Validate face indices without exception control flow

Added project status section indicating active development.

README.md

@@ -1,6 +1,10 @@
-# Speckle to IFC 4.3 Exporter
+# Speckle-Revit to IFC 4.3 Exporter
 
-A [Speckle Automate](https://automate.speckle.dev/) function that converts Speckle BIM models (primarily from Revit) into IFC 4.3 files using [ifcopenshell](https://ifcopenshell.org/).
+## 🚧 Project Status: WIP
+Hey there! This project is still under active development, so expect changes, bugs, and incomplete features.
+If you have any questions or suggestions, don’t hesitate to reach out at: **your@email.com**
+
+A [Speckle Automate](https://automate.speckle.dev/) function that converts Speckle Revit models into IFC 4.3 files using [ifcopenshell](https://ifcopenshell.org/). This exporter is specifically designed for models sent to Speckle from Autodesk Revit and relies on Revit-specific object structures, categories, and parameters.
 
 ## What It Does
 
@@ -8,10 +12,13 @@ The exporter receives a Speckle model version, walks its object tree, and produc
 
 - Correct IFC entity classification (IfcWall, IfcSlab, IfcColumn, etc.)
 - Tessellated geometry (IfcPolygonalFaceSet)
+- Curve geometry for Lines and Arcs (IfcGeometricCurveSet with IfcPolyline)
 - Material colours from Speckle render materials
 - 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
+- Automatic skipping of analytical/energy categories (e.g. Energy Analysis, MEP Analytical, Solar Shading)
 
 ## Pipeline Overview
 
@@ -30,10 +37,10 @@ Speckle Model
     ▼
 4. Traverse object tree
     │   For each leaf element:
-    │   ├── Classify → IFC entity class
-    │   ├── Convert geometry → IfcPolygonalFaceSet
+    │   ├── Classify → IFC entity class (skip analytical categories)
+    │   ├── Convert geometry → IfcPolygonalFaceSet or IfcGeometricCurveSet
     │   ├── Create IFC element + placement
-    │   ├── Write property sets
+    │   ├── Write property sets & quantities
     │   └── Assign IFC type object
     │
     ▼
@@ -50,21 +57,21 @@ Speckle Model
 | `main.py` | Entry point, orchestrates the full pipeline |
 | `utils/traversal.py` | Walks the Speckle Collection tree (Project > Level > Category > Element) |
 | `utils/mapper.py` | Classifies Speckle objects into IFC entity types |
-| `utils/geometry.py` | Converts Speckle meshes to IfcPolygonalFaceSet geometry |
+| `utils/geometry.py` | Converts Speckle meshes to IfcPolygonalFaceSet and Lines/Arcs to IfcGeometricCurveSet 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 |
@@ -79,25 +86,23 @@ Examples:
 | `OST_CurtainWallPanels` | `IfcCurtainWall` |
 | `OST_DuctCurves` | `IfcDuctSegment` |
 | `OST_PipeCurves` | `IfcPipeSegment` |
+| `OST_PipeFitting` | `IfcPipeFitting` |
+| `OST_PlumbingEquipment` | `IfcSanitaryTerminal` |
+| `OST_Rebar` | `IfcReinforcingBar` |
+| `OST_StructConnections` | `IfcMechanicalFastener` |
 | `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
+### Skipped Categories
 
-For typed Speckle objects, the `speckle_type` string is matched. Exact match is tried first, then longest-prefix match.
+The following analytical/energy OST categories are automatically skipped (not exported to IFC):
 
-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` |
+`OST_MEPLoadAreaSeparationLines`, `OST_EnergyAnalysisZones`, `OST_EnergyAnalysisSurface`, `OST_SolarShading`, `OST_MEPAnalyticalPipeSegments`, `OST_MEPAnalyticalDuctSegments`, `OST_MEPAnalyticalSpaces`, `OST_ElectricalConduitAnalyticalLines`, `OST_MEPLoadBoundaryLines`, `OST_FlowTerminalSeparationLines`
 
-### 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.
 
