diff --git a/src/ifcblenderexport/blenderbim/bim/export_ifc.py b/src/ifcblenderexport/blenderbim/bim/export_ifc.py
index 3e8f1edf23..f43d4cfef6 100644
--- a/src/ifcblenderexport/blenderbim/bim/export_ifc.py
+++ b/src/ifcblenderexport/blenderbim/bim/export_ifc.py
@@ -6,12 +6,13 @@ import datetime
 import os
 import zipfile
 import tempfile
+import ifcopenshell
+import ifcopenshell.util.pset
 from pathlib import Path
 from mathutils import Vector, Matrix
 from .helper import SIUnitHelper, get_representation_elements
 from . import schema
 from . import ifc
-import ifcopenshell
 import addon_utils
 
 
@@ -466,10 +467,10 @@ class IfcParser:
             return
         qto_names = self.get_applicable_qtos(ifc_class)
         for name in qto_names:
-            if name not in schema.ifc.qtos:
+            if name not in ifcopenshell.util.pset.qtos:
                 continue
             has_automatic_value = False
-            props = schema.ifc.qtos[name]["HasPropertyTemplates"].keys()
+            props = ifcopenshell.util.pset.qtos[name]["HasPropertyTemplates"].keys()
             guessed_values = {}
             for prop_name in props:
                 value = self.qto_calculator.guess_quantity(prop_name, props, obj)
@@ -1666,12 +1667,12 @@ class IfcExporter:
                 )
 
     def create_qto_properties(self, qto):
-        if qto["attributes"]["Name"] in schema.ifc.qtos:
+        if qto["attributes"]["Name"] in ifcopenshell.util.pset.qtos:
             return self.create_templated_qto_properties(qto)
         return self.create_custom_qto_properties(qto)
 
     def create_pset_properties(self, pset):
-        if pset["attributes"]["Name"] in schema.ifc.psets:
+        if pset["attributes"]["Name"] in ifcopenshell.util.pset.psets:
             return self.create_templated_pset_properties(pset)
         return self.create_custom_pset_properties(pset)
 
@@ -1704,7 +1705,7 @@ class IfcExporter:
 
     def create_templated_pset_properties(self, pset):
         properties = []
-        templates = schema.ifc.psets[pset["attributes"]["Name"]]["HasPropertyTemplates"]
+        templates = ifcopenshell.util.pset.psets[pset["attributes"]["Name"]]["HasPropertyTemplates"]
         for name, data in templates.items():
             if name not in pset["raw"]:
                 continue
@@ -1731,7 +1732,7 @@ class IfcExporter:
 
     def create_templated_qto_properties(self, qto):
         properties = []
-        templates = schema.ifc.qtos[qto["attributes"]["Name"]]["HasPropertyTemplates"]
+        templates = ifcopenshell.util.pset.qtos[qto["attributes"]["Name"]]["HasPropertyTemplates"]
         for name, data in templates.items():
             if name not in qto["raw"]:
                 continue
@@ -3157,10 +3158,7 @@ class IfcExporter:
             )
 
