Convert RFA to IFC in your application
3D InterOp is a CAD interoperability SDK that lets your software read RFA files and write IFC, mapping geometry and structure from one model format to the other.
Spatial does not offer an online converter or a desktop conversion app. 3D InterOp is a component that software vendors embed in their own products.
- Reads Revit family · Writes IFC
- Mixed geometry → mixed geometry
- C++ / C# APIs
RFA to IFC at a glance
Both formats can hold exact solids and faceted geometry. The translation is about how geometry, structure and properties map from Revit family to IFC.
| Revit family (source) | IFC (target) | |
|---|---|---|
| Full name | Revit family | Industry Foundation Classes |
| Standard / owner | Autodesk | buildingSMART, ISO 16739 |
| File extensions | .rfa | .ifc, .ifczip |
| Geometry | B-Rep and mesh (read); mesh (written by 3D InterOp) | Exact B-Rep and tessellated geometry |
| Assemblies / structure | Nested families; assembly structure written by 3D InterOp | Yes: spatial and element hierarchy |
| 3D InterOp support | Read and write | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from Revit family to IFC.
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Preserved
Exact geometryExact B-Rep read from RFA is written to IFC as exact geometry.
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Preserved
Product structureThe RFA product structure is written to IFC.
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Changes
Faceted partsParts the RFA file stores only as facets are written as facets.
Why software vendors add RFA to IFC conversion
Open BIM deliverables
Many projects specify IFC deliverables. Writing it lets your users meet those requirements from your software.
Coordination and clash detection
Coordination tools gather models from every discipline in IFC. Your users can contribute without a round trip through another tool.
Facility and asset data
Owners and operators often receive building data as IFC for asset management after handover.
Things to check before you ship
- Written IFC versions: IFC2x3 to IFC4x3 ADD2 (.ifc).
- Exact B-Rep needs IFC4 or later; IFC2x3 files only get tessellation.
- Supported RFA input: Revit 2015 to 2026.
- Validate a sample of translated files in the target system your users actually work with.
Working with Spatial was a real milestone for us: Thanks to the powerful 3DInterOp library, we were able to successfully bring our complex CAD-based solutions to the cloud while remaining flexible to meet individual customer requirements. For us, Spatial is not just a technology partner, but a true enabler of our product strategy.
Dr. Arno Michelis, Founder, Simus Systems
Read the Case StudyAbout the formats
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Source format
What is an RFA (.rfa) file?
An RFA file is a Revit family: a reusable component such as a door, a window or a piece of equipment, with its geometry, types and parameters, loaded into Revit projects.
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Target format
What is an IFC (.ifc) file?
IFC is the open, vendor-neutral standard for exchanging building information models, maintained by buildingSMART and published as ISO 16739. It carries building elements with their geometry, properties and relationships.
Frequently asked questions
The exact B-Rep that 3D InterOp reads from RFA is written to IFC; parts stored only as facets stay faceted.
Yes. 3D InterOp reads the RFA product structure and writes it to IFC.
Write IFC4 or later to keep exact B-Rep: IFC2x3 files only get tessellation. 3D InterOp writes IFC2x3 to IFC4x3 ADD2.
3D InterOp reads Revit 2015 to 2026.
3D InterOp writes IFC2x3 to IFC4x3 ADD2 (.ifc).
Yes. 3D InterOp reads and writes both formats, so IFC to RFA is supported too.
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Building software that needs to convert RFA to IFC?
3D InterOp is an SDK that lets your application read Revit family and write IFC alongside 30+ CAD and BIM formats.