diff --git a/src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py b/src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py
index e3d7a6aaea..b550ea30b8 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py
@@ -471,14 +471,6 @@ class Usecase:
         The problem with `file.add` it's recursively adding element and all it's attributes
         and there is no control to prevent it from adding certain type of elements.
         """
-        ifc_file = self.file
-        if not self.assume_asset_uniqueness_by_name:
-            return ifc_file.add(element)
-
-        reuse_identities = self.reuse_identities
-        element_identity = element.wrapped_data.identity()
-        if added_element := reuse_identities.get(element_identity):
-            return added_element
 
         def get_conversion_factor() -> float:
             nonlocal conversion_factor
@@ -489,6 +481,18 @@ class Usecase:
             conversion_factor = library_scale / current_scale
             return conversion_factor
 
+        ifc_file = self.file
+        if not self.assume_asset_uniqueness_by_name or element.id() == 0:
+            # file.add doesn't convert units for IfcLengthMeasure entities.
+            if element.is_a("IfcLengthMeasure"):
+                return ifc_file.create_entity(element.is_a(), element.wrappedValue * get_conversion_factor())
+            return ifc_file.add(element)
+
+        reuse_identities = self.reuse_identities
+        element_identity = element.wrapped_data.identity()
+        if added_element := reuse_identities.get(element_identity):
+            return added_element
+
         attributes_ = None
 
         def get_attributes() -> tuple[W.attribute, ...]:
@@ -541,7 +545,7 @@ class Usecase:
                 continue
 
             elif isinstance(attr_value, ifcopenshell.entity_instance):
-                attr_value = self.file_add(attr_value)
+                attr_value = file_add_(attr_value)
 
             elif isinstance(attr_value, tuple):
                 # Assume type is consistent across the tuple.
diff --git a/src/ifcopenshell-python/test/api/project/test_append_asset.py b/src/ifcopenshell-python/test/api/project/test_append_asset.py
index 68dc7b92f5..30f4322199 100644
--- a/src/ifcopenshell-python/test/api/project/test_append_asset.py
+++ b/src/ifcopenshell-python/test/api/project/test_append_asset.py
@@ -498,6 +498,17 @@ class TestAppendAssetIFC2X3(test.bootstrap.IFC2X3):
         updated_points = np.array(arbitrary_profile.OuterCurve.Points) * 0.001
         assert np.allclose(updated_points, new_arbitrary_profile.OuterCurve.Points)
 
+        # Entities without ids.
+        annotation = ifcopenshell.api.root.create_entity(library, "IfcAnnotation")
+        annotation.ObjectType = "LineOfSight"
+        pset = ifcopenshell.api.pset.add_pset(library, annotation, "Pset_AnnotationLineOfSight")
+        ifcopenshell.api.pset.edit_pset(library, pset, properties={"RoadVisibleDistanceLeft": 10})
+        new_annotation = ifcopenshell.api.project.append_asset(ifc_file, library, annotation)
+        assert (
+            ifcopenshell.util.element.get_pset(new_annotation, "Pset_AnnotationLineOfSight", "RoadVisibleDistanceLeft")
+            == 0.01
+        )
+
 
 class TestAppendAssetIFC4(test.bootstrap.IFC4, TestAppendAssetIFC2X3):
     # NOTE: breaks in IFC2X3 since IfcProfileDef doesn't have "HasProperties" inverse in ifc2x3