types.Operator):
         "ALT+click to uninstall Bonsai app if it was installed previously."
     )
 
-    uninstall: bpy.props.BoolProperty(options={"SKIP_SAVE"})  # pyright: ignore[reportRedeclaration]
+    uninstall: bpy.props.BoolProperty(options={"SKIP_SAVE"})
 
     if TYPE_CHECKING:
         uninstall: bool
@@ -1667,7 +1667,7 @@ class BIM_OT_attribute_add_subitem(bpy.types.Operator):
     bl_description = "Add subitem to the current attribute"
     bl_options = {"REGISTER", "UNDO"}
 
-    data_path: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    data_path: bpy.props.StringProperty()
     """Full data path."""
 
     if TYPE_CHECKING:
@@ -1691,9 +1691,9 @@ class BIM_OT_attribute_remove_subitem(bpy.types.Operator):
     bl_description = "Add subitem to the current attribute"
     bl_options = {"REGISTER", "UNDO"}
 
-    data_path: bpy.props.StringProperty()  # pyright: ignore[reportRedeclaration]
+    data_path: bpy.props.StringProperty()
     """Full data path."""
-    index: bpy.props.IntProperty()  # pyright: ignore[reportRedeclaration]
+    index: bpy.props.IntProperty()
 
     if TYPE_CHECKING:
         data_path: str

src/bonsai/bonsai/bim/parametric_lifecycle.py

@@ -0,0 +1,462 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2026
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was generated with the assistance of an AI coding tool.
+
+"""Shared operator mixins for parametric-edit operators.
+
+Edit-lifecycle mixins (Enable / Finish / Cancel):
+    `FeatureModifierEditMixin` — door, window (BBIM_<Type> pset; nested
+        lining/panel properties; Finish + Cancel route through
+        ``ifcopenshell.api.feature``).
+    `PathPreservingEditMixin` — railing, roof (path_data preserved across
+        edit; only general kwargs are user-editable).
+
+Pattern selection (which approach a new feature should adopt):
+    Every parametric edit lifecycle commits to one of three patterns. Pick by
+    answering "does the feature share the Enable→Finish→Cancel shape that
+    one of the existing mixins already encodes?":
+
+    A. Inherit one of the shared mixins below and route through
+       `tool.Parametric.build_edit_lifecycle`:
+
+       - `FeatureModifierEditMixin` when the feature stores its pset as
+         `{general fields} + {lining_properties: {...}} + {panel_properties: {...}}`
+         and Finish must call a per-type `update_<type>_modifier_representation`.
+
+       - `PathPreservingEditMixin` when the feature's pset carries a
+         `path_data` field that survives general-kwarg edits untouched, with
+         a separate Enable/Finish/Cancel lifecycle for path editing itself.
+
+    B. Write a per-feature mixin that subclasses `ParametricEditMixinBase`
+       and provides `_enable_targets` / `_finish_targets` / `_cancel_targets`,
+       then route through `build_edit_lifecycle`. Pick this when the
+       feature's pset roundtrip or representation handling diverges from the
+       shared mixins but the Enable→Finish→Cancel shape still fits.
+
+    C. Declare standalone Enable/Finish/Cancel Operator subclasses (no
+       factory) when the feature's parameter-change logic is sufficiently
+       unique that even a per-feature mixin would force optional hooks or
+       dead branches. Such operators MUST call the matrix_world drift
+       helpers (`tool.Geometry.commit_placement_if_moved` on Enable/Finish,
+       `tool.Geometry.restore_or_rebaseline_placement` on Cancel) — the
+       drift contract is enforced uniformly regardless of which pattern the
+       operators adopt.
+
+    The authoritative list of registered parametric types — and which use
+    `build_edit_lifecycle` vs. standalone operators — lives in
+    `tool/parametric.py`'s `EDIT_TYPES` and is enforced by the registry
+    contract tests in `test/bim/test_parametric_registry.py`.
+
+This module hosts operator-side mixins that import ``bonsai.tool`` freely.
+The lightweight parametric registry consumed at addon-enable time must stay
+free of such imports and lives separately in ``tool/parametric.py``."""
+
+from __future__ import annotations
+
+import json
+from collections.abc import Callable
+from typing import TYPE_CHECKING, ClassVar
+
+import bpy
+import ifcopenshell.util.element
+from bpy.app.handlers import persistent
+
+import bonsai.core.geometry
+import bonsai.tool as tool
+
+if TYPE_CHECKING:
+    from ifcopenshell import entity_instance
+
+
+class ParametricEditMixinBase:
+    """Common scaffolding for parametric edit-lifecycle mixins.
+
+    Each per-type subclass provides four hooks:
+
+        ``pset_name``: BBIM_<Type> pset identifier
+        ``_is_element_type(element)``: IFC element predicate
+        ``_get_props(obj)``: PropertyGroup accessor
+        ``_iter_targets(context)``: list of objects to act on (default: ``[active_object]``)
+
+    Drift handling is built in: pre-edit matrix_world drift commits to IFC on
+    Enable, in-edit drag commits on Finish, and Cancel restores the committed
+    IFC placement. This prevents an uncommitted drag from disappearing on
+    Finish or snapping back on Cancel.
+
+    Operator subclasses call one of ``_enable_targets`` / ``_finish_targets`` /
+    ``_cancel_targets`` from their ``_execute`` method."""
+
+    pset_name: ClassVar[str]
+
+    @classmethod
+    def _iter_targets(cls, context: bpy.types.Context) -> list[bpy.types.Object]:
+        obj = context.active_object
+        return [obj] if obj else []
+
+    @classmethod
+    def _is_element_type(cls, element: entity_instance) -> bool:
+        raise NotImplementedError
+
+    @classmethod
+    def _get_props(cls, obj: bpy.types.Object):
+        raise NotImplementedError
+
+    @classmethod
+    def _resolve(cls, obj: bpy.types.Object):
+        """Look up ``(element, props)`` for ``obj`` if it matches this type, else None.
+
+        Common predicate guard for every lifecycle method — collapses the
+        ``element = tool.Ifc.get_entity(obj); assert element; if not is_<type>(element): return``
+        triplet into one call."""
+        element = tool.Ifc.get_entity(obj)
+        if not element or not cls._is_element_type(element):
+            return None
+        return element, cls._get_props(obj)
+
+    @classmethod
+    def _handle_drift_on_enable(cls, obj: bpy.types.Object) -> None:
+        tool.Geometry.commit_placement_if_moved(obj, apply_scale=False)
+
+    @classmethod
+    def _handle_drift_on_finish(cls, obj: bpy.types.Object) -> None:
+        tool.Geometry.commit_placement_if_moved(obj)
+
+    @classmethod
+    def _handle_drift_on_cancel(cls, obj: bpy.types.Object, element: entity_instance) -> None:
+        tool.Geometry.restore_or_rebaseline_placement(obj, element)
+
+    @classmethod
+    def _mark_type_thumbnail_dirty(cls, element: entity_instance) -> None:
+        """Mark the element's type's preview thumbnail for refresh so the
+        property-panel preview reflects post-edit geometry. No-op for
+        occurrences without a backing type."""
+        element_type = ifcopenshell.util.element.get_type(element)
+        if element_type:
+            tool.Model.mark_thumbnail_for_update(element_type)
+
+
+class FeatureModifierEditMixin(ParametricEditMixinBase):
+    """Lifecycle for door- and window-style parametric modifier operators.
+
+    Enable:
+        Read BBIM_<Type> pset JSON → unwrap ``lining_properties`` and
+        ``panel_properties`` → merge constituents data → set draft props →
+        ``is_editing = True``.
+
+    Finish:
+        Gather ``general / lining / panel`` kwargs (project units) → nest →
+        ``is_editing = False`` → call ``_update_modifier_representation`` →
+        mark thumbnail → write back to BBIM_<Type> pset via
+        ``ifcopenshell.api.pset.edit_pset``.
+
+    Cancel:
+        Read BBIM_<Type> pset JSON → unwrap → restore draft props →
+        ``switch_representation`` to the Body representation →
+        ``is_editing = False``."""
+
+    @classmethod
+    def _update_modifier_representation(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
+        """Hook: call the per-type ``update_<type>_modifier_representation``."""
+        raise NotImplementedError
+
+    @classmethod
+    def _enable_one(cls, obj: bpy.types.Object) -> None:
+        resolved = cls._resolve(obj)
+        if resolved is None:
+            return
+        element, props = resolved
+        cls._handle_drift_on_enable(obj)
+        data = json.loads(ifcopenshell.util.element.get_pset(element, cls.pset_name, "Data"))
+        data.update(data.pop("lining_properties"))
+        data.update(data.pop("panel_properties"))
+        data.update(tool.Model.get_constituents_props_data(element))
+        # required since the pset can be loaded from .ifc and the PropertyGroup
+        # would otherwise still hold its default values
+        props.set_props_kwargs_from_ifc_data(data)
+        props.is_editing = True
+
+    @classmethod
+    def _finish_one(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
+        resolved = cls._resolve(obj)
+        if resolved is None:
+            return
+        element, props = resolved
+        data = props.get_general_kwargs(convert_to_project_units=True)
+        data["lining_properties"] = props.get_lining_kwargs(convert_to_project_units=True)
+        data["panel_properties"] = props.get_panel_kwargs(convert_to_project_units=True)
+        cls._update_modifier_representation(obj, context)
+        cls._mark_type_thumbnail_dirty(element)
+        tool.Pset.write_bbim_data(element, cls.pset_name, data)
+        cls._handle_drift_on_finish(obj)
+        # Set only on success: if any IFC op above raised, the user's draft survives for retry.
+        props.is_editing = False
+
+    @classmethod
+    def _cancel_one(cls, obj: bpy.types.Object) -> None:
+        resolved = cls._resolve(obj)
+        if resolved is None:
+            return
+        element, props = resolved
+        # Cancel must always clear is_editing — leaving it True after a
+        # restore-failure would block the user from re-entering edit mode and
+        # the next save's stale-flag heal would silently roll back the
+        # cancellation. Wrap the restore in try/finally so the flag flips
+        # even on partial failure.
+        try:
+            data = json.loads(ifcopenshell.util.element.get_pset(element, cls.pset_name, "Data"))
+            data.update(data.pop("lining_properties"))
+            data.update(data.pop("panel_properties"))
+            props.set_props_kwargs_from_ifc_data(data)
+            body = tool.Geometry.get_body_representation(element)
+            bonsai.core.geometry.switch_representation(tool.Ifc, tool.Geometry, obj=obj, representation=body)
+            cls._handle_drift_on_cancel(obj, element)
+        finally:
+            props.is_editing = False
+
+    def _enable_targets(self, context: bpy.types.Context) -> set[str]:
+        for obj in self._iter_targets(context):
+            self._enable_one(obj)
+        return {"FINISHED"}
+
+    def _finish_targets(self, context: bpy.types.Context) -> set[str]:
+        for obj in self._iter_targets(context):
+            self._finish_one(obj, context)
+        return {"FINISHED"}
+
+    def _cancel_targets(self, context: bpy.types.Context) -> set[str]:
+        for obj in self._iter_targets(context):
+            self._cancel_one(obj)
+        return {"FINISHED"}
+
+
+class PathPreservingEditMixin(ParametricEditMixinBase):
+    """Lifecycle for railing- and roof-style parametric modifier operators.
+
+    Distinctive: ``path_data`` is part of the BBIM_<Type> pset but is **not**
+    user-editable through this lifecycle — it survives the edit untouched, only
+    general kwargs are diffed. (Path editing has its own separate operator
+    pair, ``Enable/Finish/CancelEditing<Type>Path``, out of scope here.)
+
+    Enable:
+        Fetch pset data via ``tool.Model.get_modeling_bbim_pset_data`` → set
+        draft props → ``is_editing = True``. The subclass post-load hook
+        can reshape the dict to fit the PropertyGroup's storage layout
+        (e.g., pre-serialise a structured pset value to JSON for a
+        ``StringProperty`` field).
+
+    Finish:
+        Read fresh pset → keep ``path_data`` → gather ``general`` kwargs
+        (project units) → reassemble → ``is_editing = False`` → call
+        ``_update_pset`` (per-type pset writer) → call ``_update_modifier_ifc_data``
+        (per-type geometry commit).
+
+    Cancel:
+        Read fresh pset → restore draft props → call
+        ``_restore_viewport_after_cancel`` (per-type viewport restore — typically
+        rebuilds the bmesh preview, but subclasses may load a different
+        representation entirely) → ``is_editing = False``."""
+
+    @classmethod
+    def _post_load_data(cls, data: dict) -> dict:
+        """Hook: optionally transform the pset data dict after loading and before
+        passing to ``set_props_kwargs_from_ifc_data``. Default: pass-through.
+
+        Override when the PropertyGroup stores a structured pset field as a
+        serialised primitive — e.g., a list/dict value mapped onto a
+        ``StringProperty`` requires JSON-encoding here."""
+        return data
+
+    @classmethod
+    def _update_pset(cls, element: entity_instance, data: dict) -> None:
+        """Hook: per-type pset writer (``update_bbim_<type>_pset``)."""
+        raise NotImplementedError
+
+    @classmethod
+    def _update_modifier_ifc_data(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
+        """Hook: per-type ``update_<type>_modifier_ifc_data`` — commits the
+        modified geometry to IFC. Signature accepts ``(obj, context)`` so
+        subclasses can forward either argument to their existing helper."""
+        raise NotImplementedError
+
+    @classmethod
+    def _restore_viewport_after_cancel(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
+        """Hook: restore the viewport mesh to match the just-restored draft props.
+
+        Most subclasses rebuild a bmesh preview from props. Subclasses whose
+        committed IFC representation diverges from the preview may switch
+        the mesh back to the committed representation instead."""
+        raise NotImplementedError
+
+    @classmethod
+    def _enable_one(cls, obj: bpy.types.Object) -> None:
+        resolved = cls._resolve(obj)
+        if resolved is None:
+            return
+        _element, props = resolved
+        cls._handle_drift_on_enable(obj)
+        data = tool.Model.get_modeling_bbim_pset_data(obj, cls.pset_name)["data_dict"]
+        data = cls._post_load_data(data)
+        props.set_props_kwargs_from_ifc_data(data)
+        props.is_editing = True
+
+    @classmethod
+    def _finish_one(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
+        resolved = cls._resolve(obj)
+        if resolved is None:
+            return
+        element, props = resolved
+        pset_data = tool.Model.get_modeling_bbim_pset_data(obj, cls.pset_name)
+        stored = pset_data["data_dict"]
+        data = props.get_general_kwargs(convert_to_project_units=True)
+        data["path_data"] = stored["path_data"]
+        # Skip the pset commit when the draft is identical to the stored pset:
+        # an Enable → Finish-without-changes cycle should not pollute the
+        # representation list or burn an undo entry. Drift commit still runs
+        # unconditionally — matrix_world drift is independent of pset content.
+        if data != stored:
+            cls._update_pset(element, data)
+            cls._update_modifier_ifc_data(obj, context)
+            cls._mark_type_thumbnail_dirty(element)
+        cls._handle_drift_on_finish(obj)
+        # Set only on success: if any IFC op above raised, the user's draft survives for retry.
+        props.is_editing = False
+
+    @classmethod
+    def _cancel_one(cls, obj: bpy.types.Object, context: bpy.types.Context) -> None:
+        resolved = cls._resolve(obj)
+        if resolved is None:
+            return
+        element, props = resolved
+        try:
+            pset_data = tool.Model.get_modeling_bbim_pset_data(obj, cls.pset_name)
+            stored = pset_data["data_dict"]
+            draft = props.get_general_kwargs(convert_to_project_units=True)
+            draft["path_data"] = stored["path_data"]
+            nothing_changed = draft == stored
+            data = cls._post_load_data(stored)
+            props.set_props_kwargs_from_ifc_data(data)
+            # Skip the viewport rebuild on a no-op cancel: the mesh on screen is
+            # still the committed representation, and the per-type viewport-restore
+            # hook may be expensive (some subclasses reload a high-poly IFC
+            # representation rather than rebuild a preview mesh).
+            if not nothing_changed:
+                cls._restore_viewport_after_cancel(obj, context)
+            cls._handle_drift_on_cancel(obj, element)
+        finally:
+            # Always clear the flag — see ``FeatureModifierEditMixin._cancel_one``
+            # for the rationale.
+            props.is_editing = False
+
+    def _enable_targets(self, context: bpy.types.Context) -> set[str]:
+        for obj in self._iter_targets(context):
+            self._enable_one(obj)
+        return {"FINISHED"}
+
+    def _finish_targets(self, context: bpy.types.Context) -> set[str]:
+        for obj in self._iter_targets(context):
+            self._finish_one(obj, context)
+        return {"FINISHED"}
+
+    def _cancel_targets(self, context: bpy.types.Context) -> set[str]:
+        for obj in self._iter_targets(context):
+            self._cancel_one(obj, context)
+        return {"FINISHED"}
+
+
+# --- Undo-resync registry ----------------------------------------------------
+#
+# Per-type regenerators called from ``resync_parametric_drafts_after_undo``
+# (wired into ``bim/handler.py:undo_post`` and ``redo_post``) so the preview
+# mesh of an in-progress parametric draft repaints after Ctrl+Z / Ctrl+Shift+Z.
+#
+# Each regenerator is a one-line lazy-import + call. Lazy imports because
+# ``bonsai.bim.parametric_lifecycle`` loads before ``bim/module/model/*``
+# at addon enable; a module-level import would cycle. Each function-local
+# import lands at first call, after the feature module has registered.
+#
+# Types with no entry — door, window, railing, etc. — are IFC-derived: undo
+# of an IFC mutation already restores the entity, and ``switch_representation``
+# repaints the mesh as a side effect of the next refresh. They don't need a
+# bespoke preview regenerator.
+
+
+def _wall_undo_regenerator(obj: bpy.types.Object) -> None:
+    from bonsai.bim.module.model.wall import regenerate_wall_mesh_from_props
+
+    regenerate_wall_mesh_from_props(obj)
+
+
+def _stair_undo_regenerator(obj: bpy.types.Object) -> None:
+    from bonsai.bim.module.model.stair import regenerate_stair_mesh
+
+    regenerate_stair_mesh(obj)
+
+
+def _roof_undo_regenerator(obj: bpy.types.Object) -> None:
+    from bonsai.bim.module.model.roof import update_roof_modifier_bmesh
+
+    update_roof_modifier_bmesh(obj)
+
+
+UNDO_REGENERATORS: dict[str, Callable[[bpy.types.Object], None]] = {
+    "wall": _wall_undo_regenerator,
+    "stair": _stair_undo_regenerator,
+    "roof": _roof_undo_regenerator,
+}
+
+
+def resync_parametric_drafts_after_undo() -> None:
+    """Re-render preview meshes for every parametric draft currently active.
+
+    Walks all objects, skips any not in a registered parametric edit,
+    dispatches to the per-type regenerator in ``UNDO_REGENERATORS``. A type
+    without an entry is left alone — its preview is either already correct
+    (IFC-derived) or has no draft preview mesh."""
+    for obj in bpy.data.objects:
+        feature = tool.Parametric.is_object_editing(obj)
+        if feature is None:
+            continue
+        regenerator = UNDO_REGENERATORS.get(feature.name)
+        if regenerator is None:
+            continue
+        regenerator(obj)
+    tool.Blender.update_all_viewports()
+
+
+@persistent
+def _resync_on_undo(scene: bpy.types.Scene) -> None:
+    resync_parametric_drafts_after_undo()
+
+
+def install_parametric_lifecycle_handlers() -> None:
+    """Append the undo-resync callback to undo_post and redo_post; idempotent.
+
+    Caller must invoke this AFTER appending the central undo/redo handlers so
+    regenerators see restored IFC state — bpy.app.handlers fire in append order."""
+    for hook in (bpy.app.handlers.undo_post, bpy.app.handlers.redo_post):
+        if _resync_on_undo not in hook:
+            hook.append(_resync_on_undo)
+
+
+def uninstall_parametric_lifecycle_handlers() -> None:
+    for hook in (bpy.app.handlers.undo_post, bpy.app.handlers.redo_post):
+        try:
+            hook.remove(_resync_on_undo)
+        except ValueError:
+            pass

src/bonsai/bonsai/bim/prop.py

@@ -333,7 +333,7 @@ class Attribute(PropertyGroup):
     filter_glob: StringProperty()
     is_null: BoolProperty(name="Is Null", update=update_is_null)
     is_selected: BoolProperty(name="Is Selected", default=False)
-    subitems_values: CollectionProperty(type=StrProperty)  # pyright: ignore[reportRedeclaration]
+    subitems_values: CollectionProperty(type=StrProperty)
 
     # Attribute parameters.
     is_optional: BoolProperty(name="Is Optional")
@@ -342,7 +342,7 @@ class Attribute(PropertyGroup):
     value_max: FloatProperty(description="This is used to validate int_value and float_value")
     value_max_constraint: BoolProperty(default=False, description="True if the numerical value has an upper bound")
     special_type: StringProperty(name="Special Value Type", default="")
-    use_explorer_ui: BoolProperty()  # pyright: ignore[reportRedeclaration]
+    use_explorer_ui: BoolProperty()
     metadata: StringProperty(name="Metadata", description="For storing some additional information about the attribute")
     update: StringProperty(name="Update", description="Custom update function to be executed")
 

src/bonsai/bonsai/bim/ui.py

@@ -15,6 +15,8 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 import os
 import platform
@@ -380,6 +382,76 @@ class GizmoPreferencesStair(bpy.types.PropertyGroup):
         cycle: bool
 
 
+class GizmoPreferencesWall(bpy.types.PropertyGroup):
+    """Property group for wall gizmo visibility settings."""
+
+    length: BoolProperty(
+        name="Length",
+        default=True,
+        description="Show the length dimension gizmo along the wall axis.",
+    )
+    height: BoolProperty(
+        name="Height",
+        default=True,
+        description="Show the height dimension gizmo at the wall's start endpoint.",
+    )
+    height_end: BoolProperty(
+        name="Height (far end, walls > 5m)",
+        default=True,
+        description=(
+            "Show a second height gizmo at the wall's far end so long walls don't "
+            "require panning to reach the handle."
+        ),
+    )
+    x_angle: BoolProperty(
+        name="Slope",
+        default=True,
+        description="Show the slope gizmo at the wall top measuring horizontal displacement of the top face.",
+    )
+    cycle: BoolProperty(
+        name="Cycle Offset Baseline",
+        default=True,
+        description="Show the baseline-state icon (Exterior / Centreline / Interior) in the editing icon row.",
+    )
+    scissors: BoolProperty(
+        name="Split at cursor",
+        default=True,
+        description="Show the split icon at the 3D cursor when it lies within the wall's length range.",
+    )
+    extend: BoolProperty(
+        name="Extend length to cursor X",
+        default=True,
+        description="Show the extend-length icon at the 3D cursor's projected wall-axis X.",
+    )
+    extend_height: BoolProperty(
+        name="Extend height to cursor Z",
+        default=True,
+        description="Show the extend-height icon at the 3D cursor's Z, on the wall axis.",
+    )
+    rotate: BoolProperty(
+        name="Rotate 90°",
+        default=True,
+        description="Show the rotate-90 icon in the editing icon row (rotates the wall around its Z axis).",
+    )
+    toggle_openings: BoolProperty(
+        name="Toggle Openings",
+        default=True,
+        description="Show the toggle-openings icon next to the pen (toggles opening fill visibility in the viewport).",
+    )
+
+    if TYPE_CHECKING:
+        length: bool
+        height: bool
+        height_end: bool
+        x_angle: bool
+        cycle: bool
+        scissors: bool
+        extend: bool
+        extend_height: bool
+        rotate: bool
+        toggle_openings: bool
+
+
 class GizmoPreferences(bpy.types.PropertyGroup):
     """Property group for all gizmo visibility settings."""
 