     def relate_spaces_to_boundary_elements(self):
-        for (
-            relating_space_index,
-            relationships,
-        ) in self.ifc_parser.rel_space_boundaries.items():
+        for (relating_space_index, relationships,) in self.ifc_parser.rel_space_boundaries.items():
             for relationship in relationships:
                 relationship["attributes"]["GlobalId"] = ifcopenshell.guid.new()
                 relationship["attributes"]["RelatedBuildingElement"] = self.ifc_parser.products[
diff --git a/src/ifcblenderexport/blenderbim/bim/import_ifc.py b/src/ifcblenderexport/blenderbim/bim/import_ifc.py
index 4056ac18f3..0fe458f506 100644
--- a/src/ifcblenderexport/blenderbim/bim/import_ifc.py
+++ b/src/ifcblenderexport/blenderbim/bim/import_ifc.py
@@ -3,6 +3,7 @@ import ifcopenshell.geom
 import ifcopenshell.util.geolocation
 import ifcopenshell.util.selector
 import ifcopenshell.util.element
+import ifcopenshell.util.pset
 import bpy
 import bmesh
 import os
@@ -206,8 +207,8 @@ class MaterialCreator:
     def add_pset(self, pset, obj):
         new_pset = obj.BIMMaterialProperties.psets.add()
         new_pset.name = pset.Name
-        if new_pset.name in schema.ifc.psets:
-            for prop_name in schema.ifc.psets[new_pset.name]["HasPropertyTemplates"].keys():
+        if new_pset.name in ifcopenshell.util.pset.psets:
+            for prop_name in ifcopenshell.util.pset.psets[new_pset.name]["HasPropertyTemplates"].keys():
                 prop = new_pset.properties.add()
                 prop.name = prop_name
         for prop in pset.Properties:
@@ -1338,8 +1339,8 @@ class IfcImporter:
     def add_pset(self, pset, obj):
         new_pset = obj.BIMObjectProperties.psets.add()
         new_pset.name = pset.Name
-        if new_pset.name in schema.ifc.psets:
-            for prop_name in schema.ifc.psets[new_pset.name]["HasPropertyTemplates"].keys():
+        if new_pset.name in ifcopenshell.util.pset.psets:
+            for prop_name in ifcopenshell.util.pset.psets[new_pset.name]["HasPropertyTemplates"].keys():
                 prop = new_pset.properties.add()
                 prop.name = prop_name
         # Invalid IFC, but some vendors like Solidworks do this so we accomodate it
@@ -1358,8 +1359,8 @@ class IfcImporter:
     def add_qto(self, qto, obj):
         new_qto = obj.BIMObjectProperties.qtos.add()
         new_qto.name = str(qto.Name)
-        if new_qto.name in schema.ifc.qtos:
-            for prop_name in schema.ifc.qtos[new_qto.name]["HasPropertyTemplates"].keys():
+        if new_qto.name in ifcopenshell.util.pset.qtos:
+            for prop_name in ifcopenshell.util.pset.qtos[new_qto.name]["HasPropertyTemplates"].keys():
                 prop = new_qto.properties.add()
                 prop.name = prop_name
         for prop in qto.Quantities:
diff --git a/src/ifcblenderexport/blenderbim/bim/operator.py b/src/ifcblenderexport/blenderbim/bim/operator.py
index ffb73219e1..4ddd4229dc 100644
--- a/src/ifcblenderexport/blenderbim/bim/operator.py
+++ b/src/ifcblenderexport/blenderbim/bim/operator.py
@@ -9,6 +9,7 @@ import subprocess
 import ifcopenshell
 import ifcopenshell.util.selector
 import ifcopenshell.util.geolocation
+import ifcopenshell.util.pset
 import tempfile
 from . import export_ifc
 from . import import_ifc
@@ -836,11 +837,11 @@ class AddQto(bpy.types.Operator):
 
     def execute(self, context):
         name = bpy.context.active_object.BIMObjectProperties.qto_name
-        if name not in schema.ifc.qtos:
+        if name not in ifcopenshell.util.pset.qtos:
             return {"FINISHED"}
         qto = bpy.context.active_object.BIMObjectProperties.qtos.add()
         qto.name = name
-        for prop_name in schema.ifc.qtos[name]["HasPropertyTemplates"].keys():
+        for prop_name in ifcopenshell.util.pset.qtos[name]["HasPropertyTemplates"].keys():
             prop = qto.properties.add()
             prop.name = prop_name
         return {"FINISHED"}
@@ -852,11 +853,11 @@ class AddPset(bpy.types.Operator):
 
     def execute(self, context):
         pset_name = bpy.context.active_object.BIMObjectProperties.pset_name
-        if pset_name not in schema.ifc.psets:
+        if pset_name not in ifcopenshell.util.pset.psets:
             return {"FINISHED"}
         pset = bpy.context.active_object.BIMObjectProperties.psets.add()
         pset.name = pset_name
-        for prop_name in schema.ifc.psets[pset_name]["HasPropertyTemplates"].keys():
+        for prop_name in ifcopenshell.util.pset.psets[pset_name]["HasPropertyTemplates"].keys():
             prop = pset.properties.add()
             prop.name = prop_name
         return {"FINISHED"}
@@ -2729,7 +2730,6 @@ class CopyPropertyToSelection(bpy.types.Operator):
 
     def execute(self, context):
         self.applicable_psets_cache = {}
-        self.empty = ifcopenshell.file()
         for obj in bpy.context.selected_objects:
             if "/" not in obj.name:
                 continue
@@ -2740,7 +2740,7 @@ class CopyPropertyToSelection(bpy.types.Operator):
                     continue
                 pset = obj.BIMObjectProperties.psets.add()
                 pset.name = self.pset_name
-                for template_prop_name in schema.ifc.psets[self.pset_name]["HasPropertyTemplates"].keys():
+                for template_prop_name in ifcopenshell.util.pset.psets[self.pset_name]["HasPropertyTemplates"].keys():
                     prop = pset.properties.add()
                     prop.name = template_prop_name
             prop = pset.properties.get(self.prop_name)
@@ -2748,15 +2748,11 @@ class CopyPropertyToSelection(bpy.types.Operator):
                 prop.string_value = self.prop_value
         return {"FINISHED"}
 
