Update Readme and write file

README.md

@@ -12,6 +12,7 @@ The exporter receives a Speckle model version, walks its object tree, and produc
 - Revit property sets (Common psets, instance/type parameters, material quantities)
 - IFC type objects (IfcWallType, IfcSlabType, etc.) shared across instances
 - Spatial structure (IfcProject > IfcSite > IfcBuilding > IfcBuildingStorey)
+- IfcSpace elements aggregated under storeys with Room properties
 
 ## Pipeline Overview
 
@@ -33,7 +34,7 @@ Speckle Model
     │   ├── Classify → IFC entity class
     │   ├── Convert geometry → IfcPolygonalFaceSet
     │   ├── Create IFC element + placement
-    │   ├── Write property sets
+    │   ├── Write property sets & quantities
     │   └── Assign IFC type object
     │
     ▼
@@ -52,19 +53,19 @@ Speckle Model
 | `utils/mapper.py` | Classifies Speckle objects into IFC entity types |
 | `utils/geometry.py` | Converts Speckle meshes to IfcPolygonalFaceSet geometry |
 | `utils/instances.py` | Handles InstanceProxy objects with shared geometry (IfcMappedItem) |
-| `utils/properties.py` | Writes IFC property sets from Revit parameters |
+| `utils/properties.py` | Writes IFC property sets and quantities from Revit parameters |
 | `utils/type_manager.py` | Creates and caches IfcTypeObjects (IfcWallType, etc.) |
 | `utils/materials.py` | Maps Speckle render materials to IfcSurfaceStyle colours |
 | `utils/writer.py` | Creates the IFC file scaffold and manages storey creation |
-| `utils/config.py` | Project/site/building name configuration |
+| `utils/receiver.py` | Connects to Speckle server and receives model data (uses `.env`) |
 
 ## Mapping Logic
 
-Classification of Speckle objects to IFC entity types follows a priority chain with three lookup tables. The first match wins.
+Classification of Speckle objects to IFC entity types follows a priority chain. The first match wins.
 
 ### Priority 1: `builtInCategory` (OST_ enum)
 
-The most reliable source. Read from `obj.properties.builtInCategory`, which contains the Revit `BuiltInCategory` enum value. This is a direct Revit classification and maps unambiguously to IFC.
+The most reliable source. Read from `obj.properties.builtInCategory`, which contains the Revit `BuiltInCategory` enum value.
 
 Examples:
 | builtInCategory | IFC Class |
@@ -81,23 +82,11 @@ Examples:
 | `OST_PipeCurves` | `IfcPipeSegment` |
 | `OST_LightingFixtures` | `IfcLightFixture` |
 | `OST_Furniture` | `IfcFurnishingElement` |
+| `OST_Rooms` | `IfcSpace` |
 
 The full table covers ~70 Revit categories across Architectural, Structural, MEP (HVAC, Plumbing, Electrical), and Site/Civil disciplines.
 
-### Priority 2: `speckle_type` prefix
-
-For typed Speckle objects, the `speckle_type` string is matched. Exact match is tried first, then longest-prefix match.
-
-Examples:
-| speckle_type | IFC Class |
-|---|---|
-| `Objects.BuiltElements.Wall` | `IfcWall` |
-| `Objects.BuiltElements.Floor` | `IfcSlab` |
-| `Objects.BuiltElements.Revit.RevitWall` | `IfcWall` |
-| `Objects.BuiltElements.Revit.RevitColumn` | `IfcColumn` |
-| `Objects.Geometry.Mesh` | `IfcBuildingElementProxy` |
-
-### Priority 3: Category name (display string)
+### Priority 2: Category name (display string)
 
 The category name from the traversal context (the name of the parent Collection in the Speckle tree). Exact match first, then case-insensitive substring match.
 
@@ -109,9 +98,9 @@ Examples:
 | `Plumbing Fixtures` | `IfcSanitaryTerminal` |
 | `Lighting Fixtures` | `IfcLightFixture` |
 
-### Priority 4: `obj.category` field
+### Priority 3: `obj.category` field
 
-Same lookup as Priority 3, but using the object's own `category` attribute.
+Same lookup as Priority 2, but using the object's own `category` attribute.
 
