diff --git a/src/bonsai/bonsai/bim/module/debug/operator.py b/src/bonsai/bonsai/bim/module/debug/operator.py
index 966d7006fe..7e89eda418 100644
--- a/src/bonsai/bonsai/bim/module/debug/operator.py
+++ b/src/bonsai/bonsai/bim/module/debug/operator.py
@@ -183,6 +183,9 @@ class ValidateIfcAssets(bpy.types.Operator):
 
         ifc_classes = {
             "IfcMaterial": "Name",
+            "IfcMaterialLayerSet": "LayerSetName",
+            "IfcMaterialConstituentSet": "Name",
+            "IfcMaterialProfileSet": "Name",
             "IfcProfileDef": "ProfileName",
             "IfcPresentationStyle": "Name",
         }
diff --git a/src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py b/src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py
index 00c11dc72c..f074129b1f 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py
@@ -40,6 +40,7 @@ APPENDABLE_ASSET = Literal[
     "IfcPresentationStyle",
 ]
 APPENDABLE_ASSET_TYPES = get_args(APPENDABLE_ASSET)
+MATERIAL_SETS = ("IfcMaterialLayerSet", "IfcMaterialConstituentSet", "IfcMaterialProfileSet")
 
 
 def append_asset(
@@ -261,6 +262,15 @@ class Usecase:
         elif element.is_a("IfcMaterial"):
             name = element.Name
             return next((e for e in self.file.by_type("IfcMaterial") if e.Name == name), None)
+
+        elif element in MATERIAL_SETS:
+            ifc_class = element.is_a()
+            name_attr = "LayerSetName" if ifc_class == "IfcMaterialLayerSet" else "Name"
+            material_set_name = getattr(element, name_attr)
+            if material_set_name is None:
+                return
+            return next((e for e in self.file.by_type(ifc_class) if getattr(e, name_attr) == material_set_name), None)
+
         elif element.is_a("IfcProfileDef"):
             profile_name = element.ProfileName
             if profile_name is None:
@@ -644,6 +654,17 @@ class Usecase:
                 reuse_identities[element_identity] = existing_material
                 return existing_material
 
+        elif ifc_class in MATERIAL_SETS:
+            name_attr = "LayerSetName" if ifc_class == "IfcMaterialLayerSet" else "Name"
+            material_set_name = getattr(element, name_attr)
+            if material_set_name is not None:
+                existing_material_set = next(
+                    (e for e in ifc_file.by_type(ifc_class) if getattr(e, name_attr) == material_set_name), None
+                )
+                if existing_material_set is not None:
+                    reuse_identities[element_identity] = existing_material_set
+                    return existing_material_set
+
         elif element.is_a("IfcPresentationStyle"):
             style_name = element.Name
             if style_name is not None:
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 5fc6127c21..f0f4abe53e 100644
--- a/src/ifcopenshell-python/test/api/project/test_append_asset.py
+++ b/src/ifcopenshell-python/test/api/project/test_append_asset.py
@@ -774,3 +774,47 @@ class TestAppendAssetIFC4(test.bootstrap.IFC4, TestAppendAssetIFC2X3):
         assert len(materials) == 2 and all(m.Name == "TestMaterial" for m in materials)
         styles = self.file.by_type("IfcSurfaceStyle")
         assert len(styles) == 2 and all(s.Name == "TestStyle" for s in styles)
+
+    def test_not_duplicate_material_sets_based_on_name(self):
+        # Setup library.
+        library = ifcopenshell.api.project.create_file(version=self.file.schema)
+        ifcopenshell.api.root.create_entity(library, ifc_class="IfcProject")
+        model = ifcopenshell.api.context.add_context(library, context_type="Model")
+        body = ifcopenshell.api.context.add_context(
+            library, context_type="Model", context_identifier="Body", target_view="MODEL_VIEW", parent=model
+        )
+        column_type = ifcopenshell.api.root.create_entity(library, "IfcColumnType")
+        material_set = ifcopenshell.api.material.add_material_set(
+            library, set_type="IfcMaterialProfileSet", name="TestProfileSet"
+        )
+        ifcopenshell.api.material.assign_material(
+            library, [column_type], material=material_set, type="IfcMaterialProfileSet"
+        )
+
+        ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcProject")
+        # Test adding a profile with existing name.
+        ifcopenshell.api.material.add_material_set(self.file, set_type="IfcMaterialProfileSet", name="TestProfileSet")
+        ifcopenshell.api.project.append_asset(self.file, library, column_type)
+        assert len(self.file.by_type("IfcMaterialProfileSet")) == 1
+
+    def test_duplicate_material_sets_if_uniqueness_is_not_assumed(self):
+        # Setup library.
+        library = ifcopenshell.api.project.create_file(version=self.file.schema)
+        ifcopenshell.api.root.create_entity(library, ifc_class="IfcProject")
+        model = ifcopenshell.api.context.add_context(library, context_type="Model")
+        body = ifcopenshell.api.context.add_context(
+            library, context_type="Model", context_identifier="Body", target_view="MODEL_VIEW", parent=model
+        )
+        column_type = ifcopenshell.api.root.create_entity(library, "IfcColumnType")
+        material_set = ifcopenshell.api.material.add_material_set(
+            library, set_type="IfcMaterialProfileSet", name="TestProfileSet"
+        )
+        ifcopenshell.api.material.assign_material(
+            library, [column_type], material=material_set, type="IfcMaterialProfileSet"
+        )
+
+        ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcProject")
+        # Test adding a profile with existing name.
+        ifcopenshell.api.material.add_material_set(self.file, set_type="IfcMaterialProfileSet", name="TestProfileSet")
+        ifcopenshell.api.project.append_asset(self.file, library, column_type, assume_asset_uniqueness_by_name=False)
+        assert len(self.file.by_type("IfcMaterialProfileSet")) == 2