-    # TODO: move into util module. See bug #971
     def get_applicable_psets(self, element_class):
         if element_class not in self.applicable_psets_cache:
-            element = self.empty.create_entity(element_class)
-            applicable_psets = []
-            for ifc_class, pset_names in schema.ifc.applicable_psets.items():
-                if element.is_a(ifc_class):
-                    applicable_psets.extend(pset_names)
-            self.applicable_psets_cache[element_class] = applicable_psets
+            self.applicable_psets_cache[element_class] = ifcopenshell.util.pset.get_applicable_psetqtos(
+                bpy.context.scene.BIMProperties.export_schema, element_class, is_pset=True
+            )
         return self.applicable_psets_cache[element_class]
 
 
@@ -3604,11 +3600,11 @@ class GuessQuantity(bpy.types.Operator):
         prop.string_value = str(round(quantity, 3))
 
     def add_qto(self, obj, name):
-        if name not in schema.ifc.qtos:
+        if name not in ifcopenshell.util.pset.qtos:
             return
         qto = obj.BIMObjectProperties.qtos.add()
         qto.name = name
-        for prop_name in schema.ifc.qtos[name]["HasPropertyTemplates"].keys():
+        for prop_name in ifcopenshell.util.pset.qtos[name]["HasPropertyTemplates"].keys():
             prop = qto.properties.add()
             prop.name = prop_name
         return qto
diff --git a/src/ifcblenderexport/blenderbim/bim/prop.py b/src/ifcblenderexport/blenderbim/bim/prop.py
index bdd76e8ff2..99d12d58d5 100644
--- a/src/ifcblenderexport/blenderbim/bim/prop.py
+++ b/src/ifcblenderexport/blenderbim/bim/prop.py
@@ -2,6 +2,7 @@ import json
 import os
 import csv
 import ifcopenshell
+import ifcopenshell.util.pset
 from pathlib import Path
 from . import export_ifc
 from . import schema
@@ -429,29 +430,25 @@ def refreshReferences(self, context):
     context.scene.BIMProperties.classification_references.root = ""
 
 
-# TODO: move into util module. See bug #971
 def getPsetNames(self, context):
     global psetnames_enum
     psetnames_enum.clear()
     if "/" in context.active_object.name and context.active_object.name.split("/")[0] in schema.ifc.elements:
-        empty = ifcopenshell.file()
-        element = empty.create_entity(context.active_object.name.split("/")[0])
-        for ifc_class, pset_names in schema.ifc.applicable_psets.items():
-            if element.is_a(ifc_class):
-                psetnames_enum.extend([(p, p, "") for p in pset_names])
+        pset_names = ifcopenshell.util.pset.get_applicable_psetqtos(
+            bpy.context.scene.BIMProperties.export_schema, context.active_object.name.split("/")[0], is_pset=True
+        )
+        psetnames_enum.extend([(p, p, "") for p in pset_names])
     return psetnames_enum
 
 
-# TODO: move into util module. See bug #971
 def getQtoNames(self, context):
     global qtonames_enum
     qtonames_enum.clear()
     if "/" in context.active_object.name and context.active_object.name.split("/")[0] in schema.ifc.elements:
-        empty = ifcopenshell.file()
-        element = empty.create_entity(context.active_object.name.split("/")[0])
-        for ifc_class, qto_names in schema.ifc.applicable_qtos.items():
-            if element.is_a(ifc_class):
-                qtonames_enum.extend([(q, q, "") for q in qto_names])
+        qto_names = ifcopenshell.util.pset.get_applicable_psetqtos(
+            bpy.context.scene.BIMProperties.export_schema, context.active_object.name.split("/")[0], is_qto=True
+        )
+        qtonames_enum.extend([(q, q, "") for q in qto_names])
     return qtonames_enum
 
 
diff --git a/src/ifcblenderexport/blenderbim/bim/schema.py b/src/ifcblenderexport/blenderbim/bim/schema.py
index 4a34a042d3..958567ac09 100644
--- a/src/ifcblenderexport/blenderbim/bim/schema.py
+++ b/src/ifcblenderexport/blenderbim/bim/schema.py
@@ -1,6 +1,7 @@
 import os
 import json
 import ifcopenshell
+import ifcopenshell.util.pset
 import bpy
 from pathlib import Path
 