 ### Fallback
 
@@ -136,7 +125,11 @@ Speckle `InstanceProxy` objects reference shared definition geometry via `defini
 - **Revit format**: `definitionId` is a 64-char hex hash; geometry is found by walking the object tree
 - **IFC format**: `definitionId` starts with `DEFINITION:`; geometry is in `definitionGeometry` collection
 
-Performance optimisation: geometry is built once as an `IfcRepresentationMap`, then each instance references it via `IfcMappedItem` + `IfcCartesianTransformationOperator3DnonUniform`. This avoids duplicating vertex data across hundreds of identical elements (e.g. chairs, light fixtures, curtain wall panels).
+Performance optimisation: geometry is built once as an `IfcRepresentationMap`, then each instance references it via `IfcMappedItem` + `IfcCartesianTransformationOperator3DnonUniform`. This avoids duplicating vertex data across hundreds of identical elements.
+
+### Composite Objects (Path B2 — merged instances)
+
+Objects like Windows and Doors may have multiple `InstanceProxy` items in their `displayValue` (e.g. frame, glass, sill). These are **not** separate IFC elements — all instance geometries are merged into a single `IfcShapeRepresentation` with combined `IfcMappedItem` entries, producing one IFC element per Speckle object.
 
 ## Property Sets
 
@@ -145,11 +138,44 @@ The exporter writes property sets matching Revit's native IFC export structure:
 | Property Set | Content |
 |---|---|
 | `Pset_<Entity>Common` | Standard IFC properties: Reference, IsExternal, LoadBearing, ThermalTransmittance |
-| `RVT_TypeParameters` | All Revit type parameters (written on the IfcTypeObject) |
+| `Pset_SpaceCommon` | Room-specific: Reference, RoomNumber, RoomName, Category (Occupant) |
 | `RVT_InstanceParameters` | All Revit instance parameters |
 | `RVT_Identity` | Family, Type, ElementId, BuiltInCategory |
-| `Qto_<MaterialName>` | Material quantities: area, volume, density |
 
+## Quantities
+
+Quantities follow the IFC standard naming convention: `Qto_<EntityType>BaseQuantities` and `Qto_<MaterialName>BaseQuantities`.
+
+| Quantity Set | Content |
+|---|---|
+| `Qto_<EntityType>BaseQuantities` | Element-level quantities from Revit computed parameters (area, volume, length, width, height, perimeter) |
+| `Qto_SpaceBaseQuantities` | Room quantities: NetFloorArea, NetVolume |
+| `Qto_<MaterialName>BaseQuantities` | Per-material quantities: GrossArea, GrossVolume, Density |
+
+### Element Quantity Mapping
+
+| IFC Quantity | Revit Parameter(s) |
+|---|---|
+| GrossArea | `HOST_AREA_COMPUTED` |
+| GrossVolume | `HOST_VOLUME_COMPUTED` |
+| Length | `CURVE_ELEM_LENGTH`, `INSTANCE_LENGTH_PARAM` |
+| Height | `WALL_USER_HEIGHT_PARAM`, `FAMILY_HEIGHT_PARAM`, `INSTANCE_HEAD_HEIGHT_PARAM` |
+| Width | `INSTANCE_WIDTH_PARAM`, `FURNITURE_WIDTH`, `FLOOR_ATTR_THICKNESS_PARAM` |
+| Perimeter | `HOST_PERIMETER_COMPUTED` |
+
+### Supported Entity Qto Sets
+
+`Qto_WallBaseQuantities`, `Qto_SlabBaseQuantities`, `Qto_ColumnBaseQuantities`, `Qto_BeamBaseQuantities`, `Qto_DoorBaseQuantities`, `Qto_WindowBaseQuantities`, `Qto_RoofBaseQuantities`, `Qto_CoveringBaseQuantities`, `Qto_RailingBaseQuantities`, `Qto_StairBaseQuantities`, `Qto_RampBaseQuantities`, `Qto_MemberBaseQuantities`, `Qto_FootingBaseQuantities`, `Qto_CurtainWallBaseQuantities`, `Qto_BuildingElementProxyBaseQuantities`
+
+## IfcSpace (Rooms)
+
+Revit Rooms (`OST_Rooms`) are exported as `IfcSpace` elements with special handling:
+
+- **Spatial relationship**: Aggregated under `IfcBuildingStorey` via `IfcRelAggregates` (not contained)
+- **Naming**: Uses the Speckle object `name` attribute (not Family:Type which is "none:none" for rooms)
+- **IfcSpace.Name**: Set to `ROOM_NUMBER`
+- **IfcSpace.LongName**: Set to `ROOM_NAME`
+- **Geometry**: Converted from `displayValue` meshes like any other element
 
