Optimise aggregate creation on large file imports

src/ifcblenderexport/blenderbim/bim/import_ifc.py

@@ -1189,16 +1189,26 @@ class IfcImporter:
 
         obj = bpy.data.objects.new("{}/{}".format(element.is_a(), element.Name), None)
         self.link_element(element, obj)
-        self.place_object_in_spatial_tree(element, obj)
+
+        container_collection = self.get_aggregate_collection(element)
 
         collection = bpy.data.collections.new(obj.name)
-        obj.users_collection[0].children.link(collection)
-        obj.users_collection[0].objects.unlink(obj)
+        container_collection.children.link(collection)
         collection.objects.link(obj)
 
         self.aggregates[element.GlobalId] = obj
         self.aggregate_collections[rel_aggregate.id()] = collection
 
+    def get_aggregate_collection(self, element):
+        if hasattr(element, "ContainedInStructure") and element.ContainedInStructure:
+            container = element.ContainedInStructure[0].RelatingStructure
+        elif hasattr(element, "Decomposes") and element.Decomposes:
+            container = element.Decomposes[0].RelatingObject
+
+        if container.is_a("IfcSpace"):
+            return self.get_aggregate_collection(container)
+        return self.spatial_structure_elements[container.GlobalId]["blender"]
+
     def create_openings_collection(self):
         self.opening_collection = bpy.data.collections.new("IfcOpeningElements")
         self.project["blender"].children.link(self.opening_collection)