@@ -107,11 +112,13 @@ Examples:
 | `Walls` | `IfcWall` |
 | `Structural Columns` | `IfcColumn` |
 | `Plumbing Fixtures` | `IfcSanitaryTerminal` |
+| `Structural Rebar` | `IfcReinforcingBar` |
+| `Structural Connections` | `IfcMechanicalFastener` |
 | `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 +143,20 @@ 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.
+
+### Curve Geometry (Path B3)
+
+Objects whose `displayValue` contains `Objects.Geometry.Line` or `Objects.Geometry.Arc` items (and no meshes or instances) are exported as curve geometry:
+
+- **Lines** → `IfcPolyline` with start and end points
+- **Arcs** → `IfcPolyline` approximated with 8 segments, sampled parametrically from the arc's plane origin, radius, and domain angles. Falls back to start/mid/end points if plane data is unavailable.
+
+All curves are wrapped in an `IfcGeometricCurveSet` inside an `IfcShapeRepresentation` with `RepresentationType="GeometricCurveSet"`.
+
+### 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
 
@@ -145,46 +165,44 @@ 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 |
 
-## Getting Started
+## Quantities
 
-### Prerequisites
+Quantities follow the IFC standard naming convention: `Qto_<EntityType>BaseQuantities` and `Qto_<MaterialName>BaseQuantities`.
 
-- Python 3.11+
-- A Speckle account and project with a Revit model
+| 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 |
 
-### Setup
+### Element Quantity Mapping
 
-```bash
-python -m venv .venv
-# Windows
-.venv\Scripts\activate
-# macOS/Linux
-source .venv/bin/activate
+| 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` |
 
-pip install --upgrade pip
-pip install .[dev]
-```
+### Supported Entity Qto Sets
 
-### Running Locally
+`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`, `Qto_PipeFittingBaseQuantities`, `Qto_SanitaryTerminalBaseQuantities`, `Qto_ReinforcingElementBaseQuantities`, `Qto_MechanicalFastenerBaseQuantities`
 
-Configure your Speckle Automate credentials, then:
+## IfcSpace (Rooms)
 
-```bash
-python main.py
-```
+Revit Rooms (`OST_Rooms`) are exported as `IfcSpace` elements with special handling:
 
-### Deploying to Speckle Automate
-
-1. [Create](https://automate.speckle.dev/) a new Speckle Automation
-2. Select your Speckle Project and Model
-3. Select this function
-4. Configure the inputs (file name, project/site/building names)
-5. Click Create Automation
+- **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
 
@@ -195,6 +213,25 @@ python main.py
 | `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 |
+|----------------------------------|------------|----------|-----------------|
+| Huge confidential model         | 450 MB     | 391 MB   | 2h 30m          |
+| Snowdon Towers (Architecture)   | 93.2 MB    | 118 MB   | 8m 37s          |
+| Speckle Tower                   | 51 MB      | 45 MB    | 3m              |
+| Rac Basic Sample Model          | 18.8 MB    | 12 MB    | 12s             |
+
 ## Resources
 
 - [Speckle Developer Docs](https://speckle.guide/dev/python.html)

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

@@ -5,7 +5,7 @@ import ifcopenshell.api
 from utils.materials import MaterialManager
 from utils.traversal import traverse, print_tree
 from utils.mapper import classify, reset_caches as reset_mapper_caches
-from utils.geometry import mesh_to_ifc, get_display_instances, _make_placement
+from utils.geometry import mesh_to_ifc, get_display_instances, curves_to_ifc, _make_placement
 from utils.instances import is_instance, instance_to_ifc, build_definition_map, print_instance_stats, get_definition_object
 from utils.properties import write_properties, write_common_properties, build_element_name, get_element_tag, get_ifc_guid, reset_caches as reset_props_caches
 from utils.writer import create_ifc_scaffold, StoreyManager
@@ -14,7 +14,7 @@ from utils.type_manager import TypeManager
 
 SPATIAL_STRUCTURE_TYPES = {
     "IfcBuilding", "IfcBuildingStorey",
-    "IfcSpace", "IfcExternalSpatialElement", "IfcSpatialZone",
+    "IfcExternalSpatialElement", "IfcSpatialZone",
     "IfcGrid", "IfcAnnotation",
 }
 
@@ -106,11 +106,19 @@ def automate_function(
 
         ifc_class = classify(obj, category_name)
 