@@ -391,12 +463,14 @@ class GizmoPreferences(bpy.types.PropertyGroup):
     door: bpy.props.PointerProperty(type=GizmoPreferencesDoor)
     window: bpy.props.PointerProperty(type=GizmoPreferencesWindow)
     stair: bpy.props.PointerProperty(type=GizmoPreferencesStair)
+    wall: bpy.props.PointerProperty(type=GizmoPreferencesWall)
 
     if TYPE_CHECKING:
         draw_gizmos_in_3d_viewport: bool
         door: GizmoPreferencesDoor
         window: GizmoPreferencesWindow
         stair: GizmoPreferencesStair
+        wall: GizmoPreferencesWall
 
 
 class DocPreferences(bpy.types.PropertyGroup):
@@ -665,7 +739,7 @@ class BIM_ADDON_preferences(bpy.types.AddonPreferences):
         name="Disable Undo When Saving (Faster saves, no undo for you!)", default=False
     )
     should_stream: BoolProperty(name="Stream Data From IFC-SPF (Only for advanced users)", default=False)
-    should_always_cache: BoolProperty(  # pyright: ignore[reportRedeclaration]
+    should_always_cache: BoolProperty(
         name="Always Cache Geometry",
         description="Whether to always cache geometry regardless of 'Cache' setting during Advanced Project Load.",
     )
@@ -849,49 +923,56 @@ class BIM_ADDON_preferences(bpy.types.AddonPreferences):
         bonsai.bim.helper.draw_expandable_panel(box, context, "Parametric Door", self.draw_door_gizmo_parameters)
         bonsai.bim.helper.draw_expandable_panel(box, context, "Parametric Window", self.draw_window_gizmo_parameters)
         bonsai.bim.helper.draw_expandable_panel(box, context, "Parametric Stair", self.draw_stair_gizmo_parameters)
+        bonsai.bim.helper.draw_expandable_panel(box, context, "Parametric Wall", self.draw_wall_gizmo_parameters)
+
+    def _draw_parametric_gizmo_parameters(
+        self,
+        layout: bpy.types.UILayout,
+        gizmo_pg: bpy.types.PropertyGroup,
+        dimension_gizmo_class: type,
+        special_gizmo_names: frozenset[str] = frozenset(),
+    ) -> None:
+        """Draw the per-element gizmo visibility toggles. Surfaces every annotation
+        on ``gizmo_pg`` that either maps to one of ``dimension_gizmo_class``'s
+        dimension gizmos or is named in ``special_gizmo_names`` (non-dimension icons
+        like baseline cycle, scissors, rotate, …)."""
+        visible_names = {p.attr_name for p in dimension_gizmo_class.dimension_gizmo_props} | special_gizmo_names
+        try:
+            annotations = gizmo_pg.__annotations__
+        except AttributeError:
+            annotations = type(gizmo_pg).__annotations__
+        for prop in annotations:
+            if prop in visible_names:
+                layout.prop(gizmo_pg, prop)
 
     def draw_door_gizmo_parameters(self, layout: bpy.types.UILayout, context: bpy.types.Context) -> None:
         from bonsai.bim.module.model.door import GizmoDoorEdition
 
-        door_gizmos = self.gizmos.door
-        gizmo_prop_names = {p.attr_name for p in GizmoDoorEdition.dimension_gizmo_props}
-        # Add special gizmos not in dimension_gizmo_props
-        gizmo_prop_names.update(("swing_arc", "flip_arc"))
-        try:
-            annotations = door_gizmos.__annotations__
-        except AttributeError:
-            annotations = type(door_gizmos).__annotations__
-        for prop in annotations:
-            if prop in gizmo_prop_names:
-                layout.prop(door_gizmos, prop)
+        self._draw_parametric_gizmo_parameters(
+            layout, self.gizmos.door, GizmoDoorEdition, frozenset({"swing_arc", "flip_arc"})
+        )
 
     def draw_window_gizmo_parameters(self, layout: bpy.types.UILayout, context: bpy.types.Context) -> None:
         from bonsai.bim.module.model.window import GizmoWindowEdition
 
-        window_gizmos = self.gizmos.window
-        gizmo_prop_names = {p.attr_name for p in GizmoWindowEdition.dimension_gizmo_props}
-        try:
-            annotations = window_gizmos.__annotations__
-        except AttributeError:
-            annotations = type(window_gizmos).__annotations__
-        for prop in annotations:
-            if prop in gizmo_prop_names:
-                layout.prop(window_gizmos, prop)
+        self._draw_parametric_gizmo_parameters(layout, self.gizmos.window, GizmoWindowEdition)
 
     def draw_stair_gizmo_parameters(self, layout: bpy.types.UILayout, context: bpy.types.Context) -> None:
         from bonsai.bim.module.model.stair import GizmoStairEdition
 
-        stair_gizmos = self.gizmos.stair
-        gizmo_prop_names = {p.attr_name for p in GizmoStairEdition.dimension_gizmo_props}
-        # Add special gizmos not in dimension_gizmo_props
-        special_gizmo_names = {"lock", "plus", "minus", "cycle"}
-        try:
-            annotations = stair_gizmos.__annotations__
-        except AttributeError:
-            annotations = type(stair_gizmos).__annotations__
-        for prop in annotations:
-            if prop in gizmo_prop_names or prop in special_gizmo_names:
-                layout.prop(stair_gizmos, prop)
+        self._draw_parametric_gizmo_parameters(
+            layout, self.gizmos.stair, GizmoStairEdition, frozenset({"lock", "plus", "minus", "cycle"})
+        )
+
+    def draw_wall_gizmo_parameters(self, layout: bpy.types.UILayout, context: bpy.types.Context) -> None:
+        from bonsai.bim.module.model.wall import GizmoWallEdition
+
+        self._draw_parametric_gizmo_parameters(
+            layout,
+            self.gizmos.wall,
+            GizmoWallEdition,
+            frozenset({"cycle", "scissors", "extend", "extend_height", "rotate", "toggle_openings"}),
+        )
 
     def draw_model_settings(self, layout: bpy.types.UILayout, context: bpy.types.Context) -> None:
         layout.prop(self, "occurrence_name_style")

src/bonsai/bonsai/core/ifcgit.py

@@ -151,8 +151,11 @@ def merge_branch(ifcgit: type[tool.IfcGit], ifc: type[tool.Ifc], operator: bpy.t
         conflicts = ifcgit.git_mergetool(mergetool, path_ifc)
         if conflicts is not None:
             ifcgit.git_merge_abort()
-            ifcgit.store_merge_conflicts(conflicts)
-            operator.report({"WARNING"}, "Merge failed — see the conflict report in the panel below")
+            if conflicts:
+                ifcgit.store_merge_conflicts(conflicts)
+                operator.report({"WARNING"}, "Merge failed — see the conflict report in the panel below")
+            else:
+                operator.report({"ERROR"}, "Merge tool failed — check that ifcmerge is installed correctly")
             return False
         ifcgit.commit_merge(path_ifc)
 

src/bonsai/bonsai/core/model.py

@@ -15,10 +15,13 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Literal, Optional
+import math
+from typing import TYPE_CHECKING, Any, Literal, Optional
 
 if TYPE_CHECKING:
     import bpy
@@ -31,6 +34,24 @@ if TYPE_CHECKING:
     OffsetType = Literal["CENTER", "EXTERIOR", "INTERIOR"]
 
 
+# Arc sample count for fillet preview polylines. 24 samples produces a visually
+# smooth arc at common viewport scales without bloating the GPU batch.
+FILLET_DEFAULT_ARC_RESOLUTION = 24
+# Dot-product floor for treating two wall-axis segments as parallel — below
+# this the projected intersection is too sensitive to floating-point noise
+# to be useful as a junction apex. Calibrated to ~2° from parallel.
+PARALLEL_DOT_THRESHOLD = 0.9994
+# Perpendicular distance (SI metres) under which two parallel wall axes are
+# considered to share the same infinite line. Calibrated to absorb sub-50mm
+# placement drift between authored-joined walls without merging genuinely
+# offset parallel walls.
+COLLINEAR_LINE_TOLERANCE = 0.05
+# Default proximity (SI metres) for classifying a layer offset against the
+# canonical EXTERIOR / CENTER / INTERIOR baselines. Tight enough that ordinary
+# millimetre-scale modelling intent always falls into the nearest baseline.
+BASELINE_OFFSET_TOLERANCE = 0.001
+
+
 def unjoin_walls(
     ifc: type[tool.Ifc],
     blender: type[tool.Blender],
@@ -173,3 +194,438 @@ class RequireAtLeastTwoElements(Exception):
 
 class RequireLayeredElement(Exception):
     pass
+
+
+# --- Wall geometry math (pure) ------------------------------------------------
+# Tuple in / tuple out so these helpers run without ``bpy`` or ``mathutils``.
+# Callers convert ``mathutils.Vector`` at the boundary.
+
+
+def baseline_from_offset(offset: float, thickness: float, tolerance: float = BASELINE_OFFSET_TOLERANCE) -> str:
+    """Classify a numeric layer offset as EXTERIOR / CENTER / INTERIOR.
+
+    Handles both POSITIVE and NEGATIVE direction_sense walls. Returns the
+    closest canonical baseline; falls back to ``"CENTER"`` when nothing is
+    within ``tolerance``."""
+    candidates = (
+        ("EXTERIOR", 0.0),
+        ("CENTER", -thickness / 2),
+        ("INTERIOR", -thickness),
+        ("EXTERIOR", thickness),
+        ("CENTER", thickness / 2),
+        ("INTERIOR", 0.0),
+    )
+    best = min(candidates, key=lambda c: abs(offset - c[1]))
+    return best[0] if abs(offset - best[1]) < tolerance else "CENTER"
+
+
+def project_axis_intersection(
+    seg_a: tuple[tuple[float, float, float], tuple[float, float, float]],
+    seg_b: tuple[tuple[float, float, float], tuple[float, float, float]],
+    parallel_threshold: float,
+) -> Optional[tuple[float, float, float]]:
+    """Compute the 2D (X,Y plane) intersection of two world-space axis segments.
+
+    Each segment is a pair of 3-tuples. Returns the intersection as a 3-tuple
+    (Z is the average of the four input Zs, for visual placement) or ``None`` if
+    the segments are parallel within ``parallel_threshold`` (a dot-product magnitude
+    threshold — see ``PARALLEL_DOT_THRESHOLD`` for the calibrated value)."""
+    p1, p2 = seg_a
+    p3, p4 = seg_b
+    d1x, d1y = p2[0] - p1[0], p2[1] - p1[1]
+    d2x, d2y = p4[0] - p3[0], p4[1] - p3[1]
+    d1_len = (d1x * d1x + d1y * d1y) ** 0.5
+    d2_len = (d2x * d2x + d2y * d2y) ** 0.5
+    if d1_len < 1e-9 or d2_len < 1e-9:
+        return None
+    dot = (d1x * d2x + d1y * d2y) / (d1_len * d2_len)
+    if abs(dot) >= parallel_threshold:
+        return None
+    denom = d1x * d2y - d1y * d2x
+    if abs(denom) < 1e-9:
+        return None
+    t = ((p3[0] - p1[0]) * d2y - (p3[1] - p1[1]) * d2x) / denom
+    ix = p1[0] + t * d1x
+    iy = p1[1] + t * d1y
+    iz = (p1[2] + p2[2] + p3[2] + p4[2]) / 4
+    return (ix, iy, iz)
+
+
+def opening_is_past_cut(min_t: float, cut_percentage: float) -> bool:
+    """True when the opening's near edge sits past the cut on the t axis.
+
+    Strict inequality is load-bearing: a boundary touch or NaN keeps the
+    opening on both walls — the safe default when extent resolution fails."""
+    return min_t > cut_percentage
+
+
+def opening_is_before_cut(max_t: float, cut_percentage: float) -> bool:
+    """True when the opening's far edge sits before the cut on the t axis."""
+    return max_t < cut_percentage
+
+
+def opening_straddles_cut(min_t: float, max_t: float, cut_percentage: float) -> bool:
+    """True when the opening's extent crosses the cut on the t axis."""
+    return min_t < cut_percentage < max_t
+
+
+WallJoinState = Literal["joined", "collinear", "intersect", "none"]
+
+
+def classify_wall_join_state(
+    seg_a: tuple[tuple[float, float, float], tuple[float, float, float]],
+    seg_b: tuple[tuple[float, float, float], tuple[float, float, float]],
+    are_joined: bool,
+    parallel_threshold: float,
+    collinear_tolerance: float,
+) -> tuple[WallJoinState, Optional[tuple[float, float, float]]]:
+    """Classify a wall pair's geometric state — ``(state, intersection)``.
+
+    Priority: ``"joined"`` (caller-supplied flag) → ``"collinear"`` →
+    ``"intersect"`` (projected point returned) → ``"none"`` (parallel,
+    non-collinear)."""
+    if are_joined:
+        return "joined", None
+    if are_axes_collinear(seg_a, seg_b, parallel_threshold, collinear_tolerance):
+        return "collinear", None
+    intersection = project_axis_intersection(seg_a, seg_b, parallel_threshold)
+    if intersection is None:
+        return "none", None
+    return "intersect", intersection
+
+
+def wall_join_preview_lines(
+    seg_a: tuple[tuple[float, float, float], tuple[float, float, float]],
+    seg_b: tuple[tuple[float, float, float], tuple[float, float, float]],
+    intersection: tuple[float, float, float],
+) -> list[tuple[tuple[float, float, float], tuple[float, float, float]]]:
+    """Two segments showing each wall axis extending to ``intersection``.
+
+    Each segment runs from the input axis's nearest endpoint to the
+    intersection, held at that wall's own Z. Returned in input order
+    ``[floor_a, floor_b]``."""
+    ix, iy, _ = intersection
+
+    def _nearest(seg: tuple[tuple[float, float, float], tuple[float, float, float]]) -> tuple[float, float, float]:
+        return min(seg, key=lambda p: (p[0] - ix) ** 2 + (p[1] - iy) ** 2)
+
+    near_a = _nearest(seg_a)
+    near_b = _nearest(seg_b)
+    return [
+        (near_a, (ix, iy, near_a[2])),
+        (near_b, (ix, iy, near_b[2])),
+    ]
+
+
+def resolve_extend_walls_target(
+    target_obj: Any,
+    objs: list[Any],
+    reverse: bool,
+) -> tuple[Any, list[Any]]:
+    """Pick which object is the extend-target and which are extended.
+
+    Default direction: ``objs`` are extended to meet ``target_obj``.
+    Reversed direction (``reverse=True``) swaps the pair — equivalent to
+    having passed them in the opposite order. The swap is well-defined only
+    for the 1+1 case (one target + one other); for ``n>1`` it would be
+    ambiguous, so the default direction is preserved instead."""
+    if reverse and target_obj is not None and len(objs) == 1:
+        return objs[0], [target_obj]
+    return target_obj, objs
+
+
+def displacement_from_x_angle(height: float, x_angle: float) -> float:
+    """Top-edge horizontal displacement for a wall of given vertical ``height``
+    and slope ``x_angle`` (radians). Inverse of ``x_angle_from_displacement``."""
+    return height * math.tan(x_angle)
+
+
+def x_angle_from_displacement(height: float, displacement: float) -> float:
+    """Recover slope ``x_angle`` (radians) from a top-edge horizontal displacement.
+
+    ``height`` is clamped to ``max(height, 1e-6)`` so zero-height walls map
+    cleanly to ``±π/2`` instead of dividing by zero."""
+    return math.atan2(displacement, max(height, 1e-6))
+
+
+def vertical_height_from_extrusion_depth(extrusion_depth: float, x_angle: float) -> float:
+    """Vertical height of a wall given its slanted extrusion depth and slope.
+
+    ``IfcExtrudedAreaSolid.Depth`` measures along the (possibly slanted) extrusion
+    direction. The vertical height the user thinks of is ``depth * cos(x_angle)``.
+    Unit-agnostic: the result is in the same units as ``extrusion_depth``."""
+    return extrusion_depth * abs(math.cos(x_angle))
+
+
+def extrusion_depth_from_vertical_height(vertical_height: float, x_angle: float) -> float:
+    """``vertical_height / cos(x_angle)`` with ``cos`` clamped at ``1e-6`` to
+    stay finite near ``±π/2``."""
+    return vertical_height / max(abs(math.cos(x_angle)), 1e-6)
+
+
+def length_and_height_from_extrusion(
+    extrusion_depth: float,
+    x_angle: float,
+    reference_line_x_extent: float,
+    unit_scale: float,
+) -> tuple[float, float]:
+    """SI ``(length, vertical_height)`` of a LAYER2 wall.
+
+    Height is the *vertical* projection of the slanted depth, not the
+    slanted depth itself."""
+    length = reference_line_x_extent * unit_scale
+    height = vertical_height_from_extrusion_depth(extrusion_depth * unit_scale, x_angle)
+    return length, height
+
+
+def are_axes_collinear(
+    seg_a: tuple[tuple[float, float, float], tuple[float, float, float]],
+    seg_b: tuple[tuple[float, float, float], tuple[float, float, float]],
+    parallel_threshold: float = PARALLEL_DOT_THRESHOLD,
+    line_tolerance: float = COLLINEAR_LINE_TOLERANCE,
+) -> bool:
+    """True if both axis segments lie on the same infinite line in plan.
+
+    Two conditions: directions must be (anti-)parallel within ``parallel_threshold``,
+    AND any endpoint of B must lie on A's infinite line within ``line_tolerance``.
+    Plan-only (Z ignored)."""
+    d1x, d1y = seg_a[1][0] - seg_a[0][0], seg_a[1][1] - seg_a[0][1]
+    d2x, d2y = seg_b[1][0] - seg_b[0][0], seg_b[1][1] - seg_b[0][1]
+    d1_len = (d1x * d1x + d1y * d1y) ** 0.5
+    d2_len = (d2x * d2x + d2y * d2y) ** 0.5
+    if d1_len < 1e-9 or d2_len < 1e-9:
+        return False
+    if abs((d1x * d2x + d1y * d2y) / (d1_len * d2_len)) < parallel_threshold:
+        return False
+    # Project seg_b[0] onto the infinite line through seg_a; the perpendicular
+    # distance to the original point tells us how far off the line B sits.
+    nx, ny = d1x / d1_len, d1y / d1_len
+    dx, dy = seg_b[0][0] - seg_a[0][0], seg_b[0][1] - seg_a[0][1]
+    t = dx * nx + dy * ny
+    proj_x = seg_a[0][0] + nx * t
+    proj_y = seg_a[0][1] + ny * t
+    perp_x = seg_b[0][0] - proj_x
+    perp_y = seg_b[0][1] - proj_y
+    return (perp_x * perp_x + perp_y * perp_y) ** 0.5 < line_tolerance
+
+
+def closest_endpoint_midpoint(
+    seg_a: tuple[tuple[float, float, float], tuple[float, float, float]],
+    seg_b: tuple[tuple[float, float, float], tuple[float, float, float]],
+) -> tuple[float, float, float]:
+    """Midpoint of the closest endpoint pair between two segments."""
+    endpoints_a = (seg_a[0], seg_a[1])
+    endpoints_b = (seg_b[0], seg_b[1])
+
+    def _distance_sq(p: tuple[float, float, float], q: tuple[float, float, float]) -> float:
+        return (p[0] - q[0]) ** 2 + (p[1] - q[1]) ** 2 + (p[2] - q[2]) ** 2
+
+    closest_pair = min(((a, b) for a in endpoints_a for b in endpoints_b), key=lambda pair: _distance_sq(*pair))
+    a, b = closest_pair
+    return ((a[0] + b[0]) / 2, (a[1] + b[1]) / 2, (a[2] + b[2]) / 2)
+
+
+def compute_path_connection_location(
+    seg_self: tuple[tuple[float, float, float], tuple[float, float, float]],
+    self_conn_type: str,
+    seg_other: tuple[tuple[float, float, float], tuple[float, float, float]],
+    other_conn_type: str,
+    parallel_threshold: float = PARALLEL_DOT_THRESHOLD,
+) -> tuple[float, float, float]:
+    """World-space location of a single ``IfcRelConnectsPathElements`` between
+    two wall axes.
+
+    Priority: ``self``'s ATSTART/ATEND endpoint → ``other``'s ATSTART/ATEND
+    endpoint → axis intersection → closest-endpoint midpoint fallback."""
+    if self_conn_type == "ATSTART":
+        return seg_self[0]
+    if self_conn_type == "ATEND":
+        return seg_self[1]
+    if other_conn_type == "ATSTART":
+        return seg_other[0]
+    if other_conn_type == "ATEND":
+        return seg_other[1]
+    intersection = project_axis_intersection(seg_self, seg_other, parallel_threshold)
+    if intersection is not None:
+        return intersection
+    return closest_endpoint_midpoint(seg_self, seg_other)
+
+
+def _vec_sub(a: tuple[float, float, float], b: tuple[float, float, float]) -> tuple[float, float, float]:
+    return (a[0] - b[0], a[1] - b[1], a[2] - b[2])
+
+
+def _vec_dot(a: tuple[float, float, float], b: tuple[float, float, float]) -> float:
+    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2]
+
+
+def _vec_cross(a: tuple[float, float, float], b: tuple[float, float, float]) -> tuple[float, float, float]:
+    return (a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0])
+
+
+def _vec_length(v: tuple[float, float, float]) -> float:
+    return (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]) ** 0.5
+
+
+def _rotate_around_axis(
+    v: tuple[float, float, float],
+    axis: tuple[float, float, float],
+    angle: float,
+) -> tuple[float, float, float]:
+    """Rotate ``v`` around unit-length ``axis`` by ``angle`` radians."""
+    cos_a = math.cos(angle)
+    sin_a = math.sin(angle)
+    dot = _vec_dot(axis, v)
+    cross = _vec_cross(axis, v)
+    k = 1.0 - cos_a
+    return (
+        v[0] * cos_a + cross[0] * sin_a + axis[0] * dot * k,
+        v[1] * cos_a + cross[1] * sin_a + axis[1] * dot * k,
+        v[2] * cos_a + cross[2] * sin_a + axis[2] * dot * k,
+    )
+
+
+def compute_fillet_polylines(
+    seg_a: tuple[tuple[float, float, float], tuple[float, float, float]],
+    seg_b: tuple[tuple[float, float, float], tuple[float, float, float]],
+    radius: float,
+    arc_resolution: int = FILLET_DEFAULT_ARC_RESOLUTION,
+    parallel_threshold: float = PARALLEL_DOT_THRESHOLD,
+) -> dict:
+    """Preview polylines for a circular fillet at the junction of two axes.
+
+    Returns a dict with ``valid``, ``reason``, ``intersection``, ``tangent_a``
+    / ``tangent_b``, ``arc`` (``arc_resolution + 1`` samples), ``arc_center``,
+    ``arc_radius``, ``sweep_angle``, ``sweep_axis``, ``tangent_offset``,
+    ``wall_a_join_side`` / ``wall_b_join_side`` (ATSTART/ATEND/None),
+    ``invalid_radius`` (tangent overshoots — arc + tangents still populated
+    for warning rendering), and ``invalid_axes`` (set on parallel)."""
+    blank: dict = {
+        "valid": False,
+        "reason": None,
+        "intersection": None,
+        "tangent_a": None,
+        "tangent_b": None,
+        "arc": [],
+        "arc_center": None,
+        "arc_radius": radius,
+        "sweep_angle": 0.0,
+        "sweep_axis": None,
+        "tangent_offset": 0.0,
+        "wall_a_join_side": None,
+        "wall_b_join_side": None,
+        "invalid_radius": False,
+        "invalid_axes": None,
+    }
+
+    intersection = project_axis_intersection(seg_a, seg_b, parallel_threshold)
+    if intersection is None:
+        return {**blank, "reason": "parallel", "invalid_axes": [seg_a, seg_b]}
+
+    def _classify(seg, ipt):
+        d0 = (seg[0][0] - ipt[0]) ** 2 + (seg[0][1] - ipt[1]) ** 2 + (seg[0][2] - ipt[2]) ** 2
+        d1 = (seg[1][0] - ipt[0]) ** 2 + (seg[1][1] - ipt[1]) ** 2 + (seg[1][2] - ipt[2]) ** 2
+        if d0 <= d1:
+            return seg[0], seg[1], "ATSTART"
+        return seg[1], seg[0], "ATEND"
+
+    near_a, far_a, side_a = _classify(seg_a, intersection)
+    near_b, far_b, side_b = _classify(seg_b, intersection)
+
+    # Direction along each segment AWAY from the corner. ``far - intersection``
+    # handles both the shared-corner and extended-axes cases uniformly.
+    dir_a_raw = _vec_sub(far_a, intersection)
+    dir_b_raw = _vec_sub(far_b, intersection)
+    far_len_a = _vec_length(dir_a_raw)
+    far_len_b = _vec_length(dir_b_raw)
+    if far_len_a < 1e-9 or far_len_b < 1e-9:
+        return {**blank, "reason": "near_collinear", "intersection": intersection}
+    dir_a = (dir_a_raw[0] / far_len_a, dir_a_raw[1] / far_len_a, dir_a_raw[2] / far_len_a)
+    dir_b = (dir_b_raw[0] / far_len_b, dir_b_raw[1] / far_len_b, dir_b_raw[2] / far_len_b)
+
+    cos_angle = max(-1.0, min(1.0, _vec_dot(dir_a, dir_b)))
+    angle = math.acos(cos_angle)
+    sweep_angle = math.pi - angle
+    if sweep_angle < 1e-3 or sweep_angle > math.pi - 1e-3:
+        return {
+            **blank,
+            "reason": "near_collinear",
+            "intersection": intersection,
+            "sweep_angle": sweep_angle,
+            "wall_a_join_side": side_a,
+            "wall_b_join_side": side_b,
+        }
+
+    tangent_offset = radius * math.tan(sweep_angle / 2)
+    tangent_a = (
+        intersection[0] + dir_a[0] * tangent_offset,
+        intersection[1] + dir_a[1] * tangent_offset,
+        intersection[2] + dir_a[2] * tangent_offset,
+    )
+    tangent_b = (
+        intersection[0] + dir_b[0] * tangent_offset,
+        intersection[1] + dir_b[1] * tangent_offset,
+        intersection[2] + dir_b[2] * tangent_offset,
+    )
+
+    plane_normal_raw = _vec_cross(dir_a, dir_b)
+    pn_len = _vec_length(plane_normal_raw)
+    if pn_len < 1e-9:
+        return {**blank, "reason": "near_collinear", "intersection": intersection}
+    plane_normal = (
+        plane_normal_raw[0] / pn_len,
+        plane_normal_raw[1] / pn_len,
+        plane_normal_raw[2] / pn_len,
+    )
+
+    perp_a = _vec_cross(plane_normal, dir_a)
+    if _vec_dot(perp_a, dir_b) < 0:
+        perp_a = (-perp_a[0], -perp_a[1], -perp_a[2])
+
+    arc_center = (
+        tangent_a[0] + perp_a[0] * radius,
+        tangent_a[1] + perp_a[1] * radius,
+        tangent_a[2] + perp_a[2] * radius,
+    )
+
+    v_a = _vec_sub(tangent_a, arc_center)
+    v_b = _vec_sub(tangent_b, arc_center)
+    sweep_axis = plane_normal
+    if _vec_dot(_vec_cross(v_a, v_b), plane_normal) < 0:
+        sweep_axis = (-plane_normal[0], -plane_normal[1], -plane_normal[2])
+
+    arc_points: list[tuple[float, float, float]] = []
+    for i in range(arc_resolution + 1):
+        t = i / arc_resolution
+        rotated = _rotate_around_axis(v_a, sweep_axis, sweep_angle * t)
+        arc_points.append(
+            (
+                arc_center[0] + rotated[0],
+                arc_center[1] + rotated[1],
+                arc_center[2] + rotated[2],
+            )
+        )
+
+    # Overshoot check only for convex fillets (positive ``tangent_offset``);
+    # the inverted-fillet case puts tangents past the intersection.
+    invalid_radius = tangent_offset > 0 and (tangent_offset > far_len_a or tangent_offset > far_len_b)
+
+    return {
+        "valid": not invalid_radius,
+        "reason": "invalid_radius" if invalid_radius else None,
+        "intersection": intersection,
+        "tangent_a": tangent_a,
+        "tangent_b": tangent_b,
+        "arc": arc_points,
+        "arc_center": arc_center,
+        "arc_radius": radius,
+        "sweep_angle": sweep_angle,
+        "sweep_axis": sweep_axis,
+        "tangent_offset": tangent_offset,
+        "wall_a_join_side": side_a,
+        "wall_b_join_side": side_b,
+        "leg_a_available": far_len_a,
+        "leg_b_available": far_len_b,
+        "invalid_radius": invalid_radius,
+        "invalid_axes": None,
+    }

