diff --git a/src/blenderbim/blenderbim/bim/module/model/operator.py b/src/blenderbim/blenderbim/bim/module/model/operator.py
index 5f1ab76021..a602b5b839 100644
--- a/src/blenderbim/blenderbim/bim/module/model/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/model/operator.py
@@ -402,6 +402,7 @@ class DumbWallGenerator:
         self.relating_type = relating_type
 
     def generate(self):
+        self.file = IfcStore.get_file()
         unit_scale = ifcopenshell.util.unit.calculate_unit_scale(IfcStore.get_file())
         thicknesses = []
         for rel in self.relating_type.HasAssociations:
@@ -550,4 +551,7 @@ class DumbWallGenerator:
         self.collection.objects.link(obj)
         bpy.ops.bim.assign_class(obj=obj.name, ifc_class="IfcWall")
         bpy.ops.bim.assign_type(relating_type=self.relating_type.id(), related_object=obj.name)
+        element = self.file.by_id(obj.BIMObjectProperties.ifc_definition_id)
+        pset = ifcopenshell.api.run("pset.add_pset", self.file, product=element, Name="EPset_Parametric")
+        ifcopenshell.api.run("pset.edit_pset", self.file, pset=pset, Properties={"Engine": "BlenderBIM.DumbWall"})
         return obj
diff --git a/src/blenderbim/blenderbim/bim/module/parametric/operator.py b/src/blenderbim/blenderbim/bim/module/parametric/operator.py
index 78edab65a2..bf76155294 100644
--- a/src/blenderbim/blenderbim/bim/module/parametric/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/parametric/operator.py
@@ -1,8 +1,12 @@
 import bpy
+import bmesh
 import ifcopenshell
 import ifcopenshell.api
+import ifcopenshell.util.unit
+import ifcopenshell.util.element
 import ifcopenshell.util.representation
 from blenderbim.bim.ifc import IfcStore
+from ifcopenshell.api.pset.data import Data as PsetData
 
 
 def generate_box(usecase_path, ifc_file, **settings):
@@ -29,10 +33,48 @@ def generate_box(usecase_path, ifc_file, **settings):
         )
 
 
+def calculate_dumb_quantities(usecase_path, ifc_file, **settings):
+    unit_scale = ifcopenshell.util.unit.calculate_unit_scale(ifc_file)
+    obj = settings["blender_object"]
+    product = ifc_file.by_id(obj.BIMObjectProperties.ifc_definition_id)
+    parametric = ifcopenshell.util.element.get_psets(product).get("EPset_Parametric")
+    if not parametric or parametric["Engine"] != "BlenderBIM.DumbWall":
+        return
+    qto = ifcopenshell.api.run(
+        "pset.add_qto", ifc_file, should_run_listeners=False, product=product, Name="Qto_WallBaseQuantities"
+    )
+    length = obj.dimensions[0] / unit_scale
+    width = obj.dimensions[1] / unit_scale
+    height = obj.dimensions[2] / unit_scale
+
+    if product.HasOpenings:
+        # TODO: calculate gross / net
+        gross_volume = 0
+        net_volume = 0
+    else:
+        bm = bmesh.new()
+        bm.from_mesh(obj.data)
+        gross_volume = bm.calc_volume()
+        net_volume = gross_volume
+        bm.free()
+
+    ifcopenshell.api.run("pset.edit_qto", ifc_file, should_run_listeners=False, qto=qto, Properties={
+        "Length": round(length, 2),
+        "Width": round(width, 2),
+        "Height": round(height, 2),
+        "GrossVolume": round(gross_volume, 2),
+        "NetVolume": round(net_volume, 2)
+    })
+    PsetData.load(ifc_file, obj.BIMObjectProperties.ifc_definition_id)
+
+
 class ActivateParametricEngine(bpy.types.Operator):
     bl_idname = "bim.activate_parametric_engine"
     bl_label = "Activate Parametric Engine"
 
     def execute(self, context):
         ifcopenshell.api.add_post_listener("geometry.add_representation", IfcStore.get_file(), generate_box)
+        ifcopenshell.api.add_post_listener(
+            "geometry.add_representation", IfcStore.get_file(), calculate_dumb_quantities
+        )
         return {"FINISHED"}
diff --git a/src/ifcopenshell-python/ifcopenshell/api/geometry/add_representation.py b/src/ifcopenshell-python/ifcopenshell/api/geometry/add_representation.py
index 26c844bffc..bcb6571175 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/geometry/add_representation.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/geometry/add_representation.py
@@ -44,11 +44,11 @@ class Usecase:
         return self.create_variable_representation()
 
     def evaluate_geometry(self):
-        
+
         for modifier in self.settings["blender_object"].modifiers:
             if modifier.type == "BOOLEAN":
                 modifier.show_viewport = False
-        
+
         mesh = self.settings["blender_object"].evaluated_get(bpy.context.evaluated_depsgraph_get()).to_mesh()
         bm = bmesh.new()
         bm.from_mesh(mesh)
@@ -57,23 +57,22 @@ class Usecase:
         if not self.settings["should_force_triangulation"]:
             bmesh.ops.dissolve_limit(
                 bm,
-                angle_limit=0.00174533,
+                angle_limit=0.00174533,  # 1 degree
                 use_dissolve_boundaries=False,
                 verts=bm.verts[:],
                 edges=bm.edges[:],
-                delimit={'MATERIAL'}
+                delimit={"MATERIAL"},
             )
         bm.to_mesh(mesh)
         bm.free()
         del bm
 
         self.settings["geometry"] = mesh
-        
+
         for modifier in self.settings["blender_object"].modifiers:
             if modifier.type == "BOOLEAN":
                 modifier.show_viewport = True
 
-                
     def create_model_representation(self):
         if self.settings["context"].is_a() == "IfcGeometricRepresentationContext":
             return self.create_variable_representation()
@@ -200,7 +199,7 @@ class Usecase:
                 "XLength": self.convert_si_to_unit(width),
                 "YLength": self.convert_si_to_unit(height),
                 "ZLength": self.convert_si_to_unit(self.settings["geometry"].clip_end),
-            }
+            },
         )
 
         return self.file.createIfcShapeRepresentation(