@@ -30,14 +31,10 @@ class IfcSchema:
         self.property_files = []
         property_paths = Path(os.path.join(self.data_dir, "pset")).glob("*.ifc")
         for path in property_paths:
-            self.property_files.append(ifcopenshell.open(path))
-        self.property_files.append(ifcopenshell.open(os.path.join(self.schema_dir, "Pset_IFC4_ADD2.ifc")))
+            ifcopenshell.util.pset.load_property_set_template(path)
+        ifcopenshell.util.pset.load_property_set_template(os.path.join(self.schema_dir, "Pset_IFC4_ADD2.ifc"))
 
         self.classification_files = {}
-        self.psets = {}
-        self.qtos = {}
-        self.applicable_psets = {}
-        self.applicable_qtos = {}
         self.classifications = {}
         self.load()
 
@@ -50,17 +47,6 @@ class IfcSchema:
         with open(os.path.join(self.schema_dir, "ifc_types_IFC4.json")) as f:
             self.type_map = json.load(f)
 
-        for property_file in self.property_files:
-            for prop in property_file.by_type("IfcPropertySetTemplate"):
-                if prop.Name[0:4] == "Qto_":
-                    self.qtos[prop.Name] = {"HasPropertyTemplates": {p.Name: p for p in prop.HasPropertyTemplates}}
-                    entity = prop.ApplicableEntity if prop.ApplicableEntity else "IfcRoot"
-                    self.applicable_qtos.setdefault(entity, []).append(prop.Name)
-                else:
-                    self.psets[prop.Name] = {"HasPropertyTemplates": {p.Name: p for p in prop.HasPropertyTemplates}}
-                    entity = prop.ApplicableEntity if prop.ApplicableEntity else "IfcRoot"
-                    self.applicable_psets.setdefault(entity, []).append(prop.Name)
-
     def load_classification(self, name, classification_index=None):
         if name not in self.classifications:
             if classification_index is not None:
diff --git a/src/ifcopenshell-python/ifcopenshell/util/pset.py b/src/ifcopenshell-python/ifcopenshell/util/pset.py
new file mode 100644
index 0000000000..5e5a541528
--- /dev/null
+++ b/src/ifcopenshell-python/ifcopenshell/util/pset.py
@@ -0,0 +1,39 @@
+import ifcopenshell
+
+property_set_template_files = []
+psets = {}
+qtos = {}
+applicable_psets = {}
+applicable_qtos = {}
+
+
+def load_property_set_template(path):
+    property_set_template_files.append(ifcopenshell.open(path))
+    for prop in property_set_template_files[-1].by_type("IfcPropertySetTemplate"):
+        if prop.Name[0:4] == "Qto_":
+            qtos[prop.Name] = {"HasPropertyTemplates": {p.Name: p for p in prop.HasPropertyTemplates}}
+            entity = prop.ApplicableEntity if prop.ApplicableEntity else "IfcRoot"
+            applicable_qtos.setdefault(entity, []).append(prop.Name)
+        else:
+            psets[prop.Name] = {"HasPropertyTemplates": {p.Name: p for p in prop.HasPropertyTemplates}}
+            entity = prop.ApplicableEntity if prop.ApplicableEntity else "IfcRoot"
+            applicable_psets.setdefault(entity, []).append(prop.Name)
+
+
+def get_applicable_psetqtos(schema_version, ifc_class, is_pset=False, is_qto=False):
+    def is_a(entity, ifc_class):
+        if entity.name() == ifc_class:
+            return True
+        return is_a(entity.supertype(), ifc_class) if entity.supertype() else False
+
+    results = []
+    schema = ifcopenshell.ifcopenshell_wrapper.schema_by_name(schema_version)
+    entity = schema.declaration_by_name(ifc_class)
+    if is_pset:
+        search_items = applicable_psets.items()
+    elif is_qto:
+        search_items = applicable_qtos.items()
+    for ifc_class, pset_names in search_items:
+        if is_a(entity, ifc_class):
+            results.extend(pset_names)
+    return results