You can now import a cost schedule from an IFC project library

src/blenderbim/blenderbim/bim/module/project/operator.py

@@ -172,7 +172,7 @@ class RefreshLibrary(bpy.types.Operator):
         self.props.active_library_element = ""
 
         types = IfcStore.library_file.wrapped_data.types_with_super()
-        for importable_type in ["IfcTypeProduct", "IfcMaterial"]:
+        for importable_type in ["IfcTypeProduct", "IfcMaterial", "IfcCostSchedule"]:
             if importable_type in types:
                 new = self.props.library_elements.add()
                 new.name = importable_type

src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py

@@ -12,21 +12,33 @@ class Usecase:
     def execute(self):
         self.added_elements = set()
         if self.settings["element"].is_a("IfcTypeProduct"):
-            try:
-                self.file.by_guid(self.settings["element"].GlobalId)
-                return
-            except:
-                pass
             return self.append_type_product()
         elif self.settings["element"].is_a("IfcMaterial"):
-            if [e for e in self.file.by_type("IfcMaterial") if e.Name == self.settings["element"].Name]:
-                return
             return self.append_material()
+        elif self.settings["element"].is_a("IfcCostSchedule"):
+            return self.append_cost_schedule()
+
+    def is_already_appended(self):
+        try:
+            self.file.by_guid(self.settings["element"].GlobalId)
+            return True
+        except:
+            return False
 
     def append_material(self):
+        if [e for e in self.file.by_type("IfcMaterial") if e.Name == self.settings["element"].Name]:
+            return
         return self.file.add(self.settings["element"])
 
+    def append_cost_schedule(self):
+        if self.is_already_appended():
+            return
+        self.whitelisted_inverse_attributes = {"IfcCostSchedule": ["Controls"], "IfcCostItem": ["IsNestedBy"]}
+        return self.add_element(self.settings["element"])
+
     def append_type_product(self):
+        if self.is_already_appended():
+            return
         self.whitelisted_inverse_attributes = {
             "IfcObjectDefinition": ["HasAssociations"],
             "IfcMaterialDefinition": ["HasExternalReferences", "HasProperties"],