You can now count elements, tasks, and resources parametrically for cost items

src/ifcopenshell-python/ifcopenshell/api/cost/add_cost_item_quantity.py

@@ -14,8 +14,10 @@ class Usecase:
         # This is a bold assumption
         # https://forums.buildingsmart.org/t/how-does-a-cost-item-know-that-it-is-counting-a-controlled-product/3564
         if self.settings["ifc_class"] == "IfcQuantityCount" and self.settings["cost_item"].Controls:
+            count = 0
             for rel in self.settings["cost_item"].Controls:
-                quantity[3] += len(rel.RelatedObjects)
+                count += len(rel.RelatedObjects)
+            quantity[3] = count
         quantities = list(self.settings["cost_item"].CostQuantities or [])
         quantities.append(quantity)
         self.settings["cost_item"].CostQuantities = quantities