diff --git a/src/blenderbim/Makefile b/src/blenderbim/Makefile
index f6ce39e6af..7277fa9446 100644
--- a/src/blenderbim/Makefile
+++ b/src/blenderbim/Makefile
@@ -21,6 +21,7 @@ BOOST_URL:=https://anaconda.org/conda-forge/boost/1.74.0/download/linux-64/boost
 endif
 ASSIMP_URL:=https://anaconda.org/conda-forge/assimp/5.0.1/download/linux-64/assimp-5.0.1-hedfc422_6.tar.bz2
 OCTOMAP_URL:=https://anaconda.org/conda-forge/octomap/1.9.7/download/linux-64/octomap-1.9.7-h4bd325d_0.tar.bz2
+ZLIB_URL:=https://anaconda.org/conda-forge/zlib/1.2.11/download/linux-64/zlib-1.2.11-h516909a_1010.tar.bz2
 endif
 
 ifeq ($(PLATFORM), macos)
@@ -36,6 +37,7 @@ BOOST_URL:=https://anaconda.org/conda-forge/boost/1.74.0/download/osx-64/boost-1
 endif
 ASSIMP_URL:=https://anaconda.org/conda-forge/assimp/5.0.1/download/osx-64/assimp-5.0.1-h1224e73_6.tar.bz2
 OCTOMAP_URL:=https://anaconda.org/conda-forge/octomap/1.9.7/download/osx-64/octomap-1.9.7-h940c156_0.tar.bz2
+ZLIB_URL:=https://anaconda.org/conda-forge/zlib/1.2.11/download/osx-64/zlib-1.2.11-h7795811_1010.tar.bz2
 endif
 
 ifeq ($(PLATFORM), win)
@@ -51,6 +53,7 @@ BOOST_URL:=https://anaconda.org/conda-forge/boost/1.74.0/download/win-64/boost-1
 endif
 ASSIMP_URL:=https://anaconda.org/conda-forge/assimp/5.0.1/download/win-64/assimp-5.0.1-hc2aa0de_6.tar.bz2
 OCTOMAP_URL:=https://anaconda.org/conda-forge/octomap/1.9.7/download/win-64/octomap-1.9.7-h5362a0b_0.tar.bz2
+ZLIB_URL:=https://anaconda.org/conda-forge/zlib/1.2.11/download/win-64/zlib-1.2.11-h62dcd97_1010.tar.bz2
 endif
 
 .PHONY: dist
@@ -229,15 +232,16 @@ endif
 	mkdir dist/working
 	cd dist/working && wget $(HPPFCL_URL)
 	cd dist/working && tar -xf hpp-fcl*
-	cp -r dist/working/lib/$(PYLIBDIR)/site-packages/hppfcl dist/blenderbim/libs/site/packages/
 ifeq ($(PLATFORM), linux)
+	cp -r dist/working/lib/$(PYLIBDIR)/site-packages/hppfcl dist/blenderbim/libs/site/packages/
 	cp -r dist/working/lib/*.so* dist/blenderbim/libs/
 endif
 ifeq ($(PLATFORM), macos)
+	cp -r dist/working/lib/$(PYLIBDIR)/site-packages/hppfcl dist/blenderbim/libs/site/packages/
 	cp -r dist/working/lib/*.dylib dist/blenderbim/libs/
 endif
 ifeq ($(PLATFORM), win)
-	cp -r dist/working/Library/lib/*.lib dist/blenderbim/libs/site/packages/hppfcl/
+	cp -r dist/working/Lib/site-packages/hppfcl dist/blenderbim/libs/site/packages/
 	cp -r dist/working/Library/bin/*.dll dist/blenderbim/libs/site/packages/hppfcl/
 endif
 	rm -rf dist/working
@@ -253,7 +257,6 @@ ifeq ($(PLATFORM), macos)
 	cp -r dist/working/lib/*.dylib dist/blenderbim/libs/
 endif
 ifeq ($(PLATFORM), win)
-	cp -r dist/working/Library/bin/*.lib dist/blenderbim/libs/site/packages/hppfcl/
 	cp -r dist/working/Library/bin/*.dll dist/blenderbim/libs/site/packages/hppfcl/
 endif
 	rm -rf dist/working
@@ -269,7 +272,6 @@ ifeq ($(PLATFORM), macos)
 	cp -r dist/working/lib/*.dylib dist/blenderbim/libs/
 endif
 ifeq ($(PLATFORM), win)
-	cp -r dist/working/Library/bin/*.lib dist/blenderbim/libs/site/packages/hppfcl/
 	cp -r dist/working/Library/bin/*.dll dist/blenderbim/libs/site/packages/hppfcl/
 endif
 	rm -rf dist/working
@@ -285,8 +287,7 @@ ifeq ($(PLATFORM), macos)
 	cp -r dist/working/lib/*.dylib dist/blenderbim/libs/
 endif
 ifeq ($(PLATFORM), win)
-	cp -r dist/working/Library/bin/*.lib dist/blenderbim/libs/site/packages/hppfcl/
-	cp -r dist/working/Library/bin/*.dll dist/blenderbim/libs/site/packages/hppfcl/
+	# Uh, do nothing, apparently? No DLLs are shipped.
 endif
 	rm -rf dist/working
 