src/bonsai/bonsai/core/product.py

@@ -0,0 +1,64 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2026
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was generated with the assistance of an AI coding tool.
+
+from __future__ import annotations
+
+import math
+from collections.abc import Iterable
+from typing import TYPE_CHECKING
+
+import bonsai.core.geometry
+
+if TYPE_CHECKING:
+    import bpy
+
+    import bonsai.tool as tool
+
+
+Z_ROTATION_ALIGNMENT_TOLERANCE = 1e-9
+
+
+def _z_rotation_diff(target_z: float, source_z: float) -> float:
+    """Signed Z-Euler difference wrapped to [-π, π]."""
+    return (target_z - source_z + math.pi) % (2 * math.pi) - math.pi
+
+
+def copy_z_rotation_to_selected(
+    ifc: type[tool.Ifc],
+    geometry: type[tool.Geometry],
+    surveyor: type[tool.Surveyor],
+    *,
+    active: bpy.types.Object,
+    targets: Iterable[bpy.types.Object],
+    flip: bool = False,
+) -> int:
+    """Apply ``active``'s Z-Euler rotation to each target."""
+    source_z = surveyor.get_z_rotation(active)
+    if flip:
+        source_z += math.pi
+    rotated = 0
+    for obj in targets:
+        if abs(_z_rotation_diff(surveyor.get_z_rotation(obj), source_z)) < Z_ROTATION_ALIGNMENT_TOLERANCE:
+            continue
+        surveyor.set_z_rotation(obj, source_z)
+        rotated += 1
+        if ifc.get_entity(obj) is not None:
+            bonsai.core.geometry.edit_object_placement(ifc, geometry, surveyor, obj=obj)
+    return rotated

src/bonsai/bonsai/core/tool.py

@@ -415,6 +415,17 @@ class Drawing:
     def update_embedded_svg_location(cls, uri, old_location, new_location): pass
 
 
+@interface
+class Duplicate:
+    def get_decomposition_relationships(cls, objs): pass
+    def get_connection_relationships(cls, objs): pass
+    def get_port_connection_relationships(cls, objs): pass
+    def recreate_decompositions(cls, relationships, old_to_new): pass
+    def recreate_connections(cls, relationship, old_to_new): pass
+    def recreate_port_connections(cls, snapshot, old_to_new): pass
+    def consume_warnings(cls): pass
+
+
 @interface
 class Feature:
     def add_feature(cls, featured_obj, featured_objs): pass
@@ -445,8 +456,10 @@ class Geometry:
     def get_representation_name(cls, representation): pass
     def get_styles(cls, obj): pass
     def get_total_representation_items(cls, obj): pass
+    def has_axis_representation(cls, element): pass
     def has_data_users(cls, data): pass
     def has_material_style_override(cls, obj): pass
+    def has_material_styles(cls, element): pass
     def import_representation_parameters(cls, data): pass
     def is_body_representation(cls, representation): pass
     def is_box_representation(cls, representation): pass
@@ -776,6 +789,12 @@ class Profile:
     def get_profile(cls, element): pass
 
 
+@interface
+class Parametric:
+    def get_geom_generation(cls) -> int: pass
+    def refresh_post_commit(cls) -> None: pass
+
+
 @interface
 class Pset:
     def add_proposed_property(cls, name, value, props): pass
@@ -859,7 +878,6 @@ class Root:
     def assign_body_styles(cls, element, obj): pass
     def copy_representation(cls, source, dest): pass
     def does_type_have_representations(cls, element): pass
-    def get_decomposition_relationships(cls, objs): pass
     def get_default_container(cls): pass
     def get_element_representation(cls, element, context): pass
     def get_element_type(cls, element): pass
@@ -873,7 +891,6 @@ class Root:
     def is_in_nest_mode(cls, element): pass
     def is_spatial_element(cls, element): pass
     def link_object_data(cls, source_obj, destination_obj): pass
-    def recreate_decompositions(cls, relationships, old_to_new): pass
     def run_geometry_add_representation(cls, obj=None, context=None, ifc_representation_class=None, profile_set_usage=None): pass
     def set_object_name(cls, obj, element): pass
 
@@ -1017,6 +1034,8 @@ class Spatial:
     def get_container(cls, element): pass
     def get_decomposed_elements(cls, container, recursive): pass
     def get_decomposition(cls, element): pass
+    def get_host_element(cls, filling): pass
+    def get_host_wall(cls, filling): pass
     def get_object_matrix(cls, obj): pass
     def get_relative_object_matrix(cls, target_obj, relative_to_obj): pass
     def get_root_element(cls, element): pass
@@ -1137,6 +1156,8 @@ class Style:
 @interface
 class Surveyor:
     def get_absolute_matrix(cls, obj): pass
+    def get_z_rotation(cls, obj): pass
+    def set_z_rotation(cls, obj, z): pass
 
 
 @interface
@@ -1203,6 +1224,42 @@ class Voider:
     def void(cls, opening_obj, building_obj): pass
 
 
+@interface
+class Array:
+    def bake_children_transform(cls, parent_element, item): pass
+    def constrain_children_to_parent(cls, parent_element): pass
+    def get_all_children_objects(cls, parent_element): pass
+    def get_all_objects(cls, parent_element): pass
+    def get_child_layer_index(cls, child_element): pass
+    def get_children_objects(cls, modifier_data): pass
+    def get_modifiers_data(cls, parent_element): pass
+    def get_parent_element(cls, element): pass
+    def get_parent_object(cls, element): pass
+    def remove_constraints(cls, parent_element): pass
+    def set_children_lock_state(cls, parent_element, item, lock_state): pass
+
+
+@interface
+class Slab:
+    def read_geometry(cls, obj): pass
+
+
+@interface
+class Wall:
+    def collinear_boundary_world(cls, seg_a, seg_b): pass
+    def compute_wall_fillet_geometry(cls, wall_a_obj, wall_b_obj, radius, arc_resolution): pass
+    def get_axis_local_extent(cls, wall): pass
+    def get_length_and_height(cls, wall): pass
+    def get_world_reference_line(cls, obj): pass
+    def get_x_angle(cls, wall): pass
+    def has_layer2_usage(cls, wall): pass
+    def is_straight_axis(cls, wall): pass
+    def path_connection_location_world(cls, seg_self, self_conn_type, seg_other, other_conn_type, parallel_threshold): pass
+    def read_geometry(cls, obj): pass
+    def validate_for_parametric_edit(cls, obj): pass
+    def walk_connected_walls(cls, start_element, node_cap): pass
+
+
 @interface
 class Web:
     pass

src/bonsai/bonsai/tool/__init__.py

@@ -20,6 +20,7 @@
 # ruff: noqa: F401
 
 from bonsai.tool.aggregate import Aggregate
+from bonsai.tool.array import Array
 from bonsai.tool.attribute import Attribute
 from bonsai.tool.bcf import Bcf
 from bonsai.tool.blender import Blender
@@ -37,6 +38,7 @@ from bonsai.tool.debug import Debug
 from bonsai.tool.demo import Demo
 from bonsai.tool.document import Document
 from bonsai.tool.drawing import Drawing
+from bonsai.tool.duplicate import Duplicate
 from bonsai.tool.feature import Feature
 from bonsai.tool.geometry import Geometry
 from bonsai.tool.georeference import Georeference
@@ -51,6 +53,7 @@ from bonsai.tool.misc import Misc
 from bonsai.tool.model import Model
 from bonsai.tool.nest import Nest
 from bonsai.tool.owner import Owner
+from bonsai.tool.parametric import Parametric
 from bonsai.tool.patch import Patch
 from bonsai.tool.polyline import Polyline
 from bonsai.tool.profile import Profile
@@ -63,6 +66,7 @@ from bonsai.tool.resource import Resource
 from bonsai.tool.root import Root
 from bonsai.tool.search import Search
 from bonsai.tool.sequence import Sequence
+from bonsai.tool.slab import Slab
 from bonsai.tool.snap import Snap
 from bonsai.tool.spatial import Spatial
 from bonsai.tool.structural import Structural
@@ -72,4 +76,5 @@ from bonsai.tool.system import System
 from bonsai.tool.tester import Tester
 from bonsai.tool.type import Type
 from bonsai.tool.unit import Unit
+from bonsai.tool.wall import Wall
 from bonsai.tool.web import Web

src/bonsai/bonsai/tool/array.py

@@ -0,0 +1,207 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2026
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was generated with the assistance of an AI coding tool.
+
+"""Bonsai parametric array service.
+
+Top-level array-domain helpers. The ``BBIM_Array`` pset on a parent ``IfcElement``
+holds the list of layers; each layer holds the GUIDs of its child replicas. These
+helpers navigate that graph and manage the Blender-side CHILD_OF constraint that
+pins children to the parent's matrix_world."""
+
+from __future__ import annotations
+
+import json
+from collections.abc import Generator
+from typing import TYPE_CHECKING, Any
+
+import bpy
+import ifcopenshell
+import ifcopenshell.util.element
+
+import bonsai.core.tool
+import bonsai.tool as tool
+
+if TYPE_CHECKING:
+    from ifcopenshell import entity_instance
+
+
+class Array(bonsai.core.tool.Array):
+    @classmethod
+    def bake_children_transform(cls, parent_element: entity_instance, item: int) -> None:
+        modifier_data = list(cls.get_modifiers_data(parent_element))[item]
+        children = cls.get_children_objects(modifier_data)
+        for child in children:
+            constraint = next((c for c in child.constraints if c.type == "CHILD_OF"), None)
+            if constraint:
+                with bpy.context.temp_override(object=child):
+                    bpy.ops.constraint.apply(constraint=constraint.name, owner="OBJECT")
+
+    @classmethod
+    def constrain_children_to_parent(cls, parent_element: ifcopenshell.entity_instance) -> None:
+        if not (parent_obj := tool.Ifc.get_object(parent_element)):
+            return  # Filtered out, arrayed void, etc
+        assert isinstance(parent_obj, bpy.types.Object)
+        children = cls.get_all_children_objects(parent_element)
+        for child in children:
+            constraint = next((c for c in child.constraints if c.type == "CHILD_OF"), None)
+            if constraint:
+                child.constraints.remove(constraint)
+            constraint = child.constraints.new("CHILD_OF")
+            constraint.name = "BBIM_Array_CHILD_OF"
+            assert isinstance(constraint, bpy.types.ChildOfConstraint)
+            constraint.target = parent_obj
+
+    @classmethod
+    def set_children_lock_state(
+        cls, parent_element: ifcopenshell.entity_instance, item: int, lock_state: bool = True
+    ) -> None:
+        modifier_data = list(cls.get_modifiers_data(parent_element))[item]
+        children = cls.get_children_objects(modifier_data)
+        for child_obj in children:
+            tool.Blender.lock_transform(child_obj, lock_state)
+
+    @classmethod
+    def remove_constraints(cls, parent_element: ifcopenshell.entity_instance) -> None:
+        children = cls.get_all_children_objects(parent_element)
+        for child in children:
+            constraint = next((c for c in child.constraints if c.type == "CHILD_OF"), None)
+            if constraint:
+                child.constraints.remove(constraint)
+
+    @classmethod
+    def get_all_objects(cls, parent_element: ifcopenshell.entity_instance) -> list[bpy.types.Object]:
+        parent_obj = tool.Ifc.get_object(parent_element)
+        assert isinstance(parent_obj, bpy.types.Object)
+        children_objects = list(cls.get_all_children_objects(parent_element))
+        array_objects = [parent_obj] + children_objects  # We ensure the parent is at index 0
+        return array_objects
+
+    @classmethod
+    def get_all_children_objects(
+        cls, parent_element: ifcopenshell.entity_instance
+    ) -> Generator[bpy.types.Object, None, None]:
+        for array_modifier in cls.get_modifiers_data(parent_element):
+            yield from cls.get_children_objects(array_modifier)
+
+    @classmethod
+    def get_parent_element(cls, element: entity_instance) -> entity_instance | None:
+        """Inverse of ``get_all_children_objects``: resolve an array element
+        back to its parent entity. Returns ``None`` when the element isn't
+        part of a Bonsai parametric array, or the stored Parent GUID does
+        not resolve in the current file (this is a data-integrity warning
+        and is logged to the console)."""
+        pset = ifcopenshell.util.element.get_pset(element, "BBIM_Array")
+        if not pset:
+            return None
+        parent_guid = pset["Parent"]
+        try:
+            return tool.Ifc.get().by_guid(parent_guid)
+        except RuntimeError:
+            print(
+                f"BBIM_Array.Parent GUID {parent_guid!r} on {element} does not resolve "
+                f"in the current file — array integrity may be broken."
+            )
+            return None
+
+    @classmethod
+    def get_parent_object(cls, element: entity_instance) -> bpy.types.Object | None:
+        parent_element = cls.get_parent_element(element)
+        if parent_element is None:
+            return None
+        return tool.Ifc.get_object(parent_element)
+
+    @classmethod
+    def get_modifiers_data(cls, parent_element: ifcopenshell.entity_instance) -> Generator[dict[str, Any], None, None]:
+        array_pset = ifcopenshell.util.element.get_pset(parent_element, "BBIM_Array")
+        yield from json.loads(array_pset["Data"])
+
+    @classmethod
+    def get_children_objects(cls, modifier_data: dict[str, Any]) -> Generator[bpy.types.Object, None, None]:
+        child_guid: str
+        for child_guid in modifier_data["children"]:
+            child_obj = tool.Blender.get_object_from_guid(child_guid)
+            if child_obj:
+                yield child_obj
+
+    @classmethod
+    def get_array_root_guid(cls, element: entity_instance) -> str:
+        """Walk ``BBIM_Array.Parent`` upwards and return the topmost ancestor's
+        GlobalId. For an element with no ``BBIM_Array`` pset (independent
+        window, never arrayed, or former-child after the apply path), returns
+        the element's own GlobalId — its "family" is just itself."""
+        current = element
+        seen: set[str] = set()
+        while True:
+            pset = ifcopenshell.util.element.get_pset(current, "BBIM_Array")
+            parent_guid = pset.get("Parent") if pset else None
+            if not parent_guid or parent_guid == current.GlobalId or parent_guid in seen:
+                return current.GlobalId
+            seen.add(parent_guid)
+            try:
+                current = tool.Ifc.get().by_guid(parent_guid)
+            except RuntimeError:
+                return current.GlobalId
+
+    @classmethod
+    def get_parametric_propagation_targets(cls, element: entity_instance) -> list[entity_instance]:
+        """Type-occurrences that should receive parametric updates when
+        ``element`` is edited.
+
+        Returns occurrences in ``element``'s Bonsai array family. When
+        ``element`` is not part of any array, returns the type-occurrence
+        peers that are likewise free of ``BBIM_Array`` (preserving the
+        bulk-edit-by-type UX for standalone parametric elements). An
+        occurrence whose ``BBIM_Array`` root differs from ``element``'s root
+        is excluded — that is the "independent former child" case the array
+        apply path produces."""
+        occurrences = tool.Ifc.get_all_element_occurrences(element)
+        element_pset = ifcopenshell.util.element.get_pset(element, "BBIM_Array")
+        if not element_pset:
+            return [o for o in occurrences if not ifcopenshell.util.element.get_pset(o, "BBIM_Array")]
+        element_root = cls.get_array_root_guid(element)
+        return [o for o in occurrences if cls.get_array_root_guid(o) == element_root]
+
+    @classmethod
+    def get_child_layer_index(cls, child_element: entity_instance) -> int | None:
+        """Index of the layer that produced ``child_element``, or ``None``
+        if the child is unparented, missing from the parent's data, or the
+        parent's pset is unreadable. Total: never raises."""
+        pset = ifcopenshell.util.element.get_pset(child_element, "BBIM_Array")
+        if not pset:
+            return None
+        parent_guid = pset.get("Parent")
+        if not parent_guid or parent_guid == child_element.GlobalId:
+            return None
+        try:
+            parent_element = tool.Ifc.get().by_guid(parent_guid)
+        except RuntimeError:
+            return None
+        data_text = ifcopenshell.util.element.get_pset(parent_element, "BBIM_Array", "Data")
+        if not data_text:
+            return None
+        try:
+            layers = json.loads(data_text)
+        except (ValueError, TypeError):
+            return None
+        child_guid = child_element.GlobalId
+        for i, layer in enumerate(layers):
+            if child_guid in layer.get("children", []):
+                return i
+        return None

src/bonsai/bonsai/tool/blender.py

@@ -15,12 +15,13 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 from __future__ import annotations
 
 import contextlib
 import importlib
-import json
 import os
 import platform
 import subprocess
@@ -28,7 +29,7 @@ import sys
 import tempfile
 import traceback
 import types
-from collections.abc import Callable, Generator, Iterable, Sequence, Sized
+from collections.abc import Callable, Generator, Iterable, Mapping, Sequence, Sized
 from datetime import datetime
 from functools import cache, lru_cache
 from pathlib import Path
@@ -45,7 +46,6 @@ from typing import (
 
 import bmesh
 import bpy
-import ifcopenshell.api
 import ifcopenshell.util.element
 import numpy as np
 import numpy.typing as npt
@@ -55,12 +55,12 @@ from mathutils import Matrix, Vector
 import bonsai.bim
 import bonsai.core.tool
 import bonsai.tool as tool
-from bonsai.bim.ifc import IFC_CONNECTED_TYPE
 
 if TYPE_CHECKING:
     import bpy.stub_internal.rna_enums as rna_enums
     from sun_position.properties import SunPosProperties
 
+    from bonsai.bim.ifc import IFC_CONNECTED_TYPE
     from bonsai.bim.module.attribute.prop import BIMAttributeProperties
     from bonsai.bim.module.constraint.prop import (
         BIMConstraintProperties,
@@ -97,6 +97,19 @@ VIEWPORT_ATTRIBUTES = [
 
 OBJECT_DATA_TYPE = Union[bpy.types.Mesh, bpy.types.Curve, bpy.types.Camera]
 
+_RAILING_MODIFIER_IFC_CLASSES = ("IfcRailing", "IfcRailingType")
+_STAIR_MODIFIER_IFC_CLASSES = (
+    "IfcStairFlight",
+    "IfcStairFlightType",
+    "IfcMember",
+    "IfcMemberType",
+    "IfcStair",
+    "IfcStairType",
+)
+_WINDOW_MODIFIER_IFC_CLASSES = ("IfcWindow", "IfcWindowType", "IfcWindowStyle")
+_DOOR_MODIFIER_IFC_CLASSES = ("IfcDoor", "IfcDoorType", "IfcDoorStyle")
+_ROOF_MODIFIER_IFC_CLASSES = ("IfcRoof", "IfcRoofType")
+
 
 class Blender(bonsai.core.tool.Blender):
     OBJECT_TYPES_THAT_SUPPORT_EDIT_MODE = ("MESH", "CURVE", "SURFACE", "META", "FONT", "LATTICE", "ARMATURE")
@@ -415,6 +428,189 @@ class Blender(bonsai.core.tool.Blender):
         with bpy.context.temp_override(**cls.get_viewport_context()):
             bpy.ops.wm.tool_set_by_id(name=tool_name)
 
+    @classmethod
+    def are_viewport_gizmos_enabled(cls) -> bool:
+        """Central gate every Bonsai gizmo poll / decorator draw checks before
+        rendering. Centralises the read of
+        ``gizmos.draw_gizmos_in_3d_viewport`` from addon preferences."""
+        return cls.get_addon_preferences().gizmos.draw_gizmos_in_3d_viewport
+
+    class DecoratorColors(NamedTuple):
+        selected: tuple
+        unselected: tuple
+        special: tuple
+        error: tuple
+        background: tuple
+
+    @classmethod
+    def get_decorator_colors(cls) -> Blender.DecoratorColors:
+        """The five ``decorator_color_*`` fields read together so each viewport
+        decorator's draw callback resolves them in one call instead of five."""
+        prefs = cls.get_addon_preferences()
+        return cls.DecoratorColors(
+            selected=prefs.decorator_color_selected,
+            unselected=prefs.decorator_color_unselected,
+            special=prefs.decorator_color_special,
+            error=prefs.decorator_color_error,
+            background=prefs.decorator_color_background,
+        )
+
+    class ViewportDecorator:
+        """Shared ``SpaceView3D.draw_handler_add`` lifecycle for feature decorators.
+
+        Single-handler subclasses set ``draw_method`` (default ``"draw"``); the
+        handler binds at ``POST_VIEW``. Multi-handler subclasses set
+        ``draw_methods`` to a tuple of ``(method_name, phase)`` pairs; when it
+        is non-``None`` it supersedes ``draw_method``.
+
+        Decorators whose ``install`` must accept extra arguments (e.g. a callback
+        or a precomputed bmesh) override ``install`` themselves."""
+
+        draw_method: str = "draw"
+        draw_methods: tuple[tuple[str, str], ...] | None = None
+
+        def __init_subclass__(cls, **kwargs):
+            super().__init_subclass__(**kwargs)
+            cls.handlers = []
+            cls.is_installed = False
+            # Fail loudly at class-definition time if draw_method / draw_methods
+            # names an attribute the class doesn't expose. Without this, a typo
+            # only surfaces on the first redraw — as a silent missing-attribute
+            # handler — which may be far from the offending declaration.
+            method_names = (
+                tuple(name for name, _phase in cls.draw_methods) if cls.draw_methods is not None else (cls.draw_method,)
+            )
+            for name in method_names:
+                if getattr(cls, name, None) is None:
+                    raise TypeError(f"{cls.__name__}: draw method {name!r} is declared but not defined on the class")
+
+        @classmethod
+        def install(cls, context: bpy.types.Context) -> None:
+            if cls.is_installed:
+                cls.uninstall()
+            handler = cls()
+            bindings = cls.draw_methods if cls.draw_methods is not None else ((cls.draw_method, "POST_VIEW"),)
+            # Rollback partial registrations on any draw_handler_add failure, so
+            # cls.handlers never ends up holding a half-installed set.
+            added: list = []
+            try:
+                for method_name, phase in bindings:
+                    added.append(
+                        bpy.types.SpaceView3D.draw_handler_add(
+                            getattr(handler, method_name), (context,), "WINDOW", phase
+                        )
+                    )
+            except Exception:
+                for h in added:
+                    try:
+                        bpy.types.SpaceView3D.draw_handler_remove(h, "WINDOW")
+                    except ValueError:
+                        pass
+                raise
+            cls.handlers = added
+            cls.is_installed = True
+
+        @classmethod
+        def uninstall(cls) -> None:
+            for h in cls.handlers:
+                try:
+                    bpy.types.SpaceView3D.draw_handler_remove(h, "WINDOW")
+                except ValueError:
+                    pass
+            cls.handlers.clear()
+            cls.is_installed = False
+
+        @staticmethod
+        def _lookup_active_instance(gizmo_cls: type, context: bpy.types.Context) -> Optional[Any]:
+            """Return the live ``GizmoGroup`` instance registered under
+            ``context.region``, or ``None`` if there isn't one. The per-region
+            weakref dict on the gizmo class is populated by ``setup()``; multi-
+            viewport setups put one entry per region in it so each region's
+            decorator sees only its own region's hover state."""
+            instances = getattr(gizmo_cls, "_active_instances", None)
+            if not instances:
+                return None
+            region = getattr(context, "region", None)
+            if region is None:
+                return None
+            ref = instances.get(region.as_pointer())
+            if ref is None:
+                return None
+            return ref()
+
+        def _cursor_icon_hovered(self, gizmo_cls: type, attr_name: str, context: bpy.types.Context) -> bool:
+            """True iff the gizmo group instance in the current region exposes a gizmo
+            under ``attr_name`` that reports as highlighted. Any access exception is
+            swallowed so a transient bpy-state hiccup never breaks the draw loop."""
+            inst = self._lookup_active_instance(gizmo_cls, context)
+            if inst is None:
+                return False
+            try:
+                return bool(getattr(inst, attr_name).is_highlight)
+            except (AttributeError, ReferenceError):
+                return False
+
+        @classmethod
+        def sync_all(
+            cls,
+            context: bpy.types.Context,
+            enabled: Mapping[type[Blender.ViewportDecorator], bool],
+        ) -> None:
+            """Drive each listed decorator to its desired install state in one call.
+
+            Each entry whose value is ``True`` ends up installed; each entry whose
+            value is ``False`` ends up uninstalled. Pass ``True`` for always-on
+            overlays so they survive subsequent file loads."""
+            for decorator_cls, should_install in enabled.items():
+                if should_install:
+                    decorator_cls.install(context)
+                else:
+                    decorator_cls.uninstall()
+
+    @classmethod
+    def is_view_top_down(cls, context: bpy.types.Context, threshold: float = 0.9659) -> bool:
+        """True when the viewport camera is looking ~straight down (or up) the world Z axis.
+
+        Default threshold of 0.9659 = cos(15°) — a 15° tilt cone around ±world Z.
+        Above the threshold the world-Z axis projects to a small fraction of its
+        true length on screen, so callers that lay icons or markers out along
+        world Z should switch to a screen-space offset and any gizmo whose intent
+        is specifically "vertical" loses its visual cue. The cone is kept narrow
+        so vertical-intent gizmos stay visible across the typical orbit range of
+        3D viewport work and drop out only near genuine plan view."""
+        rv3d = context.region_data
+        if rv3d is None:
+            return False
+        view_forward = Vector(rv3d.view_matrix.inverted().col[2][:3]).normalized()
+        return abs(view_forward.z) > threshold
+
+    @classmethod
+    def top_down_factor(cls, context: bpy.types.Context, threshold: float = 0.9659) -> float:
+        """Continuous 0–1 ramp matching ``is_view_top_down``'s cone: 0 outside the
+        cone, ramping linearly to 1 at strict alignment with world Z. Callers that
+        want a proportional effect (an icon-stack lift growing as the view
+        approaches plan) use this in place of the boolean to avoid a one-frame
+        visual jump as the camera crosses the threshold."""
+        rv3d = context.region_data
+        if rv3d is None:
+            return 0.0
+        view_forward = Vector(rv3d.view_matrix.inverted().col[2][:3]).normalized()
+        alignment = abs(view_forward.z)
+        if alignment <= threshold:
+            return 0.0
+        return (alignment - threshold) / (1.0 - threshold)
+
+    @classmethod
+    def get_screen_up_world(cls, context: bpy.types.Context) -> Vector:
+        """World-space direction corresponding to the camera's up axis (screen-vertical).
+
+        Returns ``+Y`` when region data is unavailable so callers can compute an
+        offset without a guard branch."""
+        rv3d = context.region_data
+        if rv3d is None:
+            return Vector((0.0, 1.0, 0.0))
+        return Vector(rv3d.view_matrix.inverted().col[1][:3]).normalized()
+
     @classmethod
     def get_shader_editor_context(cls) -> Union[dict[str, Any], None]:
         for screen in bpy.data.screens:
@@ -484,9 +680,13 @@ class Blender(bonsai.core.tool.Blender):
 
     @classmethod
     def update_all_viewports(cls, context: bpy.types.Context | None = None) -> None:
+        """Tag every visible 3D viewport for redraw. Silent no-op when no
+        screen attached (background mode, plug-out, mid-load_post)."""
         context = context or bpy.context
-        assert context.screen
-        for area in context.screen.areas:
+        screen = getattr(context, "screen", None)
+        if screen is None:
+            return
+        for area in screen.areas:
             if area.type == "VIEW_3D":
                 area.tag_redraw()
 
@@ -635,10 +835,11 @@ class Blender(bonsai.core.tool.Blender):
         op_text = "" if ui_context == "TOOL_HEADER" else text
         modifier_icon, modifier_str = cls.KEY_MODIFIERS.get(modifier, ("NONE", ""))
 
-        row = layout if ui_context == "TOOL_HEADER" else layout.row(align=True)
         module = sys.modules[module_name]
         icon_previews: Union[bpy.utils.previews.ImagePreviewCollection, None]
         icon_previews = getattr(module, "custom_icon_previews", None)
+
+        row = layout if ui_context == "TOOL_HEADER" else layout.row(align=True)
         if icon_previews:
             custom_icon = icon_previews.get(text.upper().replace(" ", "_"), icon_previews["IFC"]).icon_id
             op = row.operator(operator_to_use, text=op_text, icon_value=custom_icon)
@@ -646,6 +847,7 @@ class Blender(bonsai.core.tool.Blender):
             op = row.operator(operator_to_use, text=op_text)
         if ui_context != "TOOL_HEADER":
             row.label(text="", icon=modifier_icon)
+            row.separator(factor=1)
             row.label(text="", icon=f"EVENT_{key}")
 
         if operator_to_use == hotkey_operator:
@@ -1130,6 +1332,74 @@ class Blender(bonsai.core.tool.Blender):
         return True
 
     class Modifier:
+        # ----------------------------------------------------------------------
+        # FIXME(PR5): backward-compat shims for callers still using the
+        # pre-refactor API. The is_<type> predicates now live on tool.Parametric;
+        # the Array helper bag now lives on tool.Array. PR4 migrates each caller;
+        # this whole shim block is removed in PR5's cleanup.
+        # ----------------------------------------------------------------------
+
+        @classmethod
+        def is_door(cls, element: entity_instance) -> bool:
+            return tool.Parametric.is_door(element)
+
+        @classmethod
+        def is_railing(cls, element: entity_instance) -> bool:
+            return tool.Parametric.is_railing(element)
+
+        @classmethod
+        def is_roof(cls, element: entity_instance) -> bool:
+            return tool.Parametric.is_roof(element)
+
+        @classmethod
+        def is_stair(cls, element: entity_instance) -> bool:
+            return tool.Parametric.is_stair(element)
+
+        @classmethod
+        def is_wall(cls, element: entity_instance) -> bool:
+            return tool.Parametric.is_wall(element)
+
+        @classmethod
+        def is_window(cls, element: entity_instance) -> bool:
+            return tool.Parametric.is_window(element)
+
+        class Array:
+            @classmethod
+            def bake_children_transform(cls, parent_element: ifcopenshell.entity_instance, item: int) -> None:
+                tool.Array.bake_children_transform(parent_element, item)
+
+            @classmethod
+            def constrain_children_to_parent(cls, parent_element: ifcopenshell.entity_instance) -> None:
+                tool.Array.constrain_children_to_parent(parent_element)
+
+            @classmethod
+            def get_all_children_objects(cls, parent_element: ifcopenshell.entity_instance) -> list:
+                return tool.Array.get_all_children_objects(parent_element)
+
+            @classmethod
+            def get_all_objects(cls, parent_element: ifcopenshell.entity_instance) -> list:
+                return tool.Array.get_all_objects(parent_element)
+
+            @classmethod
+            def get_children_objects(cls, modifier_data: dict) -> list:
+                return tool.Array.get_children_objects(modifier_data)
+
+            @classmethod
+            def get_modifiers_data(cls, parent_element: ifcopenshell.entity_instance):
+                return tool.Array.get_modifiers_data(parent_element)
+
+            @classmethod
+            def remove_constraints(cls, parent_element: ifcopenshell.entity_instance) -> None:
+                tool.Array.remove_constraints(parent_element)
+
+            @classmethod
+            def set_children_lock_state(
+                cls, parent_element: ifcopenshell.entity_instance, item: int, lock: bool
+            ) -> None:
+                tool.Array.set_children_lock_state(parent_element, item, lock)
+
+        # ----------------------------------------------------------------------
+
         @classmethod
         def try_applying_edit_mode(cls, obj: bpy.types.Object, element: entity_instance) -> bool:
             """Tries to validate the current BIM modifier parameters for the active object
@@ -1137,20 +1407,18 @@ class Blender(bonsai.core.tool.Blender):
 
             :return: True if an action was taken, False otherwise
             """
-            if cls.is_roof(element):
-                if cls.is_editing_roof_parameters(obj):
-                    bpy.ops.bim.finish_editing_roof()
+            # roof and railing both finalize then drop into path-edit mode — handle
+            # them before the generic finish dispatch so the path transition runs.
+            if tool.Parametric.is_roof(element):
+                if tool.Parametric.ROOF.is_editing(obj):
+                    tool.Parametric.run_bim_op(tool.Parametric.ROOF.finish_op)
                 bpy.ops.bim.enable_editing_roof_path()
-            elif cls.is_railing(element):
-                if cls.is_editing_railing_parameters(obj):
-                    bpy.ops.bim.finish_editing_railing()
+            elif tool.Parametric.is_railing(element):
+                if tool.Parametric.RAILING.is_editing(obj):
+                    tool.Parametric.run_bim_op(tool.Parametric.RAILING.finish_op)
                 bpy.ops.bim.enable_editing_railing_path()
-            elif cls.is_editing_stair_parameters(obj):
-                bpy.ops.bim.finish_editing_stair()
-            elif cls.is_editing_door_parameters(obj):
-                bpy.ops.bim.finish_editing_door()
-            elif cls.is_editing_window_parameters(obj):
-                bpy.ops.bim.finish_editing_window()
+            elif feature := tool.Parametric.is_object_editing(obj):
+                tool.Parametric.run_bim_op(feature.finish_op)
             else:
                 return False
             return True
@@ -1161,68 +1429,80 @@ class Blender(bonsai.core.tool.Blender):
 
             :return: True if an action was taken, False otherwise
             """
+            # Path-edit modes are distinct from parametric draft modes; handle them first.
             if cls.is_editing_railing_path(obj):
                 bpy.ops.bim.cancel_editing_railing_path()
             elif cls.is_editing_roof_path(obj):
                 bpy.ops.bim.cancel_editing_roof_path()
-            elif cls.is_editing_railing_parameters(obj):
-                bpy.ops.bim.cancel_editing_railing()
-            elif cls.is_editing_door_parameters(obj):
-                bpy.ops.bim.cancel_editing_door()
-            elif cls.is_editing_window_parameters(obj):
-                bpy.ops.bim.cancel_editing_window()
-            elif cls.is_editing_roof_parameters(obj):
-                bpy.ops.bim.cancel_editing_roof()
-            elif cls.is_editing_stair_parameters(obj):
-                bpy.ops.bim.cancel_editing_stair()
+            elif feature := tool.Parametric.is_object_editing(obj):
+                tool.Parametric.run_bim_op(feature.cancel_op)
             else:
                 return False
             return True
 
         @classmethod
         def is_eligible_for_railing_modifier(cls, obj: bpy.types.Object) -> bool:
-            return tool.Blender.is_object_an_ifc_class(obj, ("IfcRailing", "IfcRailingType"))
+            return tool.Blender.is_object_an_ifc_class(obj, _RAILING_MODIFIER_IFC_CLASSES)
 
         @classmethod
         def is_eligible_for_stair_modifier(cls, obj: bpy.types.Object) -> bool:
-            return tool.Blender.is_object_an_ifc_class(
-                obj, ("IfcStairFlight", "IfcStairFlightType", "IfcMember", "IfcMemberType", "IfcStair", "IfcStairType")
-            )
+            return tool.Blender.is_object_an_ifc_class(obj, _STAIR_MODIFIER_IFC_CLASSES)
 
         @classmethod
         def is_eligible_for_window_modifier(cls, obj: bpy.types.Object) -> bool:
-            return tool.Blender.is_object_an_ifc_class(obj, ("IfcWindow", "IfcWindowType", "IfcWindowStyle"))
+            return tool.Blender.is_object_an_ifc_class(obj, _WINDOW_MODIFIER_IFC_CLASSES)
 
         @classmethod
         def is_eligible_for_door_modifier(cls, obj: bpy.types.Object) -> bool:
-            return tool.Blender.is_object_an_ifc_class(obj, ("IfcDoor", "IfcDoorType", "IfcDoorStyle"))
+            return tool.Blender.is_object_an_ifc_class(obj, _DOOR_MODIFIER_IFC_CLASSES)
 
         @classmethod
         def is_eligible_for_roof_modifier(cls, obj: bpy.types.Object) -> bool:
-            return tool.Blender.is_object_an_ifc_class(obj, ("IfcRoof", "IfcRoofType"))
+            return tool.Blender.is_object_an_ifc_class(obj, _ROOF_MODIFIER_IFC_CLASSES)
 
         @classmethod
-        def is_railing(cls, element: entity_instance) -> bool:
-            return tool.Pset.get_element_pset(element, "BBIM_Railing")
+        def is_array_child(cls, element: entity_instance) -> bool:
+            """True if element is a CHILD of a Bonsai parametric array.
+
+            Children are managed replicas regenerated from the parent's pset —
+            their parametric attributes (door dimensions, wall lengths, …) are
+            overwritten on the next ``regenerate_array``. Parametric gizmo
+            groups skip children via this predicate in ``poll``.
+
+            This sits on a different axis from ``tool.Parametric.is_array``:
+            cardinality (parent vs child) is orthogonal to feature kind, and
+            an arrayed wall fires both ``is_wall`` and ``is_array`` on the
+            same element."""
+            if element is None:
+                return False
+            pset = ifcopenshell.util.element.get_pset(element, "BBIM_Array")
+            if not pset:
+                return False
+            parent_guid = pset.get("Parent")
+            return parent_guid is not None and parent_guid != element.GlobalId
 
         @classmethod
-        def is_roof(cls, element: entity_instance) -> bool:
-            return tool.Pset.get_element_pset(element, "BBIM_Roof")
+        def is_slab(cls, element: entity_instance) -> bool:
+            """A slab is host-eligible for the parametric add-opening gizmo if
+            it is an IfcSlab with LAYER3 usage.
+
+            Slabs carry no proprietary BBIM_Slab pset — their parametric state
+            lives in standard IFC (extrusion depth, IfcMaterialLayerSetUsage
+            with LayerSetDirection AXIS3). Any LAYER3 slab qualifies."""
+            if element is None or not element.is_a("IfcSlab"):
+                return False
+            return tool.Model.get_usage_type(element) == "LAYER3"
 
         @classmethod
-        def is_window(cls, element: entity_instance) -> bool:
-            return tool.Pset.get_element_pset(element, "BBIM_Window")
+        def is_pipe_segment(cls, element: entity_instance) -> bool:
+            return element is not None and element.is_a("IfcPipeSegment")
 
         @classmethod
-        def is_door(cls, element: entity_instance) -> bool:
-            return tool.Pset.get_element_pset(element, "BBIM_Door")
+        def is_duct_segment(cls, element: entity_instance) -> bool:
+            return element is not None and element.is_a("IfcDuctSegment")
 
         @classmethod
-        def is_stair(cls, element: entity_instance) -> bool:
-            return tool.Pset.get_element_pset(element, "BBIM_Stair")
-
-        @classmethod
-        def is_editing_railing_path(cls, obj: bpy.types.Object):
+        def is_editing_railing_path(cls, obj: bpy.types.Object) -> bool:
             props = tool.Model.get_railing_props(obj)
             return props.is_editing_path
 
@@ -1231,107 +1511,10 @@ class Blender(bonsai.core.tool.Blender):
             props = tool.Model.get_roof_props(obj)
             return props.is_editing_path
 
-        @classmethod
-        def is_editing_railing_parameters(cls, obj: bpy.types.Object) -> bool:
-            props = tool.Model.get_railing_props(obj)
-            return props.is_editing
-
-        @classmethod
-        def is_editing_roof_parameters(cls, obj: bpy.types.Object) -> bool:
-            props = tool.Model.get_roof_props(obj)
-            return props.is_editing
-
-        @classmethod
-        def is_editing_window_parameters(cls, obj: bpy.types.Object) -> bool:
-            props = tool.Model.get_window_props(obj)
-            return props.is_editing
-
-        @classmethod
-        def is_editing_door_parameters(cls, obj: bpy.types.Object) -> bool:
-            props = tool.Model.get_door_props(obj)
-            return props.is_editing
-
-        @classmethod
-        def is_editing_stair_parameters(cls, obj: bpy.types.Object) -> bool:
-            props = tool.Model.get_stair_props(obj)
-            return props.is_editing
-
         @classmethod
         def is_modifier_with_non_editable_path(cls, element: entity_instance) -> bool:
-            return cls.is_stair(element) or cls.is_door(element) or cls.is_window(element)
-
-        class Array:
-            @classmethod
-            def bake_children_transform(cls, parent_element: entity_instance, item: int) -> None:
-                modifier_data = list(cls.get_modifiers_data(parent_element))[item]
-                children = cls.get_children_objects(modifier_data)
-                for child in children:
-                    constraint = next((c for c in child.constraints if c.type == "CHILD_OF"), None)
-                    if constraint:
-                        with bpy.context.temp_override(object=child):
-                            bpy.ops.constraint.apply(constraint=constraint.name, owner="OBJECT")
-
-            @classmethod
-            def constrain_children_to_parent(cls, parent_element: ifcopenshell.entity_instance) -> None:
-                if not (parent_obj := tool.Ifc.get_object(parent_element)):
-                    return  # Filtered out, arrayed void, etc
-                assert isinstance(parent_obj, bpy.types.Object)
-                children = cls.get_all_children_objects(parent_element)
-                for child in children:
-                    constraint = next((c for c in child.constraints if c.type == "CHILD_OF"), None)
-                    if constraint:
-                        child.constraints.remove(constraint)
-                    constraint = child.constraints.new("CHILD_OF")
-                    constraint.name = "BBIM_Array_CHILD_OF"
-                    assert isinstance(constraint, bpy.types.ChildOfConstraint)
-                    constraint.target = parent_obj
-
-            @classmethod
-            def set_children_lock_state(
-                cls, parent_element: ifcopenshell.entity_instance, item: int, lock_state: bool = True
-            ) -> None:
-                modifier_data = list(cls.get_modifiers_data(parent_element))[item]
-                children = cls.get_children_objects(modifier_data)
-                for child_obj in children:
-                    Blender.lock_transform(child_obj, lock_state)
-
-            @classmethod
-            def remove_constraints(cls, parent_element: ifcopenshell.entity_instance) -> None:
-                children = cls.get_all_children_objects(parent_element)
-                for child in children:
-                    constraint = next((c for c in child.constraints if c.type == "CHILD_OF"), None)
-                    if constraint:
-                        child.constraints.remove(constraint)
-
-            @classmethod
-            def get_all_objects(cls, parent_element: ifcopenshell.entity_instance) -> list[bpy.types.Object]:
-                parent_obj = tool.Ifc.get_object(parent_element)
-                assert isinstance(parent_obj, bpy.types.Object)
-                children_objects = list(cls.get_all_children_objects(parent_element))
-                array_objects = [parent_obj] + children_objects  # We ensure the parent is at index 0
-                return array_objects
-
-            @classmethod
-            def get_all_children_objects(
-                cls, parent_element: ifcopenshell.entity_instance
-            ) -> Generator[bpy.types.Object, None, None]:
-                for array_modifier in cls.get_modifiers_data(parent_element):
-                    yield from cls.get_children_objects(array_modifier)
-
-            @classmethod
-            def get_modifiers_data(
-                cls, parent_element: ifcopenshell.entity_instance
-            ) -> Generator[dict[str, Any], None, None]:
-                array_pset = ifcopenshell.util.element.get_pset(parent_element, "BBIM_Array")
-                yield from json.loads(array_pset["Data"])
-
-            @classmethod
-            def get_children_objects(cls, modifier_data: dict[str, Any]) -> Generator[bpy.types.Object, None, None]:
-                child_guid: str
-                for child_guid in modifier_data["children"]:
-                    child_obj = tool.Blender.get_object_from_guid(child_guid)
-                    if child_obj:
-                        yield child_obj
+            feature = tool.Parametric.find_for_element(element)
+            return bool(feature and feature.has_non_editable_path)
 
     class Attribute:
         @classmethod

src/bonsai/bonsai/tool/cad.py

@@ -32,6 +32,7 @@ from __future__ import annotations
 
 import math
 import sys
+from collections.abc import Sequence
 from typing import TYPE_CHECKING, Union
 
 import bmesh
@@ -45,6 +46,13 @@ if TYPE_CHECKING:
 
 
 VTX_PRECISION = 1.0e-5
+# Tolerances below are in Blender units (SI metres).
+# Looser than VTX_PRECISION because regen-time numeric drift exceeds CAD snap precision.
+WELD_TOLERANCE = 1.0e-4
+# How close a vertex must be to the cut plane to count as on it.
+BISECT_TOLERANCE = 1.0e-4
+# Strict weld for cleaning up exactly-coincident vertices.
+WELD_EPSILON = 1.0e-6
 
 
 class Cad:
@@ -996,3 +1004,106 @@ class Cad:
             y = height_half + height_half * (prj[1] / w)
             return Vector((float(x), float(y)))
         return default
+
+    @classmethod
+    def sweep_disk_along_polyline(
+        cls,
+        bm: bmesh.types.BMesh,
+        points: Sequence[Vector],
+        radius: float,
+        arc_indices: Sequence[int] = (),
+        profile_segments: int = 8,
+    ) -> None:
+        """Append a tube of ``radius`` along the polyline ``points`` to ``bm``.
+
+        Viewport-quality approximation of an IFC ``IfcSweptDiskSolid``: each
+        consecutive pair of points becomes a capped cylinder. The cylinders
+        overlap at joints rather than being mitered — the visual artifact is
+        negligible at typical handrail radii (~25mm) and acceptable for
+        live parametric-edit preview.
+
+        ``arc_indices`` is accepted for API symmetry with the IFC builder
+        (which receives the same data structure), but is currently unused —
+        arcs are visualised as polyline kinks. Tessellating each arc with a
+        Lagrange or circular interpolation would smooth the joints; deferred
+        until profile fidelity becomes a concern.
+
+        :param bm: target bmesh, mutated in place.
+        :param points: polyline vertices.
+        :param radius: tube radius (project units).
+        :param arc_indices: indices of arc midpoints (currently ignored).
+        :param profile_segments: sides on each cylinder cross-section.
+        """
+        del arc_indices  # accepted for forward compatibility; see docstring
+        if len(points) < 2:
+            return
+        for p0, p1 in zip(points, points[1:]):
+            cls._add_capped_cylinder(bm, Vector(p0), Vector(p1), radius, profile_segments)
+
+    @classmethod
+    def add_disk_extrusion(
+        cls,
+        bm: bmesh.types.BMesh,
+        position: Vector,
+        radius: float,
+        depth: float,
+        axis_rotation_z: float,
+        profile_segments: int = 12,
+    ) -> None:
+        """Append a flat cylinder (disk extrusion) to ``bm``.
+
+        A disk of ``radius`` extruded by ``depth`` along the +Y axis rotated
+        by ``axis_rotation_z`` radians around Z. ``position`` is the disk's
+        base, not its centre.
+
+        :param bm: target bmesh, mutated in place.
+        :param position: base of the extrusion in object-local coordinates.
+        :param radius: disk radius.
+        :param depth: extrusion depth along the (rotated) Y axis.
+        :param axis_rotation_z: rotation around Z applied to the +Y axis to
+            obtain the extrusion direction.
+        :param profile_segments: sides on the disk's edge.
+        """
+        # The +Y axis rotated by axis_rotation_z around Z gives the extrusion
+        # direction: (-sin(θ), cos(θ), 0). The disk axis points along it.
+        axis = Vector((-math.sin(axis_rotation_z), math.cos(axis_rotation_z), 0.0))
+        end = position + axis * depth
+        cls._add_capped_cylinder(bm, position, end, radius, profile_segments)
+
+    @classmethod
+    def _add_capped_cylinder(
+        cls,
+        bm: bmesh.types.BMesh,
+        p0: Vector,
+        p1: Vector,
+        radius: float,
+        segments: int,
+    ) -> None:
+        """Append one capped cylinder of ``radius`` from ``p0`` to ``p1`` to ``bm``."""
+        direction = p1 - p0
+        length = direction.length
+        if length < 1e-9:
+            return
+        direction = direction / length
+
+        z_axis = Vector((0.0, 0.0, 1.0))
+        dot = direction.dot(z_axis)
+        if dot > 1.0 - 1e-6:
+            rotation = Matrix.Identity(4)
+        elif dot < -1.0 + 1e-6:
+            # Anti-parallel: rotate 180° around X so the cone flips bottom-to-top.
+            rotation = Matrix.Rotation(math.pi, 4, "X")
+        else:
+            rotation = z_axis.rotation_difference(direction).to_matrix().to_4x4()
+
+        matrix = Matrix.Translation((p0 + p1) * 0.5) @ rotation
+        bmesh.ops.create_cone(
+            bm,
+            cap_ends=True,
+            cap_tris=False,
+            segments=segments,
+            radius1=radius,
+            radius2=radius,
+            depth=length,
+            matrix=matrix,
+        )

src/bonsai/bonsai/tool/collector.py

@@ -135,6 +135,7 @@ class Collector(bonsai.core.tool.Collector):
 
         if element.is_a("IfcFeatureElementSubtraction"):
             obj.display_type = "WIRE"
+            obj.display.show_shadows = False
 
     @classmethod
     def _create_project_child_collection(cls, name: str) -> bpy.types.Collection:

src/bonsai/bonsai/tool/cost.py

@@ -987,7 +987,8 @@ class Cost(bonsai.core.tool.Cost):
     def disable_editing_cost_item_parent(cls) -> None:
         props = cls.get_cost_props()
         props.active_cost_item_id = 0
-        props.change_cost_item_parent = False
+        if props.change_cost_item_parent == True:
+            props.change_cost_item_parent = False
 
     @classmethod
     def load_cost_item_quantities(cls, cost_item: Optional[ifcopenshell.entity_instance] = None) -> None:

src/bonsai/bonsai/tool/drawing.py

@@ -1756,6 +1756,10 @@ class Drawing(bonsai.core.tool.Drawing):
             # For section/elevation views, elevate the segment vertically
             if not (points := helper.elevate_segment(bounds, [v1, v2])):
                 return
+        elif target_view == "MODEL_VIEW":
+            # For model views, clip to XY bounds and keep Z (3D line at true elevation)
+            if not (points := helper.clip_segment(bounds, [v1, v2])):
+                return
         else:
             return
 

src/bonsai/bonsai/tool/duplicate.py

@@ -0,0 +1,328 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+
+# This file was generated with the assistance of an AI coding tool.
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from typing import Any, Literal
+
+import bpy
+import ifcopenshell
+import ifcopenshell.util.element
+import ifcopenshell.util.placement
+import ifcopenshell.util.representation
+
+import bonsai.core.geometry
+import bonsai.core.tool
+import bonsai.tool as tool
+
+
+@dataclass
+class DecompositionRecord:
+    type: Literal["fill"]
+    element: ifcopenshell.entity_instance
+
+
+@dataclass
+class ConnectionRecord:
+    type: Literal["path"]
+    relating_element: ifcopenshell.entity_instance
+    related_element: ifcopenshell.entity_instance
+    relating_connection_type: str
+    related_connection_type: str
+    relating_priorities: list[int]
+    related_priorities: list[int]
+
+
+@dataclass
+class PortConnectionRecord:
+    relating_port_index: int
+    related_element: ifcopenshell.entity_instance
+    related_port_index: int
+    direction: str
+
+
+@dataclass
+class PortConnectionSnapshot:
+    """Port-to-port connections and per-element port counts captured before duplication."""
+
+    by_element: dict[ifcopenshell.entity_instance, list[PortConnectionRecord]] = field(default_factory=dict)
+    port_counts: dict[ifcopenshell.entity_instance, int] = field(default_factory=dict)
+
+
+class Duplicate(bonsai.core.tool.Duplicate):
+
+    _pending_warnings: list[str] = []
+
+    @classmethod
+    def _emit_warning(cls, message: str) -> None:
+        """Buffer a warning for later retrieval by an operator. Falling through
+        to a print keeps the message in the Blender console for the headless /
+        no-operator code path."""
+        cls._pending_warnings.append(message)
+        print(f"Bonsai: WARNING — {message}")
+
+    @classmethod
+    def consume_warnings(cls) -> list[str]:
+        """Return and clear the buffered warnings — operators call this after
+        ``tool.Geometry.duplicate_ifc_objects`` to forward each to ``self.report``."""
+        warnings = cls._pending_warnings
+        cls._pending_warnings = []
+        return warnings
+
+    @classmethod
+    def get_decomposition_relationships(
+        cls, objs: list[bpy.types.Object]
+    ) -> dict[ifcopenshell.entity_instance, DecompositionRecord]:
+        relationships: dict[ifcopenshell.entity_instance, DecompositionRecord] = {}
+        for obj in objs:
+            element = tool.Ifc.get_entity(obj)
+            if not element:
+                continue
+            if building := tool.Spatial.get_host_element(element):
+                relationships[element] = DecompositionRecord(type="fill", element=building)
+        return relationships
+
+    @classmethod
+    def get_connection_relationships(
+        cls, objs: list[bpy.types.Object]
+    ) -> dict[ifcopenshell.entity_instance, ConnectionRecord]:
+        relationships: dict[ifcopenshell.entity_instance, ConnectionRecord] = {}
+        for obj in objs:
+            element = tool.Ifc.get_entity(obj)
+            if not element:
+                continue
+            if hasattr(element, "ConnectedTo") and element.ConnectedTo:
+                paths = [
+                    connection for connection in element.ConnectedTo if connection.is_a("IfcRelConnectsPathElements")
+                ]
+                for path in paths:
+                    relationships[element] = ConnectionRecord(
+                        type="path",
+                        relating_element=path.RelatingElement,
+                        related_element=path.RelatedElement,
+                        relating_connection_type=path.RelatingConnectionType,
+                        related_connection_type=path.RelatedConnectionType,
+                        relating_priorities=list(path.RelatingPriorities or []),
+                        related_priorities=list(path.RelatedPriorities or []),
+                    )
+        return relationships
+
+    @classmethod
+    def get_port_connection_relationships(cls, objs: list[bpy.types.Object]) -> PortConnectionSnapshot:
+        """Snapshot ``IfcRelConnectsPorts`` among MEP elements in ``objs``, indexed for positional-port replay onto duplicates."""
+        # Function-local: top-level import would trigger a partial-init cycle.
+        from bonsai.tool.system import direction_from_port_pair
+
+        snapshot = PortConnectionSnapshot()
+        elements_in_set: set[ifcopenshell.entity_instance] = set()
+        for obj in objs:
+            element = tool.Ifc.get_entity(obj)
+            if element is not None and tool.System.is_mep_element(element):
+                elements_in_set.add(element)
+        if not elements_in_set:
+            return snapshot
+
+        ordered_elements = sorted(elements_in_set, key=lambda e: e.id())
+        for element in ordered_elements:
+            snapshot.port_counts[element] = len(tool.System.get_ports(element))
+
+        seen: set[tuple[tuple[int, int], tuple[int, int]]] = set()
+        for element in ordered_elements:
+            ports = tool.System.get_ports(element)
+            for port_index, port in enumerate(ports):
+                connected_port = tool.System.get_connected_port(port)
+                if connected_port is None:
+                    continue
+                other_element = tool.System.get_port_relating_element(connected_port)
+                if other_element is None or other_element not in elements_in_set:
+                    continue
+                other_ports = tool.System.get_ports(other_element)
+                try:
+                    other_port_index = other_ports.index(connected_port)
+                except ValueError:
+                    continue
+                pair_key = tuple(
+                    sorted(
+                        [
+                            (element.id(), port_index),
+                            (other_element.id(), other_port_index),
+                        ]
+                    )
+                )
+                if pair_key in seen:
+                    continue
+                seen.add(pair_key)
+
+                snapshot.by_element.setdefault(element, []).append(
+                    PortConnectionRecord(
+                        relating_port_index=port_index,
+                        related_element=other_element,
+                        related_port_index=other_port_index,
+                        direction=direction_from_port_pair(port, connected_port),
+                    )
+                )
+        return snapshot
+
+    @classmethod
+    def recreate_decompositions(
+        cls,
+        relationships: dict[ifcopenshell.entity_instance, DecompositionRecord],
+        old_to_new: dict[ifcopenshell.entity_instance, list[ifcopenshell.entity_instance]],
+    ) -> None:
+        for subelement, data in relationships.items():
+            new_subelements = old_to_new.get(subelement)
+            new_elements = old_to_new.get(data.element)
+            if not new_subelements or not new_elements:
+                continue
+            for i, new_subelement in enumerate(new_subelements):
+                new_element = new_elements[i]
+                if data.type == "fill":
+                    element = new_element
+                    filling = new_subelement
+                    voided_obj = tool.Ifc.get_object(new_element)
+                    filling_obj = tool.Ifc.get_object(new_subelement)
+
+                    existing_opening_occurrence = subelement.FillsVoids[0].RelatingOpeningElement
+                    opening = tool.Ifc.run("root.copy_class", product=existing_opening_occurrence)
+                    tool.Ifc.run(
+                        "geometry.edit_object_placement",
+                        product=opening,
+                        matrix=ifcopenshell.util.placement.get_local_placement(opening.ObjectPlacement),
+                        is_si=False,
+                    )
+
+                    representation = ifcopenshell.util.representation.get_representation(
+                        existing_opening_occurrence, "Model", "Body", "MODEL_VIEW"
+                    )
+                    representation = ifcopenshell.util.representation.resolve_representation(representation)
+                    mapped_representation = tool.Ifc.run("geometry.map_representation", representation=representation)
+                    tool.Ifc.run(
+                        "geometry.assign_representation",
+                        product=opening,
+                        representation=mapped_representation,
+                    )
+                    tool.Ifc.run("feature.add_feature", feature=opening, element=element)
+                    tool.Ifc.run("feature.add_filling", opening=opening, element=filling)
+
+                    voided_objs = [voided_obj]
+                    # Openings affect all subelements of an aggregate
+                    for child_subelement in ifcopenshell.util.element.get_decomposition(element):
+                        subobj = tool.Ifc.get_object(child_subelement)
+                        if subobj:
+                            voided_objs.append(subobj)
+
+                    for voided_obj in voided_objs:
+                        if mesh_data := voided_obj.data:
+                            representation = tool.Ifc.get().by_id(
+                                tool.Geometry.get_mesh_props(mesh_data).ifc_definition_id
+                            )
+                            bonsai.core.geometry.switch_representation(
+                                tool.Ifc,
+                                tool.Geometry,
+                                obj=voided_obj,
+                                representation=representation,
+                            )
+
+    @classmethod
+    def recreate_connections(
+        cls,
+        relationship: dict[ifcopenshell.entity_instance, ConnectionRecord],
+        old_to_new: dict[ifcopenshell.entity_instance, list[ifcopenshell.entity_instance]],
+    ) -> None:
+        for element, data in relationship.items():
+            try:
+                new_relating_element = old_to_new.get(data.relating_element)[0]
+                new_related_element = old_to_new.get(data.related_element)[0]
+            except (KeyError, IndexError, TypeError):
+                continue
+            new_rel = tool.Ifc.run(
+                "geometry.connect_path",
+                relating_element=new_relating_element,
+                related_element=new_related_element,
+                relating_connection=data.relating_connection_type,
+                related_connection=data.related_connection_type,
+            )
+            # connect_path hardcodes priorities to []; restore them post-hoc.
+            priority_attrs: dict[str, Any] = {}
+            if data.relating_priorities:
+                priority_attrs["RelatingPriorities"] = data.relating_priorities
+            if data.related_priorities:
+                priority_attrs["RelatedPriorities"] = data.related_priorities
+            if new_rel is not None and priority_attrs:
+                try:
+                    tool.Ifc.run("attribute.edit_attributes", product=new_rel, attributes=priority_attrs)
+                except (RuntimeError, ifcopenshell.Error) as e:
+                    cls._emit_warning(
+                        f"connection priority restore failed for {new_rel}; "
+                        f"duplicate has empty RelatingPriorities/RelatedPriorities: {e}"
+                    )
+
+    @classmethod
+    def recreate_port_connections(
+        cls,
+        snapshot: PortConnectionSnapshot,
+        old_to_new: dict[ifcopenshell.entity_instance, list[ifcopenshell.entity_instance]],
+    ) -> None:
+        """Recreate ``IfcRelConnectsPorts`` between duplicates; skip records whose duplicate's port count diverges from the snapshot."""
+        for relating_element, records in snapshot.by_element.items():
+            for record in records:
+                related_element = record.related_element
+                try:
+                    new_relating = old_to_new[relating_element][0]
+                    new_related = old_to_new[related_element][0]
+                except (KeyError, IndexError):
+                    continue
+
+                new_relating_ports = tool.System.get_ports(new_relating)
+                new_related_ports = tool.System.get_ports(new_related)
+
+                expected_relating = snapshot.port_counts.get(relating_element)
+                if expected_relating is not None and len(new_relating_ports) != expected_relating:
+                    cls._emit_warning(
+                        f"port reconnect skipped — duplicate has {len(new_relating_ports)} ports, "
+                        f"snapshot had {expected_relating}"
+                    )
+                    continue
+                expected_related = snapshot.port_counts.get(related_element)
+                if expected_related is not None and len(new_related_ports) != expected_related:
+                    cls._emit_warning(
+                        f"port reconnect skipped — duplicate has {len(new_related_ports)} ports, "
+                        f"snapshot had {expected_related}"
+                    )
+                    continue
+
+                try:
+                    new_port_a = new_relating_ports[record.relating_port_index]
+                    new_port_b = new_related_ports[record.related_port_index]
+                except IndexError:
+                    cls._emit_warning(
+                        f"port reconnect skipped — record references port index past the duplicate's port list"
+                    )
+                    continue
+                try:
+                    tool.Ifc.run(
+                        "system.connect_port",
+                        port1=new_port_a,
+                        port2=new_port_b,
+                        direction=record.direction or "NOTDEFINED",
+                    )
+                except (RuntimeError, ifcopenshell.Error) as e:
+                    cls._emit_warning(f"port reconnect failed between duplicates: {e}")