 ## Function Inputs
 
@@ -160,6 +186,16 @@ The exporter writes property sets matching Revit's native IFC export structure:
 | `IFC_SITE_NAME` | Name for the IfcSite entity |
 | `IFC_BUILDING_NAME` | Name for the IfcBuilding entity |
 
+## Environment Variables
+
+For local testing via `receiver.py`, configure a `.env` file:
+
+| Variable | Description |
+|---|---|
+| `SPECKLE_SERVER_URL` | Speckle server URL (default: `https://app.speckle.systems`) |
+| `SPECKLE_TOKEN` | Personal access token for authentication |
+| `SPECKLE_PROJECT_ID` | Project (stream) ID |
+
 ## Testing
 
 | Model Name                      | Revit Size | IFC Size | Conversion Time |

flatten.py

@@ -1,27 +0,0 @@
-"""Helper module for a simple speckle object tree flattening."""
-
-from collections.abc import Iterable
-
-from specklepy.objects import Base
-
-
-def flatten_base(base: Base) -> Iterable[Base]:
-    """Flatten a base object into an iterable of bases.
-
-    This function recursively traverses the `elements` or `@elements` attribute of the
-    base object, yielding each nested base object.
-
-    Args:
-        base (Base): The base object to flatten.
-
-    Yields:
-        Base: Each nested base object in the hierarchy.
-    """
-    # Attempt to get the elements attribute, fallback to @elements if necessary
-    elements = getattr(base, "elements", getattr(base, "@elements", None))
-
-    if elements is not None:
-        for element in elements:
-            yield from flatten_base(element)
-
-    yield base

main.py

@@ -162,26 +162,37 @@ def automate_function(
                 total += 1
 
             # B2: Instance objects nested inside displayValue
-            # Each becomes its own IFC element (same class as parent)
-            # Use the parent object's name — the InstanceProxy has no meaningful name
+            # All instances are parts of the SAME element (e.g. window frame + glass + sill)
+            # Merge all into a single IFC element with combined geometry
             nested_instances = get_display_instances(obj)
-            for inst in nested_instances:
-                inst_rep, inst_placement = instance_to_ifc(
-                    ifc, body_context, inst, definition_map, scale=scale, material_manager=material_manager
-                )
-                if not inst_rep:
-                    no_geometry += 1
-                    continue
-                inst_element = _create_element(
-                    ifc, ifc_class, name, inst_rep, inst_placement, storey,
-                    storey_manager=storey_manager,
-                    tag=get_element_tag(obj), guid=None,
-                    object_type=getattr(obj, "type", None),
-                )
-                write_properties(ifc, inst_element, obj, ifc_class=ifc_class, category_name=category_name)
-                type_manager.assign(inst_element, obj, ifc_class)
-                instance_count += 1
-                total += 1
+            if nested_instances:
+                mapped_items = []
+                inst_placement = None
+                for inst in nested_instances:
+                    inst_rep, inst_pl = instance_to_ifc(
+                        ifc, body_context, inst, definition_map, scale=scale, material_manager=material_manager
+                    )
+                    if inst_rep:
+                        mapped_items.extend(inst_rep.Items)
+                        if inst_placement is None:
+                            inst_placement = inst_pl
+                if mapped_items:
+                    combined_rep = ifc.createIfcShapeRepresentation(
+                        ContextOfItems=body_context,
+                        RepresentationIdentifier="Body",
+                        RepresentationType="MappedRepresentation",
+                        Items=mapped_items,
+                    )
+                    element = _create_element(
+                        ifc, ifc_class, name, combined_rep, inst_placement, storey,
+                        storey_manager=storey_manager,
+                        tag=get_element_tag(obj), guid=get_ifc_guid(obj),
+                        object_type=getattr(obj, "type", None),
+                    )
+                    write_properties(ifc, element, obj, ifc_class=ifc_class, category_name=category_name)
+                    type_manager.assign(element, obj, ifc_class)
+                    instance_count += 1
+                    total += 1
 
             # Track if neither path produced geometry
             if not rep and not nested_instances:
@@ -205,12 +216,12 @@ def automate_function(
 
     ifc.write(ifc_filename)
     print(f"\n💾 IFC file written: {ifc_filename}")
-    # try:
-    #     automate_context.mark_run_success("Success! You can download the IF file below.")
-    #     automate_context.store_file_result(f"./{ifc_filename}")
-    # except Exception as e:
-    #     print(f"  ⚠️  Could not upload file result (network issue?): {e}")
-    #     automate_context.mark_run_failed(f"Something went wrong when storing file result. Exception detail: {e}") 
+    try:
+        automate_context.mark_run_success("Success! You can download the IF file below.")
+        automate_context.store_file_result(f"./{ifc_filename}")
+    except Exception as e:
+        print(f"  ⚠️  Could not upload file result (network issue?): {e}")
+        automate_context.mark_run_failed(f"Something went wrong when storing file result. Exception detail: {e}") 
 
     print(f"\n{'=' * 60}")
     print(f"  Export complete!")

