diff --git a/src/ifcblenderexport/blenderbim/bim/__init__.py b/src/ifcblenderexport/blenderbim/bim/__init__.py
index ede7d1d841..86c83ad22a 100644
--- a/src/ifcblenderexport/blenderbim/bim/__init__.py
+++ b/src/ifcblenderexport/blenderbim/bim/__init__.py
@@ -221,6 +221,9 @@ if bpy is not None:
         operator.RefreshDrawingList,
         operator.GetRepresentationIfcParameters,
         operator.UpdateIfcRepresentation,
+        operator.SetBlenderClashSetA,
+        operator.SetBlenderClashSetB,
+        operator.ExecuteBlenderClash,
         prop.StrProperty,
         prop.Attribute,
         prop.MaterialLayer,
diff --git a/src/ifcblenderexport/blenderbim/bim/operator.py b/src/ifcblenderexport/blenderbim/bim/operator.py
index dce8c7e224..0eaa53b7cb 100644
--- a/src/ifcblenderexport/blenderbim/bim/operator.py
+++ b/src/ifcblenderexport/blenderbim/bim/operator.py
@@ -4551,3 +4551,83 @@ class UpdateIfcRepresentation(bpy.types.Operator):
         ifc_importer.material_creator.mesh = mesh
         if ifc_importer.material_creator.parse_representation(element):
             ifc_importer.material_creator.assign_material_slots_to_faces(bpy.context.active_object)
+
+
+class BlenderClasher():
+    def process_clash_set(self):
+        import collision
+        a_cm = collision.CollisionManager()
+        b_cm = collision.CollisionManager()
+        self.add_to_cm(a_cm, bpy.context.scene.BIMProperties.blender_clash_set_a)
+        self.add_to_cm(b_cm, bpy.context.scene.BIMProperties.blender_clash_set_b)
+        results = a_cm.in_collision_other(b_cm, return_data=True)
+        if not results[0]:
+            print("No clashes")
+            return
+        for contact in results[1]:
+            if contact.raw.penetration_depth < 0.01:
+                continue
+            print("-----")
+            print(contact.names)
+            print(contact.raw.normal)
+            print(contact.raw.pos)
+
+    def add_to_cm(self, cm, object_names):
+        import numpy as np
+        import ifcclash
+        for object_name in object_names:
+            name = object_name.name
+            obj = bpy.data.objects[name]
+            triangulated_mesh = self.triangulate_mesh(obj)
+            mat = np.array(obj.matrix_world)
+            mesh = ifcclash.Mesh()
+            mesh.vertices = np.array([tuple(v.co) for v in triangulated_mesh.vertices])
+            mesh.faces = np.array([tuple(p.vertices) for p in triangulated_mesh.polygons])
+            cm.add_object(name, mesh, mat)
+
+    def triangulate_mesh(self, obj):
+        import bmesh
+        mesh = obj.evaluated_get(bpy.context.evaluated_depsgraph_get()).to_mesh()
+        bm = bmesh.new()
+        bm.from_mesh(mesh)
+        bmesh.ops.triangulate(bm, faces=bm.faces)
+        bm.to_mesh(mesh)
+        bm.free()
+        del bm
+        return mesh
+
+
+class SetBlenderClashSetA(bpy.types.Operator):
+    bl_idname = "bim.set_blender_clash_set_a"
+    bl_label = "Set Blender Clash Set A"
+
+    def execute(self, context):
+        while len(bpy.context.scene.BIMProperties.blender_clash_set_a) > 0:
+            bpy.context.scene.BIMProperties.blender_clash_set_a.remove(0)
+        for obj in bpy.context.selected_objects:
+            new = bpy.context.scene.BIMProperties.blender_clash_set_a.add()
+            new.name = obj.name
+        return {"FINISHED"}
+
+
+class SetBlenderClashSetB(bpy.types.Operator):
+    bl_idname = "bim.set_blender_clash_set_b"
+    bl_label = "Set Blender Clash Set B"
+
+    def execute(self, context):
+        while len(bpy.context.scene.BIMProperties.blender_clash_set_b) > 0:
+            bpy.context.scene.BIMProperties.blender_clash_set_b.remove(0)
+        for obj in bpy.context.selected_objects:
+            new = bpy.context.scene.BIMProperties.blender_clash_set_b.add()
+            new.name = obj.name
+        return {"FINISHED"}
+
+
+class ExecuteBlenderClash(bpy.types.Operator):
+    bl_idname = "bim.execute_blender_clash"
+    bl_label = "Execute Blender Clash"
+
+    def execute(self, context):
+        blender_clasher = BlenderClasher()
+        blender_clasher.process_clash_set()
+        return {"FINISHED"}
diff --git a/src/ifcblenderexport/blenderbim/bim/prop.py b/src/ifcblenderexport/blenderbim/bim/prop.py
index 577c4b9870..d9b0371e16 100644
--- a/src/ifcblenderexport/blenderbim/bim/prop.py
+++ b/src/ifcblenderexport/blenderbim/bim/prop.py
@@ -1514,6 +1514,8 @@ class BIMProperties(PropertyGroup):
     active_document_information_index: IntProperty(name="Active Document Information Index")
     document_references: CollectionProperty(name="Document References", type=DocumentReference)
     active_document_reference_index: IntProperty(name="Active Document Reference Index")
+    blender_clash_set_a: CollectionProperty(name="Blender Clash Set A", type=StrProperty)
+    blender_clash_set_b: CollectionProperty(name="Blender Clash Set B", type=StrProperty)
     clash_sets: CollectionProperty(name="Clash Sets", type=ClashSet)
     active_clash_set_index: IntProperty(name="Active Clash Set Index")
     constraints: CollectionProperty(name="Constraints", type=Constraint)
diff --git a/src/ifcblenderexport/blenderbim/bim/ui.py b/src/ifcblenderexport/blenderbim/bim/ui.py
index 53462c1546..e2dc5830c2 100644
--- a/src/ifcblenderexport/blenderbim/bim/ui.py
+++ b/src/ifcblenderexport/blenderbim/bim/ui.py
@@ -2130,6 +2130,17 @@ class BIM_PT_ifcclash(Panel):
         scene = context.scene
         props = scene.BIMProperties
 
+        layout.label(text="Blender Clash:")
+
+        row = layout.row(align=True)
+        row.operator("bim.set_blender_clash_set_a")
+        row.operator("bim.set_blender_clash_set_b")
+
+        row = layout.row(align=True)
+        row.operator("bim.execute_blender_clash")
+
+        layout.label(text="IFC Clash:")
+
         row = layout.row(align=True)
         row.operator("bim.add_clash_set")
         row.operator("bim.import_clash_sets", text="", icon="IMPORT")