src/bonsai/bonsai/tool/geometry.py

@@ -73,7 +73,7 @@ import bonsai.core.style
 import bonsai.core.system
 import bonsai.core.tool
 import bonsai.tool as tool
-from bonsai.bim.ifc import IfcStore
+from bonsai.bim.ifc import IfcStore, get_cache_or_detect_lock
 
 if TYPE_CHECKING:
     from bonsai.bim.module.geometry.prop import (
@@ -115,10 +115,42 @@ class Geometry(bonsai.core.tool.Geometry):
 
     @classmethod
     def clear_cache(cls, element: ifcopenshell.entity_instance) -> None:
-        cache = IfcStore.get_cache()
+        # Cache acquisition can fail if the HDF5 file is locked by another
+        # process — degrade gracefully rather than aborting the caller's
+        # reimport flow. A stale cache entry is harmless; a raised exception
+        # prevents the actual mesh swap. The wrapper sets the project-panel
+        # warning flag on lock so the user sees one prominent notice instead
+        # of per-element log spam.
+        try:
+            cache = get_cache_or_detect_lock()
+        except Exception as exc:
+            print(f"clear_cache: skipping cache invalidation for {element} ({exc})")
+            return
         if cache and hasattr(element, "GlobalId"):
             cache.remove(element.GlobalId)
 
+    @classmethod
+    def has_axis_representation(cls, element: ifcopenshell.entity_instance) -> bool:
+        """True if the element carries a shape representation whose
+        RepresentationIdentifier is 'Axis'. Elements without one cannot be
+        projected to an unambiguous 1D path; callers that draw schematic axis
+        overlays must skip them rather than fall back to mesh-derived geometry."""
+        product_rep = getattr(element, "Representation", None)
+        if product_rep is None:
+            return False
+        for rep in product_rep.Representations:
+            if getattr(rep, "RepresentationIdentifier", None) == "Axis":
+                return True
+        return False
+
+    @classmethod
+    def get_body_representation(cls, element: ifcopenshell.entity_instance) -> ifcopenshell.entity_instance | None:
+        """The element's ``Model/Body/MODEL_VIEW`` representation, or ``None``.
+        Single source for the ``(context, identifier, target_view)`` triple used
+        by every body-geometry reader across walls, slabs, doors, openings, and
+        feature decorators."""
+        return ifcopenshell.util.representation.get_representation(element, "Model", "Body", "MODEL_VIEW")
+
     @classmethod
     def clear_modifiers(cls, obj: bpy.types.Object) -> None:
         for modifier in obj.modifiers:
@@ -389,6 +421,29 @@ class Geometry(bonsai.core.tool.Geometry):
             bm.free()
             del mesh["ios_edges"]
 
+    @classmethod
+    def get_dissolved_edges(
+        cls,
+        mesh: bpy.types.Mesh,
+        angle_limit: float = radians(1.0),
+    ) -> tuple[list[Vector], list[tuple[int, int]]]:
+        # Read-only on `mesh`: builds a throwaway bmesh, dissolves coplanar
+        # edges while preserving material seams, returns wire-overlay data.
+        bm = bmesh.new()
+        bm.from_mesh(mesh)
+        bmesh.ops.dissolve_limit(
+            bm,
+            angle_limit=angle_limit,
+            verts=bm.verts,
+            edges=bm.edges,
+            delimit={"MATERIAL"},
+        )
+        bm.verts.index_update()
+        verts = [v.co.copy() for v in bm.verts]
+        edges = [(e.verts[0].index, e.verts[1].index) for e in bm.edges]
+        bm.free()
+        return verts, edges
+
     @classmethod
     def apply_item_ids_as_vertex_groups(cls, obj: bpy.types.Object) -> None:
         """Save mesh-object item_ids as vertex groups in format 'ios_item_id_xxxx'.
@@ -788,6 +843,15 @@ class Geometry(bonsai.core.tool.Geometry):
                 return True
         return False
 
+    @classmethod
+    def has_material_styles(cls, element: ifcopenshell.entity_instance) -> bool:
+        """True when any of ``element``'s materials exposes an
+        ``IfcSurfaceStyle``. Gate body-style assignment to avoid double-styling."""
+        return any(
+            tool.Material.get_style(material) is not None
+            for material in ifcopenshell.util.element.get_materials(element)
+        )
+
     @classmethod
     def reimport_element_representations(
         cls, obj: bpy.types.Object, representation: ifcopenshell.entity_instance, apply_openings: bool = True
@@ -1154,6 +1218,53 @@ class Geometry(bonsai.core.tool.Geometry):
         props.location_checksum = repr(tool.Blender.np_array_legacy(obj.matrix_world.translation).tobytes())
         props.rotation_checksum = repr(tool.Blender.np_array_legacy(obj.matrix_world.to_3x3()).tobytes())
 
+    @classmethod
+    def commit_placement_if_moved(cls, obj: bpy.types.Object, *, apply_scale: bool = True) -> None:
+        """Write ``obj.matrix_world`` back to its IFC ``ObjectPlacement`` when the
+        object has drifted since its last placement commit.
+
+        Scope: drop-in only when the gate is exactly ``is_moved(obj)``. Call sites
+        whose gate is wider (e.g. ``is_moved OR is_scaled``) or already enforced
+        upstream (inside an ``if is_moved:`` block) should call
+        ``edit_object_placement`` directly to avoid the redundant inner check."""
+        if not tool.Ifc.is_moved(obj):
+            return
+        bonsai.core.geometry.edit_object_placement(
+            tool.Ifc, tool.Geometry, tool.Surveyor, obj=obj, apply_scale=apply_scale
+        )
+
+    @classmethod
+    def restore_placement_from_ifc(cls, obj: bpy.types.Object, element: ifcopenshell.entity_instance) -> None:
+        """Snap ``obj.matrix_world`` back to ``element``'s committed IFC placement,
+        then re-baseline the drift checksum so ``tool.Ifc.is_moved(obj)`` returns
+        False afterwards.
+
+        Precondition: ``element.ObjectPlacement`` must not be None. Callers in a
+        cancel-style flow that want a "restore-or-clear-drift" semantic must gate
+        on ObjectPlacement themselves and call ``record_object_position`` directly
+        in the no-placement branch."""
+        assert element.ObjectPlacement is not None, (
+            "restore_placement_from_ifc requires ObjectPlacement — gate the caller "
+            "or use restore_or_rebaseline_placement for the restore-or-clear-drift semantic"
+        )
+        matrix_np = ifcopenshell.util.placement.get_local_placement(element.ObjectPlacement).copy()
+        unit_scale = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())
+        matrix_np[:3, 3] *= unit_scale
+        obj.matrix_world = tool.Loader.apply_blender_offset_to_matrix_world(obj, matrix_np)
+        cls.record_object_position(obj)
+
+    @classmethod
+    def restore_or_rebaseline_placement(cls, obj: bpy.types.Object, element: ifcopenshell.entity_instance) -> None:
+        """Cancel-flow placement restore: revert ``obj.matrix_world`` to the committed
+        IFC placement; when the element has no ObjectPlacement, re-baseline the drift
+        checksum instead so a subsequent edit does not silently commit the discarded drag."""
+        if not tool.Ifc.is_moved(obj):
+            return
+        if element.ObjectPlacement is None:
+            cls.record_object_position(obj)
+            return
+        cls.restore_placement_from_ifc(obj, element)
+
     @classmethod
     def remove_connection(cls, connection: ifcopenshell.entity_instance) -> None:
         tool.Ifc.get().remove(connection)
@@ -1205,6 +1316,20 @@ class Geometry(bonsai.core.tool.Geometry):
         bpy.data.objects.remove(obj)
         return new_obj
 
+    @classmethod
+    def detach_representation(cls, product: ifcopenshell.entity_instance) -> None:
+        """Replace ``product.Representation`` with a deep copy so the product
+        no longer shares its representation tree (mapped or direct) with any
+        other entity. The ``IfcGeometricRepresentationContext`` is excluded
+        from the copy so contexts stay file-singletons. No-op when the
+        product has no ``Representation`` attribute or it is unset."""
+        rep = getattr(product, "Representation", None)
+        if rep is None:
+            return
+        product.Representation = ifcopenshell.util.element.copy_deep(
+            tool.Ifc.get(), rep, exclude=["IfcGeometricRepresentationContext"]
+        )
+
     @classmethod
     def resolve_mapped_representation(
         cls, representation: ifcopenshell.entity_instance
@@ -2132,8 +2257,11 @@ class Geometry(bonsai.core.tool.Geometry):
 
         new_active_obj = None
         # Track decompositions so they can be recreated after the operation
-        decomposition_relationships = tool.Root.get_decomposition_relationships(objects_to_duplicate)
-        connection_relationships = tool.Root.get_connection_relationships(objects_to_duplicate)
+        decomposition_relationships = tool.Duplicate.get_decomposition_relationships(objects_to_duplicate)
+        connection_relationships = tool.Duplicate.get_connection_relationships(objects_to_duplicate)
+        # Snapshot port-to-port connections — copy_class disconnects new ports
+        # by default, leaving Shift+D duplicates unconnected.
+        port_connection_snapshot = tool.Duplicate.get_port_connection_relationships(objects_to_duplicate)
         old_to_new: dict[ifcopenshell.entity_instance, list[ifcopenshell.entity_instance]] = {}
         old_obj_name_to_new_obj_name: dict[str, str] = {}
 
@@ -2155,10 +2283,7 @@ class Geometry(bonsai.core.tool.Geometry):
             keep_data_linked = linked and not element and not is_tracked_opening
 
             # Prior to duplicating, sync the object placement to make decomposition recreation more stable.
-            if tool.Ifc.is_moved(obj):
-                bonsai.core.geometry.edit_object_placement(
-                    tool.Ifc, tool.Geometry, tool.Surveyor, obj=obj, apply_scale=False
-                )
+            cls.commit_placement_if_moved(obj, apply_scale=False)
 
             new_obj = obj.copy()
             temp_data = None
@@ -2212,7 +2337,7 @@ class Geometry(bonsai.core.tool.Geometry):
                 array_data = arrays_to_duplicate.get(obj, None)
                 tool.Model.handle_array_on_copied_element(new, array_data)
                 if array_data:
-                    for child in tool.Blender.Modifier.Array.get_all_children_objects(new):
+                    for child in tool.Array.get_all_children_objects(new):
                         child.select_set(True)
 
                 # TODO: add new array children to recreate their decomposition too
@@ -2240,10 +2365,11 @@ class Geometry(bonsai.core.tool.Geometry):
 
         # Remove connections with old objects and recreates paths
         cls.remove_old_connections(old_to_new)
-        tool.Root.recreate_connections(connection_relationships, old_to_new)
+        tool.Duplicate.recreate_connections(connection_relationships, old_to_new)
+        tool.Duplicate.recreate_port_connections(port_connection_snapshot, old_to_new)
 
         # Recreate decompositions
-        tool.Root.recreate_decompositions(decomposition_relationships, old_to_new)
+        tool.Duplicate.recreate_decompositions(decomposition_relationships, old_to_new)
         cls.remove_linked_aggregate_data(old_to_new)
         bonsai.bim.handler.refresh_ui_data()
         tool.Root.reload_grid_decorator()
@@ -2308,8 +2434,8 @@ class Geometry(bonsai.core.tool.Geometry):
                 continue
 
             array_data = []
-            for modifier_data in tool.Blender.Modifier.Array.get_modifiers_data(array_parent):
-                children = set(tool.Blender.Modifier.Array.get_children_objects(modifier_data))
+            for modifier_data in tool.Array.get_modifiers_data(array_parent):
+                children = set(tool.Array.get_children_objects(modifier_data))
                 if children.issubset(selected_objects):
                     modifier_data["children"] = []
                     array_data.append(modifier_data)

src/bonsai/bonsai/tool/ifcgit.py

@@ -217,7 +217,7 @@ class IfcGit:
                 rev=[props.display_branch],
             )
         )
-        commits_relevant = list(
+        commits_relevant = set(
             git.objects.commit.Commit.iter_items(
                 repo=repo,
                 rev=[props.display_branch],
@@ -225,11 +225,17 @@ class IfcGit:
             )
         )
 
+        def is_relevant(commit):
+            if commit in commits_relevant:
+                return True
+            # Merge commits are relevant too
+            return len(commit.parents) > 1 and any(p in commits_relevant for p in commit.parents)
+
         for commit in commits:
 
             if props.ifcgit_filter == "tagged" and commit.hexsha not in lookup:
                 continue
-            elif props.ifcgit_filter == "relevant" and commit not in commits_relevant:
+            elif props.ifcgit_filter == "relevant" and not is_relevant(commit):
                 continue
 
             props.ifcgit_commits.add()
@@ -239,7 +245,7 @@ class IfcGit:
             list_item.author_name = commit.author.name
             list_item.author_email = commit.author.email
             list_item.committed_date = int(commit.committed_date)
-            if commit in commits_relevant:
+            if is_relevant(commit):
                 list_item.relevant = True
             if commit.hexsha in lookup:
                 for tag in lookup[commit.hexsha]:
@@ -280,11 +286,11 @@ class IfcGit:
             if re.match("^Ifc", obj.name):
                 bpy.data.objects.remove(obj, do_unlink=True)
 
-        bpy.data.orphans_purge(do_recursive=True)  # ty:ignore[unknown-argument]
+        bpy.data.orphans_purge(do_recursive=True)
 
-        from bonsai.bim.module.root.data import IfcClassData
-        from bonsai.bim.module.model.data import AuthoringData
         import bonsai.bim.handler
+        from bonsai.bim.module.model.data import AuthoringData
+        from bonsai.bim.module.root.data import IfcClassData
 
         AuthoringData.type_thumbnails = {}
 
@@ -589,7 +595,7 @@ class IfcGit:
         """Attempt a git merge. Returns None on clean merge, 'conflict' on expected
         GitCommandError, or 'error' on an unknown GitError."""
         repo = IfcGitRepo.repo
-        branch = repo.branches[branch_name]
+        branch = repo.refs[branch_name]
         try:
             repo.git.merge(branch)
             return None
@@ -603,7 +609,7 @@ class IfcGit:
         """Attempt a git merge without committing (always leaves a merge state to abort).
         Returns None on clean merge, 'conflict' on conflict, or 'error' on unknown failure."""
         repo = IfcGitRepo.repo
-        branch = repo.branches[branch_name]
+        branch = repo.refs[branch_name]
         try:
             repo.git.merge(branch, no_commit=True, no_ff=True)
             return None
@@ -619,8 +625,8 @@ class IfcGit:
         report_path = path_ifc + ".ifcmerge"
         try:
             repo.git.mergetool(tool=mergetool)
-        except git.exc.GitCommandError:
-            pass
+        except git.exc.GitCommandError as e:
+            print(f"ifcgit: mergetool failed: {e}")
 
         conflicts = None
         if os.path.exists(report_path):
@@ -636,6 +642,10 @@ class IfcGit:
                 os.remove(report_path)
             except OSError:
                 pass
+
+        if conflicts is None and repo.index.unmerged_blobs():
+            conflicts = []
+
         return conflicts
 
     @classmethod

src/bonsai/bonsai/tool/model.py

@@ -15,12 +15,14 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was modified with the assistance of an AI coding tool.
 
 from __future__ import annotations
 
 import collections.abc
 import json
-from collections.abc import Iterable, Sequence
+from collections.abc import Callable, Iterable, Sequence
 from copy import deepcopy
 from math import atan, cos, degrees, pi, radians
 from typing import (
@@ -37,9 +39,11 @@ from typing import (
 import bmesh
 import bpy
 import ifcopenshell
+import ifcopenshell.api.feature
 import ifcopenshell.api.geometry
 import ifcopenshell.api.grid
 import ifcopenshell.api.pset
+import ifcopenshell.api.root
 import ifcopenshell.geom
 import ifcopenshell.ifcopenshell_wrapper as W
 import ifcopenshell.util.element
@@ -58,6 +62,7 @@ import bonsai.core.geometry
 import bonsai.core.tool
 import bonsai.tool as tool
 from bonsai.bim import import_ifc
+from bonsai.tool.cad import VTX_PRECISION, WELD_TOLERANCE
 
 T = TypeVar("T")
 V_ = tool.Blender.V_
@@ -77,6 +82,7 @@ if TYPE_CHECKING:
         BIMRoofProperties,
         BIMStairProperties,
         BIMSverchokProperties,
+        BIMWallProperties,
         BIMWindowProperties,
     )
 
@@ -98,6 +104,10 @@ class Model(bonsai.core.tool.Model):
     def get_stair_props(cls, obj: bpy.types.Object) -> BIMStairProperties:
         return obj.BIMStairProperties  # pyright: ignore[reportAttributeAccessIssue]
 
+    @classmethod
+    def get_wall_props(cls, obj: bpy.types.Object) -> BIMWallProperties:
+        return obj.BIMWallProperties  # pyright: ignore[reportAttributeAccessIssue]
+
     @classmethod
     def get_roof_props(cls, obj: bpy.types.Object) -> BIMRoofProperties:
         return obj.BIMRoofProperties  # pyright: ignore[reportAttributeAccessIssue]
@@ -123,6 +133,35 @@ class Model(bonsai.core.tool.Model):
         assert (scene := bpy.context.scene)
         return scene.BIMPolylineProperties  # pyright: ignore[reportAttributeAccessIssue]
 
+    @classmethod
+    def resolve_active_props_for_edit(
+        cls,
+        context: bpy.types.Context,
+        props_getter: Callable[[bpy.types.Object], Any],
+        *,
+        subtype: Optional[tuple[str, Any]] = None,
+    ) -> Optional[tuple[bpy.types.Object, Any]]:
+        """Resolve ``(obj, props)`` for an operator that acts on the active
+        object only while a parametric edit is active.
+
+        Returns ``None`` (the operator should ``return {"CANCELLED"}``) when
+        any of these fail:
+        - no active object,
+        - ``props.is_editing`` is False,
+        - ``subtype`` is given as ``(attr, value)`` and ``props.<attr> != value``.
+        """
+        obj = context.active_object
+        if not obj:
+            return None
+        props = props_getter(obj)
+        if not getattr(props, "is_editing", False):
+            return None
+        if subtype is not None:
+            attr, value = subtype
+            if getattr(props, attr, None) != value:
+                return None
+        return obj, props
+
     @classmethod
     def convert_si_to_unit(cls, value: T) -> T:
         if isinstance(value, (tuple, list)):
@@ -792,7 +831,7 @@ class Model(bonsai.core.tool.Model):
         assert element or representation, "Either element or representation must be provided."
         if representation is None:
             assert element
-            representation = ifcopenshell.util.representation.get_representation(element, "Model", "Body", "MODEL_VIEW")
+            representation = tool.Geometry.get_body_representation(element)
             if not representation:
                 return []
         booleans = []
@@ -813,7 +852,7 @@ class Model(bonsai.core.tool.Model):
             return []
         boolean_ids = json.loads(pset["Data"])
         if representation is None:
-            representation = ifcopenshell.util.representation.get_representation(element, "Model", "Body", "MODEL_VIEW")
+            representation = tool.Geometry.get_body_representation(element)
             if not representation:
                 return []
         booleans = [b for b in cls.get_booleans(element, representation) if b.id() in boolean_ids]
@@ -902,7 +941,7 @@ class Model(bonsai.core.tool.Model):
                 # Revolved area check should happen inside bim.enable_editing_extrusion_axis
                 # but keep it here to trigger import_representation_items,
                 # so users will be able to at least move IfcRevolvedAreaSolid, until there will be a full support.
-                body = ifcopenshell.util.representation.get_representation(element, "Model", "Body", "MODEL_VIEW")
+                body = tool.Geometry.get_body_representation(element)
                 if body and any(
                     i.is_a("IfcRevolvedAreaSolid") for i in ifcopenshell.util.representation.resolve_base_items(body)
                 ):
@@ -1015,7 +1054,14 @@ class Model(bonsai.core.tool.Model):
     def handle_array_on_copied_element(
         cls, element: ifcopenshell.entity_instance, array_data: Optional[dict[str, Any]] = None
     ) -> None:
-        """if no `array_data` is provided then an array will be removed from the element"""
+        """Post-copy hook: decide what to do with the BBIM_Array pset a copy
+        inherits from its source.
+
+        - ``array_data=None`` — detach the copy from any array. Removes the
+          inherited BBIM_Array pset and any CHILD_OF constraint.
+        - ``array_data`` provided — promote the copy to a fresh array parent
+          with an empty children list, using the provided layer config.
+        """
 
         if array_data is None:
             array_pset = ifcopenshell.util.element.get_pset(element, "BBIM_Array")
@@ -1059,8 +1105,8 @@ class Model(bonsai.core.tool.Model):
             ifcopenshell.api.pset.edit_pset(tool.Ifc.get(), pset=array_pset, properties={"Data": json_data})
 
             for i in range(len(array_data)):
-                tool.Blender.Modifier.Array.set_children_lock_state(element, i, True)
-            tool.Blender.Modifier.Array.constrain_children_to_parent(element)
+                tool.Array.set_children_lock_state(element, i, True)
+            tool.Array.constrain_children_to_parent(element)
 
     @classmethod
     def regenerate_array(
@@ -1097,12 +1143,17 @@ class Model(bonsai.core.tool.Model):
                 offset = base_offset * i
 
                 for obj in obj_stack:
+                    # IndexError when child_i is past the recorded children list
+                    # (count grew); RuntimeError when by_guid finds no entity (the
+                    # child was deleted outside the array op); AssertionError when
+                    # the IFC entity exists but its Blender object was unlinked.
+                    # All three fall through to duplication.
                     try:
                         global_id = array["children"][child_i]
                         child_element = tool.Ifc.get().by_guid(global_id)
                         child_obj = tool.Ifc.get_object(child_element)
                         assert child_obj
-                    except:
+                    except (IndexError, RuntimeError, AssertionError):
                         old_to_new, _ = tool.Geometry.duplicate_ifc_objects([parent_obj])
                         child_element = next(iter(old_to_new.values()))[0]
                         child_obj = tool.Ifc.get_object(child_element)
@@ -1139,14 +1190,24 @@ class Model(bonsai.core.tool.Model):
             removed_children = set(existing_children) - set(array["children"])
             for removed_child in removed_children:
                 element = tool.Ifc.get().by_guid(removed_child)
+                # Strip any wall/slab opening cut by this child before deletion,
+                # so the host's HasOpenings shrinks symmetrically with count.
+                if getattr(element, "FillsVoids", None):
+                    ifcopenshell.api.feature.remove_feature(
+                        tool.Ifc.get(), feature=element.FillsVoids[0].RelatingOpeningElement
+                    )
                 obj = tool.Ifc.get_object(element)
                 if obj:
                     tool.Geometry.delete_ifc_object(obj)
 
+            if array.get("per_child_opening", array.get("mirror_to_host", True)) and children_elements:
+                cls.mirror_parent_void_fillings_to_children(parent_element, children_elements)
+
             if array_i in array_layers_to_apply:
                 for child_element in children_elements:
                     pset = tool.Pset.get_element_pset(child_element, "BBIM_Array")
                     ifcopenshell.api.pset.remove_pset(tool.Ifc.get(), product=child_element, pset=pset)
+                    cls.unshare_opening_representation(child_element)
 
                 array["children"] = []
                 array["count"] = 1
@@ -1159,6 +1220,112 @@ class Model(bonsai.core.tool.Model):
             tool.Ifc.get(), pset=pset, properties={"Data": json_data, "Parent": parent_element.GlobalId}
         )
 
+        # Post-condition: parent is selected on return. duplicate_ifc_objects
+        # deselects the source on every call inside the regen loop; without
+        # this restore, callers get a deselected parent for arrays with N >= 2.
+        # TODO: batch the per-child duplicate_ifc_objects([parent]) calls into
+        # a single N-way duplicate — N depsgraph churns + N select/deselect
+        # flips is wasteful, and a batched duplicate would also remove the
+        # need for this restore.
+        parent_obj.select_set(True)
+
+    @classmethod
+    def mirror_parent_void_fillings_to_children(
+        cls,
+        parent_element: ifcopenshell.entity_instance,
+        children_elements: Sequence[ifcopenshell.entity_instance],
+    ) -> None:
+        """Replicate the parent's FillsVoids → host chain onto each array child.
+
+        For each child, tears down any stale opening, creates a new
+        IfcOpeningElement at the child's current placement, reuses the parent's
+        opening representation as a MappedRepresentation, and adds the
+        void + filling pair so the host element is cut once per child.
+
+        No-op when the parent is not a filling, when the host element cannot
+        be resolved, or when the children list is empty. Opt out via the
+        per-layer ``per_child_opening`` flag on ``BBIM_Array.Data`` (legacy
+        key ``mirror_to_host`` still honoured for round-trip with older files).
+        """
+        host = tool.Spatial.get_host_element(parent_element)
+        if host is None or not children_elements:
+            return
+
+        ifc_file = tool.Ifc.get()
+        parent_opening = parent_element.FillsVoids[0].RelatingOpeningElement
+        parent_opening_rep = ifcopenshell.util.representation.get_representation(
+            parent_opening, "Model", "Body", "MODEL_VIEW"
+        )
+        if parent_opening_rep is None:
+            return
+        parent_opening_rep = ifcopenshell.util.representation.resolve_representation(parent_opening_rep)
+
+        for child in children_elements:
+            if getattr(child, "FillsVoids", None):
+                ifcopenshell.api.feature.remove_feature(ifc_file, feature=child.FillsVoids[0].RelatingOpeningElement)
+            child_obj = tool.Ifc.get_object(child)
+            if child_obj is None:
+                continue
+
+            new_opening = ifcopenshell.api.root.create_entity(
+                ifc_file,
+                ifc_class="IfcOpeningElement",
+                predefined_type="OPENING",
+                name="Opening",
+            )
+            ifcopenshell.api.geometry.edit_object_placement(
+                ifc_file,
+                product=new_opening,
+                matrix=np.array(child_obj.matrix_world),
+                is_si=True,
+            )
+            mapped_representation = ifcopenshell.api.geometry.map_representation(
+                ifc_file, representation=parent_opening_rep
+            )
+            ifcopenshell.api.geometry.assign_representation(
+                ifc_file, product=new_opening, representation=mapped_representation
+            )
+            ifcopenshell.api.feature.add_feature(ifc_file, feature=new_opening, element=host)
+            ifcopenshell.api.feature.add_filling(ifc_file, opening=new_opening, element=child)
+
+        # Openings affect every sub-element of an aggregate, not just the named host.
+        voided_objs: list[bpy.types.Object] = []
+        host_obj = tool.Ifc.get_object(host)
+        if host_obj is not None:
+            voided_objs.append(host_obj)
+        for subelement in tool.Aggregate.get_parts_recursively(host):
+            subobj = tool.Ifc.get_object(subelement)
+            if subobj is not None:
+                voided_objs.append(subobj)
+
+        for voided_obj in voided_objs:
+            if not voided_obj.data:
+                continue
+            voided_element = tool.Ifc.get_entity(voided_obj)
+            if voided_element is None:
+                continue
+            context = tool.Geometry.get_active_representation_context(voided_obj)
+            representation = tool.Geometry.get_representation_by_context(voided_element, context)
+            if representation is None:
+                continue
+            bonsai.core.geometry.switch_representation(
+                tool.Ifc, tool.Geometry, obj=voided_obj, representation=representation
+            )
+
+    @classmethod
+    def unshare_opening_representation(cls, filling: ifcopenshell.entity_instance) -> None:
+        """Detach a filling's opening representation from any shared mapped body.
+
+        Required when a Bonsai array child is promoted to an independent
+        object: the array's per-child opening mirror builds each child's
+        opening representation as an ``IfcMappedRepresentation`` over the
+        parent opening's body. Without this detach, a later edit replacing
+        the parent body rewrites the shared ``IfcRepresentationMap`` and
+        reshapes the former-child's opening too."""
+        if not getattr(filling, "FillsVoids", None):
+            return
+        tool.Geometry.detach_representation(filling.FillsVoids[0].RelatingOpeningElement)
+
     @classmethod
     def replace_object_ifc_representation(
         cls,
@@ -1305,8 +1472,8 @@ class Model(bonsai.core.tool.Model):
         return [obj for obj in tool.Blender.get_selected_objects() if tool.Ifc.get_entity(obj)]
 
     @classmethod
-    def has_selected_ifc_objects(cls) -> bool:
-        return any(tool.Ifc.get_entity(obj) for obj in tool.Blender.get_selected_objects())
+    def has_selected_ifc_objects(cls, include_active: bool = True) -> bool:
+        return any(tool.Ifc.get_entity(obj) for obj in tool.Blender.get_selected_objects(include_active=include_active))
 
     @classmethod
     def get_selected_mesh_objects(cls) -> list[bpy.types.Object]:
@@ -1355,8 +1522,7 @@ class Model(bonsai.core.tool.Model):
     @classmethod
     def sync_object_ifc_position(cls, obj: bpy.types.Object) -> None:
         """make sure IFC position will be in sync with the Blender object position, if object was moved in Blender"""
-        if tool.Ifc.is_moved(obj):
-            bonsai.core.geometry.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=obj)
+        tool.Geometry.commit_placement_if_moved(obj)
 
     @classmethod
     def get_element_matrix(cls, element: ifcopenshell.entity_instance, keep_local: bool = False) -> Matrix:
@@ -1388,7 +1554,7 @@ class Model(bonsai.core.tool.Model):
             if not obj.data:
                 continue
             element = tool.Ifc.get_entity(obj)
-            body = ifcopenshell.util.representation.get_representation(element, "Model", "Body", "MODEL_VIEW")
+            body = tool.Geometry.get_body_representation(element)
             bonsai.core.geometry.switch_representation(
                 tool.Ifc,
                 tool.Geometry,
@@ -1505,6 +1671,10 @@ class Model(bonsai.core.tool.Model):
         "TRIPLE_PANEL_VERTICAL",
     ]
 
+    RoofGenerationMethod = Literal["HEIGHT", "ANGLE"]
+
+    RailingType = Literal["FRAMELESS_PANEL", "WALL_MOUNTED_HANDRAIL"]
+
     @classmethod
     def generate_stair_2d_profile(
         cls,
@@ -1756,7 +1926,7 @@ class Model(bonsai.core.tool.Model):
         from bonsai.bim.module.model.opening import FilledOpeningGenerator
 
         ifc_file = tool.Ifc.get()
-        fillings = {e: tool.Ifc.get_object(e) for e in tool.Ifc.get_all_element_occurrences(element)}
+        fillings = {e: tool.Ifc.get_object(e) for e in tool.Array.get_parametric_propagation_targets(element)}
 
         voided_objs = set()
         has_replaced_opening_representation = False
@@ -1898,7 +2068,9 @@ class Model(bonsai.core.tool.Model):
 
         bm = bmesh.new()
         bm.from_mesh(mesh)
-        bmesh.ops.remove_doubles(bm, verts=bm.verts, dist=1e-4)
+        # Looser than auto_detect_curves' VTX_PRECISION: profiles must close into
+        # a single loop, so nearly-coincident endpoints should snap together.
+        bmesh.ops.remove_doubles(bm, verts=bm.verts, dist=WELD_TOLERANCE)
         bmesh.ops.delete(bm, geom=bm.faces, context="FACES_ONLY")
 
         # https://docs.blender.org/api/blender_python_api_2_63_8/bmesh.html#CustomDataAccess
@@ -2126,7 +2298,7 @@ class Model(bonsai.core.tool.Model):
 
         bm = bmesh.new()
         bm.from_mesh(mesh)
-        bmesh.ops.remove_doubles(bm, verts=bm.verts, dist=1e-5)
+        bmesh.ops.remove_doubles(bm, verts=bm.verts, dist=VTX_PRECISION)
         bmesh.ops.delete(bm, geom=bm.faces, context="FACES_ONLY")
 
         # https://docs.blender.org/api/blender_python_api_2_63_8/bmesh.html#CustomDataAccess
@@ -2345,6 +2517,12 @@ class Model(bonsai.core.tool.Model):
 
     @classmethod
     def get_existing_x_angle(cls, extrusion: ifcopenshell.entity_instance) -> float:
+        """Signed slope of the extrusion's direction in the y-z plane (radians).
+
+        Assumes extrusion directions lie in the y-z plane (LAYER2 wall and
+        LAYER3 slab convention). For inverted extrusions (z ≤ 0), adds π to
+        preserve angular continuity for callers consuming the angle via
+        cos/sin."""
         x, y, z = extrusion.ExtrudedDirection.DirectionRatios
         vector = Vector((0, 1))
         x_angle = vector.angle_signed(Vector((y, z)))
@@ -2693,6 +2871,10 @@ class Model(bonsai.core.tool.Model):
 
     @classmethod
     def recreate_wall(cls, element: ifcopenshell.entity_instance, obj: bpy.types.Object) -> None:
+        # FIXME(PR4): the fillet-corner branch lands with PR4's
+        # `regenerate_fillet_corner_wall` (bim/module/model/wall.py). On v0.8.0
+        # the function doesn't exist; falling through to the straight-extrusion
+        # path preserves v0.8.0 behaviour for fillet walls until PR4 ships.
         rep = ifcopenshell.api.geometry.regenerate_wall_representation(tool.Ifc.get(), element)
         bonsai.core.geometry.switch_representation(
             tool.Ifc,
@@ -2713,28 +2895,29 @@ class Model(bonsai.core.tool.Model):
         queue: set[tuple[ifcopenshell.entity_instance, bpy.types.Object]] = set()
         for wall in walls:
             element = tool.Ifc.get_entity(wall)
-            if tool.Ifc.is_moved(wall):
-                bonsai.core.geometry.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=wall)
+            tool.Geometry.commit_placement_if_moved(wall)
             queue.add((element, wall))
             for rel in getattr(element, "ConnectedTo", []):
                 obj = tool.Ifc.get_object(rel.RelatedElement)
-                if tool.Ifc.is_moved(obj):
-                    bonsai.core.geometry.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=obj)
+                tool.Geometry.commit_placement_if_moved(obj)
                 queue.add((rel.RelatedElement, obj))
             for rel in getattr(element, "ConnectedFrom", []):
                 obj = tool.Ifc.get_object(rel.RelatingElement)
-                if tool.Ifc.is_moved(obj):
-                    bonsai.core.geometry.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=obj)
+                tool.Geometry.commit_placement_if_moved(obj)
                 queue.add((rel.RelatingElement, obj))
         for element, wall in queue:
-            if tool.Model.get_usage_type(element) == "LAYER2" and wall:
-                # Use layer custom offset
+            if not wall:
+                continue
+            is_layer2_usage = tool.Model.get_usage_type(element) == "LAYER2"
+            is_fillet_corner = bool(ifcopenshell.util.element.get_pset(element, "BBIM_Wall", "IsFilletCorner"))
+            if not (is_layer2_usage or is_fillet_corner):
+                continue
+            if is_layer2_usage:
                 custom_offset = tool.Model.get_material_layer_custom_offset(element, wall)
                 material = ifcopenshell.util.element.get_material(element)
                 if material.is_a("IfcMaterialLayerSetUsage") and custom_offset is not None:
                     material.OffsetFromReferenceLine = custom_offset
-
-                cls.recreate_wall(element, wall)
+            cls.recreate_wall(element, wall)
 
     @classmethod
     def regenerate_slab(cls, obj: bpy.types.Object) -> None:

