Free online IFC to BREP converter

IFC models often need conversion when a CAD or geometry kernel accepts boundary-representation solids but cannot read BIM exchange data. Converting to BREP produces editable geometric topology, but it does not preserve IFC object classifications, properties, relationships, or most BIM metadata.

What the IFC format is

IFC, usually stored as .ifc, is an open BIM exchange format defined by buildingSMART. It stores building elements such as walls, slabs, doors, pipes, and equipment together with geometry, materials, classifications, quantities, spatial hierarchy, and relationships.

Architectural, structural, and MEP applications create IFC files during model exchange and coordination. Common sources include Autodesk Revit, Archicad, Tekla Structures, Bentley applications, Allplan, and Vectorworks. IFC is normally encountered when receiving a coordination model from another discipline or when importing a project into a viewer, clash-detection system, or BIM platform.

What the BREP format is

BREP, or boundary representation, describes a solid or surface through its vertices, edges, wires, faces, shells, and geometric surfaces. Files commonly use .brep or .brp; the exact syntax depends on the CAD kernel, with Open CASCADE BREP being a common implementation.

BREP is useful for CAD editing, Boolean operations, validation, machining preparation, and geometry exchange with applications based on Open CASCADE or similar kernels. It retains explicit topological geometry rather than IFC’s building-object semantics. A BREP export is therefore suitable for shape processing, not for transferring a complete BIM model.

How to actually convert IFC to BREP

Using FreeCAD

1. Install FreeCAD with its BIM/IFC support and open the .ifc file through File → Open. If the IFC importer is not available, enable the BIM workbench or install a FreeCAD package that includes IfcOpenShell.
2. Wait for the model to finish importing, then inspect the tree and hide unnecessary objects. Exporting every IFC object can create hundreds or thousands of BREP files.
3. Select the required solid or group of solids in the model tree. Use File → Export and choose BREP if it is offered by the installed FreeCAD version, then save as model.brep.
4. If the export dialog does not list BREP, use the FreeCAD Python console after importing the IFC. For a selected object with a valid shape, run:

obj = Gui.Selection.getSelection()[0]
obj.Shape.exportBrep("/path/to/model.brep")

For multiple objects, export each valid shape to a separate file or create a compound first. A compound keeps several disconnected parts in one BREP file but does not turn them into a single watertight solid.

Using an online conversion service

You can also upload the IFC file to 101convert.com, select BREP as the output format when available, and download the converted file without installing software. Check the service’s file-size, privacy, and geometry-support limits before uploading a project containing confidential building information.

Quality and compatibility limitations

• IFC metadata is discarded: names, GUIDs, property sets, materials, quantities, spatial containment, and relationships generally do not exist in BREP.
• Not every IFC entity becomes a solid: annotations, spaces, grids, point data, meshes, proxy objects, and some swept or advanced representations may be skipped or exported as surfaces.
• Openings and Boolean results can change: an importer may resolve wall openings into final faces, retain them as separate features, or fail when the source geometry is invalid.
• Inspect units: BREP files often do not carry reliable project-unit metadata. Confirm the model scale after import; IFC projects commonly use metres or millimetres.
• Validate topology: run the target CAD system’s geometry check for gaps, self-intersections, reversed faces, non-manifold edges, and non-watertight shells. A visually correct model can still fail Boolean or machining operations.
• Choose the export scope deliberately: export individual parts when downstream editing is required; export a compound when the recipient only needs the complete geometric assembly.