utils/mapper.py

@@ -4,9 +4,8 @@
 #
 # Strategy (priority order):
 #   1. builtInCategory (OST_ enum from properties.builtInCategory) — most reliable
-#   2. speckle_type prefix match — for typed Speckle objects
-#   3. category_name string (traversal context) — display name fallback
-#   4. IfcBuildingElementProxy — last resort
+#   2. category_name string (traversal context) — display name fallback
+#   3. IfcBuildingElementProxy — last resort
 #
 # builtInCategory values: https://www.revitapidocs.com/2019/ba1c5b30-242f-5fdc-8ea9-ec3b61e6e722.htm
 # =============================================================================
@@ -119,44 +118,7 @@ BUILTIN_CATEGORY_MAP: dict[str, str] = {
 }
 
 
-# --- speckle_type → IFC class (secondary lookup) ---
-SPECKLE_TYPE_MAP: dict[str, str] = {
-    "Objects.BuiltElements.Wall":                        "IfcWall",
-    "Objects.BuiltElements.Floor":                       "IfcSlab",
-    "Objects.BuiltElements.Roof":                        "IfcRoof",
-    "Objects.BuiltElements.Column":                      "IfcColumn",
-    "Objects.BuiltElements.Beam":                        "IfcBeam",
-    "Objects.BuiltElements.Brace":                       "IfcMember",
-    "Objects.BuiltElements.Duct":                        "IfcDuctSegment",
-    "Objects.BuiltElements.Pipe":                        "IfcPipeSegment",
-    "Objects.BuiltElements.Wire":                        "IfcCableCarrierSegment",
-    "Objects.BuiltElements.Opening":                     "IfcOpeningElement",
-    "Objects.BuiltElements.Room":                        "IfcSpace",
-    "Objects.BuiltElements.Ceiling":                     "IfcCovering",
-    "Objects.BuiltElements.Stair":                       "IfcStair",
-    "Objects.BuiltElements.Ramp":                        "IfcRamp",
-    "Objects.BuiltElements.Foundation":                  "IfcFooting",
-    "Objects.BuiltElements.Grid":                        "IfcGrid",
-    "Objects.BuiltElements.Level":                       "IfcBuildingStorey",
-    "Objects.BuiltElements.Revit.RevitWall":             "IfcWall",
-    "Objects.BuiltElements.Revit.RevitFloor":            "IfcSlab",
-    "Objects.BuiltElements.Revit.RevitRoof":             "IfcRoof",
-    "Objects.BuiltElements.Revit.RevitColumn":           "IfcColumn",
-    "Objects.BuiltElements.Revit.RevitBeam":             "IfcBeam",
-    "Objects.BuiltElements.Revit.RevitBrace":            "IfcMember",
-    "Objects.BuiltElements.Revit.RevitDuct":             "IfcDuctSegment",
-    "Objects.BuiltElements.Revit.RevitPipe":             "IfcPipeSegment",
-    "Objects.BuiltElements.Revit.RevitRoom":             "IfcSpace",
-    "Objects.BuiltElements.Revit.RevitStair":            "IfcStair",
-    "Objects.BuiltElements.Revit.RevitRailing":          "IfcRailing",
-    "Objects.BuiltElements.Revit.RevitCeiling":          "IfcCovering",
-    "Objects.BuiltElements.Revit.RevitTopography":       "IfcGeographicElement",
-    "Objects.BuiltElements.Revit.RevitElementType":      "IfcBuildingElementProxy",
-    "Objects.Geometry.Mesh":                             "IfcBuildingElementProxy",
-    "Objects.Geometry.Brep":                             "IfcBuildingElementProxy",
-}
-
-# --- Display category name → IFC class (tertiary fallback) ---
+# --- Display category name → IFC class (secondary fallback) ---
 CATEGORY_MAP: dict[str, str] = {
     "Walls":                        "IfcWall",
     "Floors":                       "IfcSlab",
@@ -235,11 +197,6 @@ def _get_builtin_category(obj) -> str | None:
     return result
 