+        if ifc_class is None:
+            continue
+
         if ifc_class in SPATIAL_STRUCTURE_TYPES:
             skipped_spatial += 1
             continue
 
-        name   = build_element_name(obj)
+        # IfcSpace uses the Speckle object name (e.g. "Rooms - Live/Work Unit 507")
+        # instead of Family:Type (which is "none:none" for Revit rooms)
+        if ifc_class == "IfcSpace":
+            name = getattr(obj, "name", None) or build_element_name(obj)
+        else:
+            name = build_element_name(obj)
         storey = storey_manager.get_or_create(level_name)
 
         # ------------------------------------------------------------------ #
@@ -157,30 +165,52 @@ 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
+            # B3: Curve geometry (Lines, Arcs in displayValue)
             if not rep and not nested_instances:
-                no_geometry += 1
+                curve_rep, curve_placement = curves_to_ifc(ifc, body_context, obj, scale=scale, material_manager=material_manager)
+                if curve_rep:
+                    element = _create_element(ifc, ifc_class, name, curve_rep, curve_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)
+                    total += 1
+                else:
+                    no_geometry += 1
 
         if total % 100 == 0:
             print(f"  ... processed {total} elements")
@@ -200,12 +230,12 @@ 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!")
@@ -250,8 +280,10 @@ def _create_element(ifc, ifc_class, name, rep, placement, storey,
         element.ObjectPlacement = _make_placement(ifc, 0.0, 0.0, 0.0)
 
     # Queue spatial assignment (batched flush at end for performance)
+    # IfcSpace is a spatial structure element — must be decomposed (aggregated)
+    # under its IfcBuildingStorey, not spatially contained.
     if storey_manager:
-        if ifc_class == "IfcSite":
+        if ifc_class in ("IfcSite", "IfcSpace"):
             storey_manager.queue_aggregate(storey, element)
         else:
             storey_manager.queue_contain(storey, element)

pyproject.toml

@@ -9,7 +9,7 @@ readme = "README.md"
 license = "Apache-2.0"
 keywords = ["speckle", "automate", "bim", "aec", "ifc", "export", "revit"]
 
-dependencies = ["specklepy==3.2.4",
+dependencies = ["specklepy==3.1.0",
 		"ifcopenshell==0.8.4.post1",
 		"python-dotenv>=1.0.0",]
 

utils/geometry.py

@@ -11,6 +11,8 @@
 #     for compact output — each vertex stored once, not once per face.
 # =============================================================================
 
+import math
+
 import ifcopenshell
 from specklepy.objects.base import Base
 
@@ -53,34 +55,47 @@ def build_ifc_facesets(ifc, verts_scaled: list, face_groups: list) -> list:
 
     # Validate faces and remap indices to deduplicated vertex list
     valid_faces = []  # list of (idx0+1, idx1+1, ...) tuples (1-based for IFC)
+    vert_len = len(verts_scaled)
     for indices in face_groups:
-        try:
-            remapped = []
-            seen_snaps = set()
-            degenerate = False
-
-            for i in indices:
-                i3 = i * 3
-                x = verts_scaled[i3]
-                y = verts_scaled[i3 + 1]
-                z = verts_scaled[i3 + 2]
-                key = (round(x * inv_tol), round(y * inv_tol), round(z * inv_tol))
-                if key in seen_snaps:
-                    degenerate = True
-                    break
-                seen_snaps.add(key)
-                idx = snap_to_idx.get(key)
-                if idx is None:
-                    idx = len(deduped_verts)
-                    snap_to_idx[key] = idx
-                    deduped_verts.append([x, y, z])
-                remapped.append(idx + 1)  # 1-based for IFC
-
-            if degenerate or len(remapped) < 3:
-                continue
-            valid_faces.append(remapped)
-        except Exception:
+        if indices is None:
             continue
+        if not isinstance(indices, (list, tuple)):
+            continue
+
+        remapped = []
+        seen_snaps = set()
+        degenerate = False
+        invalid = False
+
+        for i in indices:
+            if not isinstance(i, int):
+                invalid = True
+                break
+
+            i3 = i * 3
+            if i3 < 0 or i3 + 2 >= vert_len:
+                invalid = True
+                break
+
+            x = verts_scaled[i3]
+            y = verts_scaled[i3 + 1]
+            z = verts_scaled[i3 + 2]
+            key = (round(x * inv_tol), round(y * inv_tol), round(z * inv_tol))
+            if key in seen_snaps:
+                degenerate = True
+                break
+            seen_snaps.add(key)
+
+            idx = snap_to_idx.get(key)
+            if idx is None:
+                idx = len(deduped_verts)
+                snap_to_idx[key] = idx
+                deduped_verts.append([x, y, z])
+            remapped.append(idx + 1)  # 1-based for IFC
+
+        if invalid or degenerate or len(remapped) < 3:
+            continue
+        valid_faces.append(remapped)
 
