diff --git a/src/bonsai/bonsai/bim/__init__.py b/src/bonsai/bonsai/bim/__init__.py
index fab7646162..e79dae87e8 100644
--- a/src/bonsai/bonsai/bim/__init__.py
+++ b/src/bonsai/bonsai/bim/__init__.py
@@ -271,6 +271,7 @@ def register():
     parametric_lifecycle.install_parametric_lifecycle_handlers()
     bpy.app.handlers.load_post.append(handler.load_post)
     bpy.app.handlers.load_post.append(handler.loadIfcStore)
+    bpy.app.handlers.save_post.append(handler.save_post)
     bpy.types.Scene.BIMProperties = bpy.props.PointerProperty(type=prop.BIMProperties)
     bpy.types.Scene.BIMSnapProperties = bpy.props.PointerProperty(type=prop.BIMSnapProperties)
     bpy.types.Scene.BIMSnapGroups = bpy.props.PointerProperty(type=prop.BIMSnapGroups)
@@ -329,6 +330,7 @@ def unregister():
     parametric_lifecycle.uninstall_parametric_lifecycle_handlers()
     bpy.app.handlers.load_post.remove(handler.load_post)
     bpy.app.handlers.load_post.remove(handler.loadIfcStore)
+    bpy.app.handlers.save_post.remove(handler.save_post)
     del bpy.types.Scene.BIMProperties
     del bpy.types.Collection.BIMCollectionProperties
     del bpy.types.Object.BIMObjectProperties
diff --git a/src/bonsai/bonsai/bim/handler.py b/src/bonsai/bonsai/bim/handler.py
index 58647d55bc..6c4506c574 100644
--- a/src/bonsai/bonsai/bim/handler.py
+++ b/src/bonsai/bonsai/bim/handler.py
@@ -432,6 +432,25 @@ def subscribe_to_viewport_shading_changes():
             )
 
 
+@persistent
+def save_post(scene) -> None:
+    """After saving the .blend file, convert the stored IFC path to relative if enabled."""
+    pprops = tool.Project.get_project_props()
+    if not pprops.use_relative_project_path:
+        return
+    bim_props = tool.Blender.get_bim_props()
+    ifc_path = bim_props.ifc_file
+    if not ifc_path or not os.path.isabs(ifc_path):
+        return
+    blend_dir = bpy.path.abspath("//")
+    if not blend_dir:
+        return
+    from bonsai.bim.ifc import IfcStore
+    rel_path = os.path.relpath(ifc_path, blend_dir)
+    bim_props.ifc_file = rel_path
+    IfcStore.set_path(ifc_path)  # keep IfcStore.path absolute for loading
+
+
 def _apply_save_file_invariants(scene: bpy.types.Scene) -> None:
     """Invariants enforced on every load_post: msgbus subscription, IFC owner
     settings, scene-bound caches, load-transient parametric state, and the
diff --git a/src/bonsai/bonsai/bim/module/project/operator.py b/src/bonsai/bonsai/bim/module/project/operator.py
index db6b6389ee..ca5943bb11 100644
--- a/src/bonsai/bonsai/bim/module/project/operator.py
+++ b/src/bonsai/bonsai/bim/module/project/operator.py
@@ -964,7 +964,7 @@ class LoadProject(bpy.types.Operator, IFCFileSelector, ImportHelper):
     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,
+        default=True,
     )
     should_start_fresh_session: bpy.props.BoolProperty(
         name="Should Start Fresh Session",
@@ -1875,7 +1875,7 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
     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)
+    use_relative_path: bpy.props.BoolProperty(name="Use Relative Path", default=True)
 
     if TYPE_CHECKING:
         filter_glob: str
diff --git a/src/bonsai/bonsai/bim/module/project/prop.py b/src/bonsai/bonsai/bim/module/project/prop.py
index 1408d2f786..a76ece1f5e 100644
--- a/src/bonsai/bonsai/bim/module/project/prop.py
+++ b/src/bonsai/bonsai/bim/module/project/prop.py
@@ -444,7 +444,7 @@ class BIMProjectProperties(PropertyGroup):
         items=get_parent_libaries,
     )
 
-    use_relative_project_path: BoolProperty(name="Use Relative Project Path", default=False)
+    use_relative_project_path: BoolProperty(name="Use Relative Project Path", default=True)
     should_save_metadata_for_this_file: BoolProperty(
         name="Save Session Data for This File",
         description="Enable saving session data (window layout, settings) to a metadata blend file for this specific IFC file",
diff --git a/src/bonsai/bonsai/bim/operator.py b/src/bonsai/bonsai/bim/operator.py
index f1ab24c7b0..3914bcace4 100644
--- a/src/bonsai/bonsai/bim/operator.py
+++ b/src/bonsai/bonsai/bim/operator.py
@@ -219,7 +219,7 @@ class SelectIfcFile(bpy.types.Operator, IFCFileSelector, ImportHelper):
     bl_options = {"REGISTER", "UNDO"}
     bl_description = f"Select a different IFC file.\n{tool.Blender.operator_invoke_filepath_hotkeys_description}"
     filter_glob: bpy.props.StringProperty(default="*.ifc;*.ifczip;*.ifcxml", options={"HIDDEN"})
-    use_relative_path: bpy.props.BoolProperty(name="Use Relative Path", default=False)
+    use_relative_path: bpy.props.BoolProperty(name="Use Relative Path", default=True)
     filename_ext = ".ifc"
 
     def execute(self, context):