Export FreeCAD Architectural Models to IFC

Exporting architectural models from FreeCAD to Industry Foundation Classes (IFC) format allows Building Information Modeling (BIM) data to be shared across various industry-standard CAD and BIM platforms. This process requires organizing your model with standard architectural containers, ensuring the underlying conversion engine is enabled, and choosing the proper IFC schema during export. Below is the direct, step-by-step process to prepare, configure, and export your architectural models cleanly into IFC.

1. Ensure IfcOpenShell Is Installed

FreeCAD uses an open-source library called IfcOpenShell to read and write IFC files.

  1. Open FreeCAD and switch to the BIM Workbench (or Arch Workbench in older versions).
  2. Go to Edit > Preferences > BIM > IFC.
  3. Check the status of IfcOpenShell. If it is missing, install it via the FreeCAD Addon Manager (Tools > Addon Manager) or install the python3-ifcopenshell package matching your Python environment.

2. Organize the Model Hierarchy

For an IFC export to be recognized correctly by other BIM software, objects must be organized logically within a spatial hierarchy:

  1. Project: Create a BIM Project container.
  2. Site: Add a Site object inside the Project.
  3. Building: Add a Building container inside the Site.
  4. Building Storey (Level): Create Storeys (e.g., Level 1, Level 2) within the Building.
  5. Architectural Elements: Place your BIM elements (walls, doors, windows, slabs, columns) inside their respective Building Storey containers.

Ensure each element has appropriate properties assigned (such as dimensions, materials, and IFC roles like IfcWall or IfcWindow).

3. Configure IFC Export Preferences

Before exporting, set your target IFC version:

  1. Navigate to Edit > Preferences > BIM > IFC.
  2. Select your desired Default IFC export version:
    • IFC2x3: Best for compatibility with older software or legacy workflows.
    • IFC4: Better support for complex geometry and newer BIM standards.
  3. Ensure Export full FreeCAD parametric model is disabled unless the receiving software specifically supports FreeCAD-based parametric objects. Standard geometric representation ensures broader compatibility.

4. Export the Model

Once your model is structured and settings are confirmed:

  1. In the Tree View, select the top-level Project or Building container (or select all specific objects you want to include).
  2. Go to File > Export.
  3. In the export dialog, choose **Industry Foundation Classes (*.ifc)** from the file type dropdown menu.
  4. Name your file and click Save.

5. Verify the Export

Always open the exported .ifc file in an external, dedicated IFC viewer (such as BIMvision, Solibri, or Blender with Bonsai BIM) to confirm that geometries, spatial trees, and assigned properties transferred accurately.