     if not valid_faces or not deduped_verts:
         return []
@@ -245,6 +260,181 @@ def get_display_instances(obj: Base) -> list:
     return instances
 
 
+# --------------------------------------------------------------------------- #
+# Curve detection & extraction (Lines, Arcs)
+# --------------------------------------------------------------------------- #
+
+def _is_line(item) -> bool:
+    """Detect Objects.Geometry.Line (but not Polyline)."""
+    if item is None:
+        return False
+    st = _get(item, "speckle_type") or ""
+    return "Line" in st and "Polyline" not in st
+
+
+def _is_arc(item) -> bool:
+    """Detect Objects.Geometry.Arc."""
+    if item is None:
+        return False
+    st = _get(item, "speckle_type") or ""
+    return "Arc" in st
+
+
+def get_display_curves(obj: Base) -> list:
+    """Extract Line and Arc objects from a DataObject's displayValue."""
+    curves = []
+    for key in ["displayValue", "@displayValue"]:
+        display = _get(obj, key)
+        if display is None:
+            continue
+        items = display if isinstance(display, list) else [display]
+        for item in items:
+            if _is_line(item) or _is_arc(item):
+                curves.append(item)
+        if curves:
+            break
+    return curves
+
+
+def _point_coords(pt, fallback_scale: float) -> tuple:
+    """Extract (x, y, z) from a Speckle Point, scaled to mm."""
+    scale = _resolve_scale(pt, fallback_scale)
+    x = float(_get(pt, "x") or 0.0) * scale
+    y = float(_get(pt, "y") or 0.0) * scale
+    z = float(_get(pt, "z") or 0.0) * scale
+    return x, y, z
+
+
+def _arc_to_points(arc, scale: float, num_segments: int = 8) -> list:
+    """
+    Approximate a Speckle Arc as a list of (x, y, z) points in mm.
+    Uses plane origin (center), radius, and domain angles for parametric sampling.
+    Falls back to start/mid/end points if plane data is missing.
+    """
+    plane = _get(arc, "plane")
+    radius = _get(arc, "radius")
+    domain = _get(arc, "domain")
+
+    if not plane or not radius or not domain:
+        points = []
+        for key in ["startPoint", "midPoint", "endPoint"]:
+            pt = _get(arc, key)
+            if pt:
+                points.append(_point_coords(pt, scale))
+        return points if len(points) >= 2 else []
+
+    origin = _get(plane, "origin")
+    xdir = _get(plane, "xdir")
+    ydir = _get(plane, "ydir")
+
+    if not origin or not xdir or not ydir:
+        points = []
+        for key in ["startPoint", "midPoint", "endPoint"]:
+            pt = _get(arc, key)
+            if pt:
+                points.append(_point_coords(pt, scale))
+        return points if len(points) >= 2 else []
+
+    cx, cy, cz = _point_coords(origin, scale)
+    # Direction vectors are unitless — do not scale
+    dxx = float(_get(xdir, "x") or 0.0)
+    dxy = float(_get(xdir, "y") or 0.0)
+    dxz = float(_get(xdir, "z") or 0.0)
+    dyx = float(_get(ydir, "x") or 0.0)