@@ -301,7 +302,21 @@ ifeq ($(PLATFORM), macos)
 	cp -r dist/working/lib/*.dylib dist/blenderbim/libs/
 endif
 ifeq ($(PLATFORM), win)
-	cp -r dist/working/Library/bin/*.lib dist/blenderbim/libs/site/packages/hppfcl/
+	cp -r dist/working/Library/bin/*.dll dist/blenderbim/libs/site/packages/hppfcl/
+endif
+	rm -rf dist/working
+
+	# Required by hpp-fcl
+	mkdir dist/working
+	cd dist/working && wget $(ZLIB_URL)
+	cd dist/working && tar -xf zlib*
+ifeq ($(PLATFORM), linux)
+	cp -r dist/working/lib/*.so* dist/blenderbim/libs/
+endif
+ifeq ($(PLATFORM), macos)
+	cp -r dist/working/lib/*.dylib dist/blenderbim/libs/
+endif
+ifeq ($(PLATFORM), win)
 	cp -r dist/working/Library/bin/*.dll dist/blenderbim/libs/site/packages/hppfcl/
 endif
 	rm -rf dist/working
diff --git a/src/blenderbim/blenderbim/bim/module/root/operator.py b/src/blenderbim/blenderbim/bim/module/root/operator.py
index f67b472151..d0a5910a84 100644
--- a/src/blenderbim/blenderbim/bim/module/root/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/root/operator.py
@@ -287,7 +287,7 @@ class CopyClass(bpy.types.Operator):
                 bpy.ops.bim.assign_type(relating_type=relating_type.id(), related_object=obj.name)
             else:
                 bpy.ops.bim.add_representation(obj=obj.name)
-            if result.is_a("IfcSpatialElement") or element.is_a("IfcSpatialStructureElement"):
+            if result.is_a("IfcSpatialElement") or result.is_a("IfcSpatialStructureElement"):
                 self.place_in_spatial_collection(old_element, obj)
         return {"FINISHED"}
 
diff --git a/src/blenderbim/blenderbim/libs/site/packages/hppfcl.pth b/src/blenderbim/blenderbim/libs/site/packages/hppfcl.pth
new file mode 100644
index 0000000000..c0d165217a
--- /dev/null
+++ b/src/blenderbim/blenderbim/libs/site/packages/hppfcl.pth
@@ -0,0 +1,3 @@
+# expose hppfcl as site-package
+
+hppfcl
diff --git a/src/ifcclash/ifcclash/collider.py b/src/ifcclash/ifcclash/collider.py
index a2fd0314d4..b04dc3a9f7 100644
--- a/src/ifcclash/ifcclash/collider.py
+++ b/src/ifcclash/ifcclash/collider.py
@@ -82,7 +82,7 @@ class Collider:
         mesh_faces = [(int(f[i]), int(f[i + 1]), int(f[i + 2])) for i in range(0, len(f), 3)]
 
         bvh = hppfcl.BVHModelOBB()
-        bvh.beginModel(num_tris=len(mesh.faces), num_vertices=len(mesh_verts))
+        bvh.beginModel(len(mesh_faces), len(mesh_verts))
         vertices = hppfcl.StdVec_Vec3f()
         [vertices.append(v) for v in mesh_verts]
         triangles = hppfcl.StdVec_Triangle()
diff --git a/src/ifcclash/ifcclash/ifcclash.py b/src/ifcclash/ifcclash/ifcclash.py
index c966311213..89baee1b5b 100644
--- a/src/ifcclash/ifcclash/ifcclash.py
+++ b/src/ifcclash/ifcclash/ifcclash.py
@@ -155,14 +155,14 @@ class Clasher:
         return np.linalg.inv(look_at_transform)
 
     def export_json(self):
-        results = self.clash_sets.copy()
-        for result in results:
-            for ab in ["a", "b"]:
-                for data in result[ab]:
-                    if "ifc" in data:
-                        del data["ifc"]
+        clash_sets = self.clash_sets.copy()
+        for clash_set in clash_sets:
+            for source in clash_set["a"]:
+                del source["ifc"]
+            for source in clash_set.get("b", []):
+                del source["ifc"]
         with open(self.settings.output, "w", encoding="utf-8") as clashes_file:
-            json.dump(results, clashes_file, indent=4)
+            json.dump(clash_sets, clashes_file, indent=4)
 
     def get_element(self, clash_set, global_id):
         for source in clash_set: