Fix create spaces from walls z-value (#3248)

Co-authored-by: Dion Moult <dion@thinkmoult.com>

src/blenderbim/blenderbim/bim/module/model/space.py

@@ -247,6 +247,9 @@ class GenerateSpacesFromWalls(bpy.types.Operator, tool.Ifc.Operator):
 
             self.set_obj_origin_to_bboxcenter(obj)
 
+            if z is not 0:
+                obj.location = obj.location + Vector((0,0,z))
+
             context.view_layer.active_layer_collection.collection.objects.link(obj)
             bpy.ops.bim.assign_class(obj=obj.name, ifc_class="IfcSpace")
             container_obj = tool.Ifc.get_object(container)