+    dyy = float(_get(ydir, "y") or 0.0)
+    dyz = float(_get(ydir, "z") or 0.0)
+
+    r = float(radius) * scale
+    t_start = float(_get(domain, "start") or 0.0)
+    t_end = float(_get(domain, "end") or 0.0)
+
+    points = []
+    for i in range(num_segments + 1):
+        t = t_start + (t_end - t_start) * i / num_segments
+        cos_t = math.cos(t)
+        sin_t = math.sin(t)
+        x = cx + r * (cos_t * dxx + sin_t * dyx)
+        y = cy + r * (cos_t * dxy + sin_t * dyy)
+        z = cz + r * (cos_t * dxz + sin_t * dyz)
+        points.append((x, y, z))
+    return points
+
+
+def curves_to_ifc(
+    ifc: ifcopenshell.file,
+    body_context,
+    obj: Base,
+    scale: float = 0.001,
+    material_manager=None,
+) -> tuple:
+    """
+    Convert Speckle Line/Arc objects in displayValue to IFC curve geometry.
+    Lines → IfcPolyline (2 points), Arcs → IfcPolyline (sampled points).
+    Wrapped in IfcGeometricCurveSet.
+    Returns (IfcShapeRepresentation, IfcLocalPlacement) or (None, None).
+    """
+    curves = get_display_curves(obj)
+    if not curves:
+        return None, None
+
+    obj_scale = _resolve_scale(obj, scale)
+    polylines = []
+    all_points = []
+
+    for curve in curves:
+        cs = _resolve_scale(curve, obj_scale)
+
+        if _is_line(curve):
+            start = _get(curve, "start")
+            end = _get(curve, "end")
+            if not start or not end:
+                continue
+            p1 = _point_coords(start, cs)
+            p2 = _point_coords(end, cs)
+            all_points.extend([p1, p2])
+            polylines.append([p1, p2])
+
+        elif _is_arc(curve):
+            pts = _arc_to_points(curve, cs)
+            if len(pts) >= 2:
+                all_points.extend(pts)
+                polylines.append(pts)
+
+    if not polylines or not all_points:
+        return None, None
+
+    # Compute origin from all curve points
+    xs = [p[0] for p in all_points]
+    ys = [p[1] for p in all_points]
+    zs = [p[2] for p in all_points]
+    ox = (min(xs) + max(xs)) / 2.0
+    oy = (min(ys) + max(ys)) / 2.0
+    oz = min(zs)
+
+    # Build IfcPolylines offset from origin
+    ifc_polylines = []
+    for pts in polylines:
+        ifc_points = [
+            ifc.createIfcCartesianPoint([p[0] - ox, p[1] - oy, p[2] - oz])
+            for p in pts
+        ]
+        ifc_polylines.append(ifc.createIfcPolyline(ifc_points))
+
+    if not ifc_polylines:
+        return None, None
+
+    curve_set = ifc.createIfcGeometricCurveSet(ifc_polylines)
+
+    rep = ifc.createIfcShapeRepresentation(
+        ContextOfItems=body_context,
+        RepresentationIdentifier="Body",
+        RepresentationType="GeometricCurveSet",
+        Items=[curve_set],
+    )
+    placement = _make_placement(ifc, ox, oy, oz)
+    return rep, placement
+
+
 # --------------------------------------------------------------------------- #
 # Face decoding
 # --------------------------------------------------------------------------- #