 
-# Pre-computed: sorted prefixes longest-first for early exit on prefix match
-_SPECKLE_PREFIXES: list[tuple[str, str]] = sorted(
-    SPECKLE_TYPE_MAP.items(), key=lambda x: len(x[0]), reverse=True
-)
-
 # Pre-computed lowercase category map for substring matching
 _CATEGORY_MAP_LOWER: list[tuple[str, str]] = [
     (k.lower(), v) for k, v in CATEGORY_MAP.items()
@@ -255,10 +212,9 @@ def classify(obj, category_name: str = "") -> str:
 
     Priority:
       1. properties.builtInCategory (OST_ enum) — definitive Revit classification
-      2. speckle_type prefix match
-      3. category_name from traversal context (display string)
-      4. obj.category field
-      5. IfcBuildingElementProxy fallback
+      2. category_name from traversal context (display string)
+      3. obj.category field
+      4. IfcBuildingElementProxy fallback
     """
     cache_key = (id(obj), category_name)
     if cache_key in _classify_cache:
@@ -275,16 +231,7 @@ def _classify_impl(obj, category_name: str) -> str:
     if bic and bic in BUILTIN_CATEGORY_MAP:
         return BUILTIN_CATEGORY_MAP[bic]
 
-    # 2. speckle_type — exact match first, then longest-prefix match
-    speckle_type = getattr(obj, "speckle_type", "") or ""
-    if speckle_type:
-        if speckle_type in SPECKLE_TYPE_MAP:
-            return SPECKLE_TYPE_MAP[speckle_type]
-        for prefix, ifc_class in _SPECKLE_PREFIXES:
-            if speckle_type.startswith(prefix):
-                return ifc_class
-
-    # 3. category_name from traversal context — exact match first
+    # 2. category_name from traversal context — exact match first
     if category_name:
         if category_name in CATEGORY_MAP:
             return CATEGORY_MAP[category_name]
@@ -293,7 +240,7 @@ def _classify_impl(obj, category_name: str) -> str:
             if key_lower in cat_lower:
                 return ifc_class
 
-    # 4. obj.category field
+    # 3. obj.category field
     obj_category = getattr(obj, "category", None)
     if obj_category and isinstance(obj_category, str):
         if obj_category in CATEGORY_MAP:

utils/properties.py

@@ -644,7 +644,7 @@ def write_material_quantities(ifc, element, obj: Base):
     Source: properties."Material Quantities".<MaterialName>.{area, volume, density,
             materialName, materialClass, materialCategory}
 
-    Each material produces one IfcElementQuantity named "Qto_<MaterialName>" with:
+    Each material produces one IfcElementQuantity named "Qto_<MaterialName>BaseQuantities" with:
       - GrossArea      (IfcQuantityArea)
       - GrossVolume    (IfcQuantityVolume)
       - Density        (IfcPropertySingleValue — no standard IFC quantity type)
@@ -711,7 +711,7 @@ def write_material_quantities(ifc, element, obj: Base):
             continue
 
         # Create IfcElementQuantity and link via IfcRelDefinesByProperties
-        qto_name = f"Qto_{mat_name}"
+        qto_name = f"Qto_{mat_name}BaseQuantities"
         try:
             qto = ifcopenshell.api.run(
                 "pset.add_qto", ifc,
@@ -723,6 +723,103 @@ def write_material_quantities(ifc, element, obj: Base):
             print(f"  ⚠️  {qto_name}: {e}")
 