src/bonsai/bonsai/tool/parametric.py

@@ -0,0 +1,616 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2026
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was generated with the assistance of an AI coding tool.
+
+"""Registry and save-time auto-commit for parametric draft edits.
+
+The registry is consumed along two orthogonal axes:
+
+- **Predicate axis**: every entry carries an ``is_<name>`` total predicate. Used
+  by ``find_for_element``, save-flow auto-commit, and per-feature gizmo polls.
+- **Lifecycle axis**: a subset of entries flagged ``supports_build_edit_lifecycle=True``
+  share the ``Enable/Finish/CancelEditing<Type>`` operator shape and are wired
+  through ``build_edit_lifecycle``. The remainder declare their edit operators
+  directly because their lifecycle (per-attribute diff dispatch, layer-stack
+  editing, mid-spline gizmo drag, …) does not fit the shared mixin contract.
+
+Adding a new parametric element type is a single entry in ``EDIT_TYPES``;
+flag ``supports_build_edit_lifecycle`` only if the type's edit lifecycle matches
+one of the shared mixins in ``bim/parametric_lifecycle.py``."""
+
+from __future__ import annotations
+
+import logging
+import re
+from collections.abc import Callable
+from dataclasses import dataclass
+from typing import TYPE_CHECKING, Any, ClassVar, Optional
+
+import bpy
+
+import bonsai.core.tool
+import bonsai.tool as tool
+
+logger = logging.getLogger(__name__)
+
+if TYPE_CHECKING:
+    from ifcopenshell import entity_instance
+
+
+# Lowercase ASCII snake_case token; each segment a non-empty letter/digit
+# sequence starting with a letter. ``"pipe_segment"`` → ``"BIMPipeSegmentProperties"``.
+_VALID_NAME_RE = re.compile(r"^[a-z][a-z0-9]*(?:_[a-z0-9]+)*$")
+
+
+def _camel_case(name: str) -> str:
+    return "".join(part.capitalize() for part in name.split("_"))
+
+
+@dataclass(frozen=True)
+class ParametricObject:
+    """One parametric element type's draft + enable + finish + cancel edit lifecycle.
+
+    The ``name`` token drives every derived identifier: the
+    ``BIM<Name>Properties`` attribute on ``bpy.types.Object``, the
+    ``bim.enable_editing_<name>`` / ``bim.finish_editing_<name>`` /
+    ``bim.cancel_editing_<name>`` operator ``bl_idname``s, and the
+    ``tool.Parametric.is_<name>`` runtime predicate.
+
+    The predicate is part of the contract and MUST be total — accept any IFC
+    entity, return a bool, never raise. A raising predicate breaks the save
+    path for every parametric type, not just its own.
+
+    ``supports_build_edit_lifecycle`` marks entries whose edit lifecycle fits the
+    shared mixin contract (``_enable_targets`` / ``_finish_targets`` /
+    ``_cancel_targets``) and that therefore wire their operators through
+    ``build_edit_lifecycle``. Entries with bespoke edit lifecycles (per-attribute
+    diff dispatch, layer-stack editing, mid-spline gizmo drag) leave this
+    False and declare their operator classes directly."""
+
+    name: str
+    has_non_editable_path: bool = False
+    supports_build_edit_lifecycle: bool = False
+
+    def __post_init__(self) -> None:
+        if not _VALID_NAME_RE.match(self.name):
+            raise ValueError(
+                f"ParametricObject name {self.name!r} must match "
+                f"{_VALID_NAME_RE.pattern!r} — lowercase letters / digits, "
+                f"optionally split by single underscores (e.g. ``door`` or "
+                f"``pipe_segment``). Leading / trailing underscores and "
+                f"consecutive underscores are rejected because they produce "
+                f"empty CamelCase segments in derived class names."
+            )
+
+    @property
+    def props_attr(self) -> str:
+        return f"BIM{_camel_case(self.name)}Properties"
+
+    @property
+    def enable_op(self) -> str:
+        return f"bim.enable_editing_{self.name}"
+
+    @property
+    def finish_op(self) -> str:
+        return f"bim.finish_editing_{self.name}"
+
+    @property
+    def cancel_op(self) -> str:
+        return f"bim.cancel_editing_{self.name}"
+
+    def is_editing(self, obj: bpy.types.Object) -> bool:
+        props = getattr(obj, self.props_attr, None)
+        return bool(props and getattr(props, "is_editing", False))
+
+
+class Parametric(bonsai.core.tool.Parametric):
+    class GenerationKeyedCache:
+        """A dict-keyed cache stamped with the parametric generation counter
+        at fill time. Reads at a later generation drop the whole dict and
+        re-run the loader. Any IFC commit bumps the generation, invalidating
+        all entries en bloc.
+
+        ``None`` values are stored verbatim; only "key not in dict" counts as
+        a miss."""
+
+        def __init__(self) -> None:
+            self._gen: int | None = None
+            self._data: dict = {}
+
+        def get_or_compute(self, key, loader):
+            current = Parametric.get_geom_generation()
+            if self._gen != current:
+                self._data.clear()
+                self._gen = current
+            if key not in self._data:
+                self._data[key] = loader()
+            return self._data[key]
+
+        def clear(self) -> None:
+            """Explicit drop. Use from ``load_post`` so a fresh file starts clean."""
+            self._data.clear()
+            self._gen = None
+
+    # FIXME(PR4): array / pipe_segment / duct_segment land with their
+    # finish/cancel operators in PR4. Adding them to EDIT_TYPES without those
+    # operators makes auto-commit-on-save dispatch bim.finish_editing_<name>
+    # for objects flagged as in-edit, which then raises because the operator
+    # doesn't exist. PR4 re-adds the three entries together with the operators.
+    EDIT_TYPES: list[ParametricObject] = [
+        ParametricObject("door", has_non_editable_path=True, supports_build_edit_lifecycle=True),
+        ParametricObject("window", has_non_editable_path=True, supports_build_edit_lifecycle=True),
+        ParametricObject("stair", has_non_editable_path=True, supports_build_edit_lifecycle=True),
+        ParametricObject("railing", supports_build_edit_lifecycle=True),
+        ParametricObject("roof", supports_build_edit_lifecycle=True),
+        ParametricObject("wall"),
+    ]
+
+    # Annotations for the uppercase constants populated from ``EDIT_TYPES`` by
+    # the binding loop at module bottom. Declared here so IDEs and type
+    # checkers see the attributes without running the loop.
+    DOOR: ClassVar[ParametricObject]
+    WINDOW: ClassVar[ParametricObject]
+    STAIR: ClassVar[ParametricObject]
+    RAILING: ClassVar[ParametricObject]
+    ROOF: ClassVar[ParametricObject]
+    WALL: ClassVar[ParametricObject]
+
+    _geom_generation: int = 0
+
+    @classmethod
+    def get_geom_generation(cls) -> int:
+        return cls._geom_generation
+
+    @classmethod
+    def refresh_post_commit(cls) -> None:
+        """Post-commit hook for ``tool.Ifc.Operator``: re-syncs scene-level
+        workspace-tool header fields from current IFC state and bumps the
+        geometry generation counter so caches keyed off it drop stale
+        entries on the next draw."""
+        import bonsai.bim.handler  # late import: bim.handler imports tool.*
+
+        cls._geom_generation += 1
+        bonsai.bim.handler.update_bim_tool_props()
+        tool.Blender.update_all_viewports()
+
+    @classmethod
+    def find_by_name(cls, name: str) -> Optional[ParametricObject]:
+        return next((f for f in cls.EDIT_TYPES if f.name == name), None)
+
+    @classmethod
+    def _safe_predicate(cls, feature: ParametricObject, element: entity_instance) -> bool:
+        """Resolve and invoke ``is_<feature.name>`` defensively. The contract is
+        that predicates are total (see ``ParametricObject`` docstring); a
+        regression that turns one predicate raising would otherwise break the
+        save path for every parametric type, not just its own."""
+        predicate = getattr(cls, f"is_{feature.name}", None)
+        if predicate is None:
+            return False
+        try:
+            return bool(predicate(element))
+        except Exception:
+            logger.warning(
+                "parametric predicate is_%s raised on %r",
+                feature.name,
+                element,
+                exc_info=True,
+            )
+            return False
+
+    @classmethod
+    def find_for_element(cls, element: entity_instance) -> Optional[ParametricObject]:
+        """Return the registry entry whose IFC type predicate matches ``element``."""
+        for feature in cls.EDIT_TYPES:
+            if cls._safe_predicate(feature, element):
+                return feature
+        return None
+
+    @classmethod
+    def is_object_editing(cls, obj: bpy.types.Object, skip_name: Optional[str] = None) -> Optional[ParametricObject]:
+        """Return the registry entry whose edit lifecycle is active on ``obj``, or None.
+
+        ``skip_name`` excludes one entry from the scan, for callers that want
+        to know if a *different* type is editing."""
+        for feature in cls.EDIT_TYPES:
+            if feature.name == skip_name:
+                continue
+            if feature.is_editing(obj):
+                return feature
+        return None
+
+    @classmethod
+    def _validated_editing_feature(cls, obj: bpy.types.Object) -> Optional[ParametricObject]:
+        """Return the active registry entry on ``obj``, validated against the
+        per-type predicate. Returns None when no ``is_editing`` flag is set
+        or when the flag is stale.
+
+        Self-heals: a predicate mismatch clears the flag in place so the
+        finish dispatch never re-picks up a phantom edit."""
+        feature = cls.is_object_editing(obj)
+        if feature is None:
+            return None
+        element = tool.Ifc.get_entity(obj)
+        if element is None or not cls._safe_predicate(feature, element):
+            getattr(obj, feature.props_attr).is_editing = False
+            return None
+        return feature
+
+    @classmethod
+    def heal_stale_edit_flags(cls) -> None:
+        """Validate every scene object's ``is_editing`` flag against the
+        per-type predicate, clearing stale flags in place.
+
+        Run from ``load_post`` so a ``.blend`` saved with phantom flags
+        (e.g. a save that bypassed the auto-commit flush) is consistent the
+        moment it opens."""
+        for obj in bpy.data.objects:
+            cls._validated_editing_feature(obj)
+
+    @classmethod
+    def get_pending_edits(cls) -> list[tuple[bpy.types.Object, str]]:
+        """``(object, finish_operator_bl_idname)`` pairs for every object
+        with an in-progress parametric draft. Stale flags are cleared in
+        place and excluded."""
+        pending: list[tuple[bpy.types.Object, str]] = []
+        for obj in bpy.data.objects:
+            feature = cls._validated_editing_feature(obj)
+            if feature is not None:
+                pending.append((obj, feature.finish_op))
+        return pending
+
+    @classmethod
+    def run_bim_op(cls, bl_idname: str) -> None:
+        """Invoke a ``bim.*`` operator by ``bl_idname``.
+
+        Asserts the operator is a ``tool.Ifc.Operator`` subclass — bypassing
+        that wrap would mutate IFC outside Bonsai's transaction system."""
+        verb = bl_idname.removeprefix("bim.")
+        op_cls = getattr(bpy.types, f"BIM_OT_{verb}", None)
+        if op_cls is None or not issubclass(op_cls, tool.Ifc.Operator):
+            raise RuntimeError(
+                f"{bl_idname!r} must be a registered tool.Ifc.Operator subclass for undo-safe IFC mutation"
+            )
+        getattr(bpy.ops.bim, verb)()
+
+    @classmethod
+    def commit_object_draft(cls, obj: bpy.types.Object, finish_op: str) -> bool:
+        """Run ``finish_op`` scoped to ``obj`` alone. Returns False (with
+        traceback printed) if the operator raised.
+
+        Both ``temp_override`` and ``view_layer.objects.active`` are set:
+        ``temp_override`` does not rebind ``objects.active``, and some finish
+        operators read it directly."""
+        view_layer = bpy.context.view_layer
+        original_active = view_layer.objects.active
+        try:
+            with bpy.context.temp_override(active_object=obj, selected_objects=[obj]):
+                view_layer.objects.active = obj
+                try:
+                    cls.run_bim_op(finish_op)
+                    return True
+                except Exception:
+                    logger.warning(
+                        "commit of %r via %s failed",
+                        obj.name,
+                        finish_op,
+                        exc_info=True,
+                    )
+                    return False
+        finally:
+            view_layer.objects.active = original_active
+
+    @classmethod
+    def commit_pending_edits(cls) -> tuple[int, list[bpy.types.Object]]:
+        """Run each pending draft's finish operator scoped to its object.
+
+        A per-object failure does not abort the loop — remaining drafts
+        still flush, otherwise the auto-commit would ship the exact silent
+        desync it exists to prevent."""
+        committed = 0
+        failed: list[bpy.types.Object] = []
+        for obj, finish_op in cls.get_pending_edits():
+            if cls.commit_object_draft(obj, finish_op):
+                committed += 1
+            else:
+                failed.append(obj)
+        return committed, failed
+
+    @classmethod
+    def commit_pending_edits_for_selection(
+        cls, names: Optional[tuple[str, ...]] = None
+    ) -> tuple[int, list[bpy.types.Object]]:
+        """Selection-scoped variant. ``names`` filters which registry entries
+        to consider; ``None`` considers every type."""
+        committed = 0
+        failed: list[bpy.types.Object] = []
+        for obj in tool.Blender.get_selected_objects():
+            feature = cls._validated_editing_feature(obj)
+            if feature is None:
+                continue
+            if names is not None and feature.name not in names:
+                continue
+            if cls.commit_object_draft(obj, feature.finish_op):
+                committed += 1
+            else:
+                failed.append(obj)
+        return committed, failed
+
+    @classmethod
+    def _assert_predicates_registered(cls) -> None:
+        """Loud at addon-enable if any ``EDIT_TYPES`` entry has no matching
+        ``is_<name>`` classmethod. Without this, a typo in the registry entry
+        produces a silent-False predicate that never matches — every
+        parametric draft of that type bypasses save-flow auto-commit."""
+        missing = [feature.name for feature in cls.EDIT_TYPES if not callable(getattr(cls, f"is_{feature.name}", None))]
+        if missing:
+            raise RuntimeError(
+                f"tool.Parametric.EDIT_TYPES has entries with no is_<name> predicate: {missing}. "
+                f"Add `is_<name>(cls, element) -> bool` classmethods on tool.Parametric, "
+                f"or remove the entries from EDIT_TYPES."
+            )
+
+    @classmethod
+    def register_object_properties(cls, prop_module) -> None:
+        """Attach ``bpy.types.Object.BIM<Name>Properties`` for every registered
+        parametric type. Skips entries whose ``PropertyGroup`` is absent."""
+        cls._assert_predicates_registered()
+        for feature in cls.EDIT_TYPES:
+            prop_cls = getattr(prop_module, feature.props_attr, None)
+            if prop_cls is None:
+                continue
+            setattr(bpy.types.Object, feature.props_attr, bpy.props.PointerProperty(type=prop_cls))
+
+    @classmethod
+    def unregister_object_properties(cls) -> None:
+        for feature in cls.EDIT_TYPES:
+            if hasattr(bpy.types.Object, feature.props_attr):
+                delattr(bpy.types.Object, feature.props_attr)
+
+    @classmethod
+    def iter_gizmo_preference_classes(cls, ui_module) -> list[type]:
+        """``GizmoPreferences<Name>`` classes that exist on ``ui_module`` for
+        every registry entry, plus the shared ``GizmoPreferencesFeature`` if
+        present. Order matches ``EDIT_TYPES``. Used by ``bim/__init__.py`` to
+        inject the per-type ``GizmoPreferences<X>`` classes at the correct
+        point — before ``ui.GizmoPreferences``, which references them via
+        ``PointerProperty``."""
+        # FIXME(PR5): drop the per-feature loop once PR4 consolidates
+        # bim/ui.py to use a single shared GizmoPreferencesFeature class
+        # and rewrites GizmoPreferences accordingly. The shared-class
+        # branch is the forward-compat path; the per-feature loop keeps
+        # v0.8.0's bim/ui.py working until then.
+        out: list[type] = []
+        for feature in cls.EDIT_TYPES:
+            gpref = getattr(ui_module, f"GizmoPreferences{feature.name.capitalize()}", None)
+            if gpref is not None:
+                out.append(gpref)
+        shared = getattr(ui_module, "GizmoPreferencesFeature", None)
+        if shared is not None:
+            out.append(shared)
+        return out
+
+    # --- Feature-kind predicates ------------------------------------------------
+    # One predicate per registered parametric type. Each is total: accepts any
+    # IFC entity (or None), returns a bool, never raises. Predicates live with
+    # the registry rather than ``tool.Blender.Modifier`` because they ARE the
+    # registry contract — ``find_for_element`` and ``_validated_editing_feature``
+    # resolve them by name. Coupling them on the same class makes a typo at
+    # registration time an immediate AttributeError instead of a silent None
+    # predicate that never matches.
+
+    @classmethod
+    def is_array(cls, element: entity_instance) -> bool:
+        """True if element is the PARENT of a Bonsai parametric array.
+
+        Array children also carry a ``BBIM_Array`` pset (their ``Parent``
+        field points back to the original), so checking pset presence alone
+        would falsely match them. The parent is distinguished by
+        ``pset.Parent == element.GlobalId``."""
+        import ifcopenshell.util.element
+
+        if element is None:
+            return False
+        pset = ifcopenshell.util.element.get_pset(element, "BBIM_Array")
+        if not pset:
+            return False
+        return pset.get("Parent") == element.GlobalId
+
+    @classmethod
+    def is_railing(cls, element: entity_instance) -> bool:
+        if element is None:
+            return False
+        return tool.Pset.get_element_pset(element, "BBIM_Railing") is not None
+
+    @classmethod
+    def is_roof(cls, element: entity_instance) -> bool:
+        if element is None:
+            return False
+        return tool.Pset.get_element_pset(element, "BBIM_Roof") is not None
+
+    @classmethod
+    def is_window(cls, element: entity_instance) -> bool:
+        if element is None:
+            return False
+        return tool.Pset.get_element_pset(element, "BBIM_Window") is not None
+
+    @classmethod
+    def is_door(cls, element: entity_instance) -> bool:
+        if element is None:
+            return False
+        return tool.Pset.get_element_pset(element, "BBIM_Door") is not None
+
+    @classmethod
+    def is_stair(cls, element: entity_instance) -> bool:
+        if element is None:
+            return False
+        return tool.Pset.get_element_pset(element, "BBIM_Stair") is not None
+
+    @classmethod
+    def is_wall(cls, element: entity_instance) -> bool:
+        """A wall is editable by the parametric gizmo if it is an IfcWall with LAYER2 usage.
+
+        Unlike doors/windows/stairs, walls do not carry a proprietary BBIM_Wall pset —
+        their parametric state lives in standard IFC (axis polyline, IfcMaterialLayerSetUsage,
+        IfcExtrudedAreaSolid). Any LAYER2 wall qualifies."""
+        if element is None or not element.is_a("IfcWall"):
+            return False
+        return tool.Model.get_usage_type(element) == "LAYER2"
+
+    @classmethod
+    def is_path_connectable_wall(cls, element: entity_instance) -> bool:
+        """An IfcWall that may participate in IfcRelConnectsPathElements joins —
+        either a LAYER2 parametric wall, or a fillet-corner wall whose body is
+        hand-built but whose axis still drives path connections.
+
+        Distinct from ``is_wall``: that predicate gates parametric edits that
+        would regenerate the body and flatten a curved fillet. Unjoin / join
+        gizmo polls and path-connection partner enumeration use this looser
+        predicate so fillet corners (which have no LAYER2 usage by spec) still
+        surface their join icons."""
+        if element is None or not element.is_a("IfcWall"):
+            return False
+        if tool.Model.get_usage_type(element) == "LAYER2":
+            return True
+        import ifcopenshell.util.element
+
+        return bool(ifcopenshell.util.element.get_pset(element, "BBIM_Wall", "IsFilletCorner"))
+
+    @classmethod
+    def is_pipe_segment(cls, element: entity_instance) -> bool:
+        return element is not None and element.is_a("IfcPipeSegment")
+
+    @classmethod
+    def is_duct_segment(cls, element: entity_instance) -> bool:
+        return element is not None and element.is_a("IfcDuctSegment")
+
+    @classmethod
+    def build_edit_lifecycle(
+        cls,
+        feature_name: str,
+        mixin: type,
+        labels: tuple[tuple[str, str], tuple[str, str], tuple[str, str]],
+        bl_options: Optional[set[str]] = None,
+        enable_extra_props: Optional[dict[str, Any]] = None,
+        enable_extra_kwargs: Optional[Callable[[Any], dict[str, Any]]] = None,
+        module_name: Optional[str] = None,
+    ) -> tuple[type, type, type]:
+        """Generate (Enable, Finish, Cancel) operator classes for a parametric type.
+
+        ``mixin`` provides ``_enable_targets`` / ``_finish_targets`` /
+        ``_cancel_targets`` (i.e. inherits from ``ParametricEditMixinBase`` or
+        a sibling). ``labels`` is ``((enable_label, enable_desc), …)`` in
+        Enable / Finish / Cancel order.
+
+        ``bl_idname`` and the Python class name come from the registry entry —
+        ``feature_name`` MUST already be in ``EDIT_TYPES``, otherwise a typo
+        produces an unregistered operator. Anchoring bl_idnames to the registry
+        eliminates the silent-mismatch failure mode where a hand-typed
+        ``bl_idname = "bim.enable_editing_dor"`` produces a class that
+        ``find_for_element`` never resolves to.
+
+        ``enable_extra_props`` declares extra ``bpy.props.*`` descriptors to
+        attach to the Enable class only (e.g. array's ``item: IntProperty``
+        carrying the target layer index across redo). When set,
+        ``enable_extra_kwargs`` must also be supplied: it receives the Enable
+        operator instance and returns a kwargs dict forwarded to
+        ``_enable_targets`` so the mixin's enable phase sees the extras.
+
+        ``module_name`` sets ``__module__`` on the generated classes — pass
+        ``__name__`` from the calling feature module so Blender's right-click
+        → Edit Source resolves to the feature module rather than the factory
+        site. Defaults to the factory's module, which is sub-optimal for
+        debugging but harmless."""
+        import bonsai.tool as _tool  # late import: tool/__init__.py wires this module last
+
+        feature = cls.find_by_name(feature_name)
+        if feature is None:
+            raise RuntimeError(
+                f"build_edit_lifecycle: {feature_name!r} not in EDIT_TYPES — add a "
+                f"ParametricObject entry before declaring its operators"
+            )
+        if not feature.supports_build_edit_lifecycle:
+            raise RuntimeError(
+                f"build_edit_lifecycle: {feature_name!r} has supports_build_edit_lifecycle=False — "
+                f"its edit lifecycle is bespoke. Either declare "
+                f"Enable/Finish/CancelEditing{_camel_case(feature_name)} as direct Operator "
+                f"subclasses, or flip the flag on the EDIT_TYPES entry if the type does fit "
+                f"the shared mixin contract."
+            )
+        if (enable_extra_props is None) != (enable_extra_kwargs is None):
+            raise RuntimeError(
+                f"build_edit_lifecycle({feature_name!r}): enable_extra_props and "
+                f"enable_extra_kwargs must be supplied together — extras with no "
+                f"kwargs builder are unreachable, kwargs with no extras have nothing to forward"
+            )
+        options = bl_options if bl_options is not None else {"REGISTER", "UNDO"}
+        base_classes = (mixin, bpy.types.Operator, _tool.Ifc.Operator)
+        capitalised = _camel_case(feature_name)
+
+        def _build(
+            action: str, bl_idname: str, label: str, desc: str, target_method: str, extras: Optional[dict]
+        ) -> type:
+            if extras and target_method == "_enable_targets":
+                assert enable_extra_kwargs is not None
+                kwargs_builder = enable_extra_kwargs
+
+                def _execute(self, context: bpy.types.Context) -> set[str]:
+                    return getattr(self, target_method)(context, **kwargs_builder(self))
+
+            else:
+
+                def _execute(self, context: bpy.types.Context) -> set[str]:
+                    return getattr(self, target_method)(context)
+
+            attrs: dict[str, Any] = {
+                "bl_idname": bl_idname,
+                "bl_label": label,
+                "bl_description": desc,
+                "bl_options": options,
+                "_execute": _execute,
+            }
+            if module_name is not None:
+                attrs["__module__"] = module_name
+            if extras:
+                # Blender's PropertyGroup machinery reads __annotations__ for bpy.props descriptors.
+                attrs["__annotations__"] = dict(extras)
+            return type(f"{action}Editing{capitalised}", base_classes, attrs)
+
+        return (
+            _build("Enable", feature.enable_op, labels[0][0], labels[0][1], "_enable_targets", enable_extra_props),
+            _build("Finish", feature.finish_op, labels[1][0], labels[1][1], "_finish_targets", None),
+            _build("Cancel", feature.cancel_op, labels[2][0], labels[2][1], "_cancel_targets", None),
+        )
+
+
+_edit_type_names = [entry.name for entry in Parametric.EDIT_TYPES]
+if len(set(_edit_type_names)) != len(_edit_type_names):
+    raise RuntimeError(
+        f"EDIT_TYPES name collision: {_edit_type_names}. Each name is the primary key "
+        f"for derived bl_idnames, BIM<Name>Properties attributes, is_<name> predicates, "
+        f"and the uppercase constant — a duplicate silently shadows the first entry."
+    )
+del _edit_type_names
+
+# Bind every registered ParametricObject as an uppercase class attribute so
+# call sites can reference ``tool.Parametric.ROOF`` directly. Renaming a
+# registry entry renames the constant; a typo at the call site surfaces as
+# AttributeError at module load.
+for _entry in Parametric.EDIT_TYPES:
+    setattr(Parametric, _entry.name.upper(), _entry)
+del _entry

src/bonsai/bonsai/tool/pset.py

@@ -18,10 +18,12 @@
 
 from __future__ import annotations
 
+import json
 from typing import TYPE_CHECKING, Any, Literal, Union, assert_never
 
 import bpy
 import ifcopenshell
+import ifcopenshell.api.pset
 import ifcopenshell.util.attribute
 import ifcopenshell.util.element
 
@@ -74,6 +76,34 @@ class Pset(bonsai.core.tool.Pset):
         if pset:
             return tool.Ifc.get().by_id(pset["id"])
 
+    @classmethod
+    def upsert_pset(
+        cls,
+        element: ifcopenshell.entity_instance,
+        pset_name: str,
+        properties: dict[str, Any],
+    ) -> ifcopenshell.entity_instance:
+        """Get or create ``pset_name`` on ``element``, write ``properties``, return the pset.
+        Centralises the get-element-pset → add-pset-if-missing → edit-pset idiom."""
+        ifc_file = tool.Ifc.get()
+        pset = cls.get_element_pset(element, pset_name)
+        if not pset:
+            pset = ifcopenshell.api.pset.add_pset(ifc_file, product=element, name=pset_name)
+        ifcopenshell.api.pset.edit_pset(ifc_file, pset=pset, properties=properties)
+        return pset
+
+    @classmethod
+    def write_bbim_data(
+        cls,
+        element: ifcopenshell.entity_instance,
+        pset_name: str,
+        data: dict[str, Any],
+    ) -> ifcopenshell.entity_instance:
+        """Get or create the BBIM_<Type> pset and write ``data`` as the IfcText-serialised
+        JSON ``Data`` property. Canonical writer for parametric-modifier pset state."""
+        data_text = tool.Ifc.get().createIfcText(json.dumps(data, default=list))
+        return cls.upsert_pset(element, pset_name, {"Data": data_text})
+
     @classmethod
     def get_pset_props(cls, obj: str, obj_type: tool.Ifc.OBJECT_TYPE) -> PsetProperties:
         if obj_type == "Object":