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
 # =============================================================================
@@ -63,6 +62,7 @@ BUILTIN_CATEGORY_MAP: dict[str, str] = {
     "OST_StructuralStiffener":              "IfcMember",
     "OST_StructuralTruss":                  "IfcMember",
     "OST_StructuralConnectionModel":        "IfcMechanicalFastener",
+    "OST_StructConnections":                "IfcMechanicalFastener",
     "OST_Rebar":                            "IfcReinforcingBar",
     "OST_FabricAreas":                      "IfcReinforcingMesh",
     "OST_FabricReinforcement":              "IfcReinforcingMesh",
@@ -82,6 +82,7 @@ BUILTIN_CATEGORY_MAP: dict[str, str] = {
     "OST_PipeAccessory":                    "IfcPipeSegment",
     "OST_FlexPipeCurves":                   "IfcPipeSegment",
     "OST_PlumbingFixtures":                 "IfcSanitaryTerminal",
+    "OST_PlumbingEquipment":                "IfcSanitaryTerminal",
     "OST_Sprinklers":                       "IfcFireSuppressionTerminal",
 
     # MEP - Electrical
@@ -119,44 +120,22 @@ 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",
+# --- OST categories to skip entirely (analytical / energy / separation lines) ---
+SKIP_CATEGORIES: set[str] = {
+    "OST_MEPLoadAreaSeparationLines",
+    "OST_EnergyAnalysisZones",
+    "OST_EnergyAnalysisSurface",
+    "OST_SolarShading",
+    "OST_MEPAnalyticalPipeSegments",
+    "OST_MEPAnalyticalDuctSegments",
+    "OST_MEPAnalyticalSpaces",
+    "OST_ElectricalConduitAnalyticalLines",
+    "OST_MEPLoadBoundaryLines",
+    "OST_FlowTerminalSeparationLines",
 }
 
-# --- Display category name → IFC class (tertiary fallback) ---
+
+# --- Display category name → IFC class (secondary fallback) ---
 CATEGORY_MAP: dict[str, str] = {
     "Walls":                        "IfcWall",
     "Floors":                       "IfcSlab",
@@ -184,10 +163,13 @@ CATEGORY_MAP: dict[str, str] = {
     "Furniture Systems":            "IfcFurnishingElement",
     "Casework":                     "IfcFurnishingElement",
     "Plumbing Fixtures":            "IfcSanitaryTerminal",
+    "Plumbing Equipment":           "IfcSanitaryTerminal",
     "Electrical Fixtures":          "IfcElectricAppliance",
     "Lighting Fixtures":            "IfcLightFixture",
     "Mechanical Equipment":         "IfcUnitaryEquipment",
     "Electrical Equipment":         "IfcElectricDistributionBoard",
+    "Structural Rebar":             "IfcReinforcingBar",
+    "Structural Connections":       "IfcMechanicalFastener",
     "Structural Foundations":       "IfcFooting",
     "Foundation Slabs":             "IfcSlab",
     "Topography":                   "IfcGeographicElement",
@@ -235,11 +217,6 @@ 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()
@@ -249,16 +226,15 @@ _CATEGORY_MAP_LOWER: list[tuple[str, str]] = [
 _classify_cache: dict[tuple, str] = {}
 
 
-def classify(obj, category_name: str = "") -> str:
+def classify(obj, category_name: str = "") -> str | None:
     """
     Determine the IFC class for a Speckle object.
 
     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:
@@ -269,22 +245,17 @@ def classify(obj, category_name: str = "") -> str:
     return result
 
 
-def _classify_impl(obj, category_name: str) -> str:
-    # 1. builtInCategory — most reliable, direct Revit enum
+def _classify_impl(obj, category_name: str) -> str | None:
+    # 0. Skip analytical / energy / separation-line categories
     bic = _get_builtin_category(obj)
+    if bic and bic in SKIP_CATEGORIES:
+        return None
+
+    # 1. builtInCategory — most reliable, direct Revit enum
     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 +264,7 @@ 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

@@ -53,6 +53,10 @@ COMMON_PSET: dict[str, str] = {
     "IfcOpeningElement":            "Pset_OpeningElementCommon",
     "IfcPlate":                     "Pset_PlateCommon",
     "IfcGeographicElement":         "Pset_SiteCommon",
+    "IfcPipeFitting":               "Pset_PipeFittingTypeCommon",
+    "IfcSanitaryTerminal":          "Pset_SanitaryTerminalTypeCommon",
+    "IfcReinforcingBar":            "Pset_ReinforcingBarBendingsBECCommon",
+    "IfcMechanicalFastener":        "Pset_MechanicalFastenerTypeCommon",
 }
 
 # ---------------------------------------------------------------------------
@@ -424,9 +428,104 @@ def write_common_pset(ifc, element, obj: Base, ifc_class: str, category_name: st
             except Exception:
                 pass
 
+    # IfcSpace-specific: set Name, LongName, Category, and BaseQuantities
+    if ifc_class == "IfcSpace":
+        _write_space_properties(ifc, element, obj, ifc_props)
+
     _write_pset(ifc, element, pset_name, ifc_props)
 