 
+# ---------------------------------------------------------------------------
+# Qto_<EntityType>BaseQuantities — standard element-level quantities
+# ---------------------------------------------------------------------------
+
+# IFC entity → Qto name (only entities with standard Qto sets)
+_ENTITY_QTO_NAME: dict[str, str] = {
+    "IfcWall":                      "Qto_WallBaseQuantities",
+    "IfcWallStandardCase":          "Qto_WallBaseQuantities",
+    "IfcSlab":                      "Qto_SlabBaseQuantities",
+    "IfcColumn":                    "Qto_ColumnBaseQuantities",
+    "IfcBeam":                      "Qto_BeamBaseQuantities",
+    "IfcDoor":                      "Qto_DoorBaseQuantities",
+    "IfcWindow":                    "Qto_WindowBaseQuantities",
+    "IfcRoof":                      "Qto_RoofBaseQuantities",
+    "IfcCovering":                  "Qto_CoveringBaseQuantities",
+    "IfcRailing":                   "Qto_RailingBaseQuantities",
+    "IfcStair":                     "Qto_StairBaseQuantities",
+    "IfcRamp":                      "Qto_RampBaseQuantities",
+    "IfcMember":                    "Qto_MemberBaseQuantities",
+    "IfcFooting":                   "Qto_FootingBaseQuantities",
+    "IfcCurtainWall":               "Qto_CurtainWallBaseQuantities",
+    "IfcBuildingElementProxy":      "Qto_BuildingElementProxyBaseQuantities",
+}
+
+# IFC quantity name → (IFC entity type, value attribute, [Revit param fallbacks])
+# First matching Revit param wins for each quantity name.
+_ELEMENT_QUANTITY_DEFS: list[tuple[str, str, str, list[str]]] = [
+    ("GrossArea",   "IfcQuantityArea",   "AreaValue",   ["HOST_AREA_COMPUTED"]),
+    ("GrossVolume", "IfcQuantityVolume",  "VolumeValue", ["HOST_VOLUME_COMPUTED"]),
+    ("Length",      "IfcQuantityLength",  "LengthValue", [
+        "CURVE_ELEM_LENGTH", "INSTANCE_LENGTH_PARAM",
+    ]),
+    ("Height",      "IfcQuantityLength",  "LengthValue", [
+        "WALL_USER_HEIGHT_PARAM", "FAMILY_HEIGHT_PARAM",
+        "INSTANCE_HEAD_HEIGHT_PARAM",
+    ]),
+    ("Width",       "IfcQuantityLength",  "LengthValue", [
+        "INSTANCE_WIDTH_PARAM", "FURNITURE_WIDTH",
+        "FLOOR_ATTR_THICKNESS_PARAM",
+    ]),
+    ("Perimeter",   "IfcQuantityLength",  "LengthValue", [
+        "HOST_PERIMETER_COMPUTED",
+    ]),
+]
+
+
+def write_element_quantities(ifc, element, obj: Base, ifc_class: str = ""):
+    """
+    Write Qto_<EntityType>BaseQuantities from Revit computed instance parameters.
+
+    Reads HOST_AREA_COMPUTED, HOST_VOLUME_COMPUTED, CURVE_ELEM_LENGTH,
+    FURNITURE_WIDTH, FAMILY_HEIGHT_PARAM, etc.
+    IfcSpace is handled separately in _write_space_properties.
+    """
+    if ifc_class == "IfcSpace":
+        return  # Already handled by Qto_SpaceBaseQuantities
+
+    qto_name = _ENTITY_QTO_NAME.get(ifc_class)
+    if not qto_name:
+        return
+
+    props = _get_props_dict(obj)
+    params = _safe_get(props, "Parameters", {})
+    inst_params = _safe_get(params, "Instance Parameters", {})
+    if not inst_params:
+        return
+
+    quantities = []
+
+    for qty_name, ifc_entity, value_attr, revit_params in _ELEMENT_QUANTITY_DEFS:
+        val = None
+        for internal_name in revit_params:
+            val = _param_value(inst_params, internal_name)
+            if val is not None:
+                break
+        if val is None:
+            continue
+        try:
+            q = ifc.create_entity(ifc_entity, Name=qty_name, **{value_attr: float(val)})
+            quantities.append(q)
+        except Exception:
+            pass
+
+    if not quantities:
+        return
+
+    try:
+        qto = ifcopenshell.api.run(
+            "pset.add_qto", ifc,
+            product=element,
+            name=qto_name,
+        )
+        qto.Quantities = quantities
+    except Exception as e:
+        print(f"  ⚠️  {qto_name}: {e}")
+
+
 def write_properties(ifc, element, obj: Base, ifc_class: str = "", category_name: str = ""):
     """
     Write all property sets for an IFC element, matching Revit native IFC export structure:
@@ -731,10 +828,12 @@ def write_properties(ifc, element, obj: Base, ifc_class: str = "", category_name
       3. RVT_TypeParameters       — all remaining Revit type parameters
       4. RVT_InstanceParameters   — all remaining Revit instance parameters
       5. RVT_Identity             — family, type, elementId, builtInCategory
-      6. Qto_<MaterialName>       — material quantities (area, volume, density)
+      6. Qto_<EntityType>BaseQuantities   — element-level quantities (area, volume, length)
+      7. Qto_<MaterialName>BaseQuantities — material quantities (area, volume, density)
     """
     write_common_pset(ifc, element, obj, ifc_class, category_name)
     write_revit_params(ifc, element, obj)
+    write_element_quantities(ifc, element, obj, ifc_class)
     write_material_quantities(ifc, element, obj)