 
+def _write_space_properties(ifc, element, obj: Base, ifc_props: list):
+    """
+    Set IfcSpace attributes and BaseQuantities from Revit Room parameters.
+
+    Uses internalDefinitionName to find values:
+      ROOM_NUMBER  → IfcSpace.Name + Pset_SpaceCommon.Reference
+      ROOM_NAME    → IfcSpace.LongName
+      Occupant     → Pset_SpaceCommon.Category
+      ROOM_AREA    → Qto_SpaceBaseQuantities.NetFloorArea
+      ROOM_VOLUME  → Qto_SpaceBaseQuantities.NetVolume
+    """
+    props = _get_props_dict(obj)
+    params = _safe_get(props, "Parameters", {})
+    inst_params = _safe_get(params, "Instance Parameters", {})
+
+    # --- Room Number → IfcSpace.Name + Pset_SpaceCommon.Reference ---
+    room_number = _param_value(inst_params, "ROOM_NUMBER")
+    if room_number:
+        room_number = str(room_number).strip()
+        element.Name = room_number
+        # Replace any existing Reference in ifc_props
+        ifc_props[:] = [p for p in ifc_props if p.Name != "Reference"]
+        p = _make_prop(ifc, "Reference", "IfcIdentifier", room_number)
+        if p:
+            ifc_props.append(p)
+        # Also add as explicit RoomNumber in the pset
+        p = _make_prop(ifc, "RoomNumber", "IfcLabel", room_number)
+        if p:
+            ifc_props.append(p)
+
+    # --- Room Name → IfcSpace.LongName + Pset_SpaceCommon.RoomName ---
+    room_name = _param_value(inst_params, "ROOM_NAME")
+    if not room_name:
+        # Fallback to the Speckle object's own name
+        room_name = getattr(obj, "name", None)
+    if room_name:
+        room_name = str(room_name).strip()
+        try:
+            element.LongName = room_name
+        except AttributeError:
+            pass
+        p = _make_prop(ifc, "RoomName", "IfcLabel", room_name)
+        if p:
+            ifc_props.append(p)
+
+    # --- Occupant → Pset_SpaceCommon.Category ---
+    occupant = _param_value(inst_params, "Occupant")
+    if occupant:
+        p = _make_prop(ifc, "Category", "IfcLabel", str(occupant).strip())
+        if p:
+            ifc_props.append(p)
+
+    # --- Area & Volume → Qto_SpaceBaseQuantities ---
+    quantities = []
+
+    area_val = _param_value(inst_params, "ROOM_AREA")
+    if area_val is not None:
+        try:
+            q = ifc.create_entity(
+                "IfcQuantityArea",
+                Name="NetFloorArea",
+                AreaValue=float(area_val),
+            )
+            quantities.append(q)
+        except Exception:
+            pass
+
+    volume_val = _param_value(inst_params, "ROOM_VOLUME")
+    if volume_val is not None:
+        try:
+            q = ifc.create_entity(
+                "IfcQuantityVolume",
+                Name="NetVolume",
+                VolumeValue=float(volume_val),
+            )
+            quantities.append(q)
+        except Exception:
+            pass
+
+    if quantities:
+        try:
+            qto = ifcopenshell.api.run(
+                "pset.add_qto", ifc,
+                product=element,
+                name="Qto_SpaceBaseQuantities",
+            )
+            qto.Quantities = quantities
+        except Exception as e:
+            print(f"  ⚠️  Qto_SpaceBaseQuantities: {e}")
+
+
 # ---------------------------------------------------------------------------
 # Pset_EnvironmentalImpactIndicators (always written, Reference = TypeName)
 # ---------------------------------------------------------------------------
@@ -549,7 +648,7 @@ 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)
@@ -616,7 +715,7 @@ 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,
@@ -628,6 +727,107 @@ 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",
+    "IfcPipeFitting":               "Qto_PipeFittingBaseQuantities",
+    "IfcSanitaryTerminal":          "Qto_SanitaryTerminalBaseQuantities",
+    "IfcReinforcingBar":            "Qto_ReinforcingElementBaseQuantities",
+    "IfcMechanicalFastener":        "Qto_MechanicalFastenerBaseQuantities",
+}
+
+# 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:
@@ -636,10 +836,12 @@ 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)