Convert SLDASM to IFC in your application
3D InterOp is a CAD interoperability SDK that lets your software read SLDASM files and write IFC, writing the exact geometry into a format that can also hold facets.
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 SOLIDWORKS assembly · Writes IFC
- Exact geometry → mixed-geometry format
- C++ / C# APIs
SLDASM to IFC at a glance
SOLIDWORKS assembly stores exact geometry; IFC can hold exact solids and facets. What ends up in the IFC file depends on what the IFC writer writes, as detailed below.
| SOLIDWORKS assembly (source) | IFC (target) | |
|---|---|---|
| Full name | SOLIDWORKS Assembly | Industry Foundation Classes |
| Standard / owner | Dassault Systèmes SOLIDWORKS | buildingSMART, ISO 16739 |
| File extensions | .sldasm | .ifc, .ifczip |
| Geometry | Exact B-Rep (in the referenced parts) | Exact B-Rep and tessellated geometry |
| Assemblies / structure | Yes | Yes: spatial and element hierarchy |
| PMI | Semantic (DimXpert) and graphical, SOLIDWORKS 2014 and later | Not part of the IFC schema |
| 3D InterOp support | Read only | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from SOLIDWORKS assembly to IFC.
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Preserved
Exact geometryExact B-Rep read from SLDASM is written to IFC as exact geometry.
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Preserved
Product structureThe SLDASM product structure is written to IFC.
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Not carried
PMIIFC has no PMI, so the PMI read from SLDASM isn’t written. Keep STEP AP242 as an output when PMI matters.
Why software vendors add SLDASM 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.
- SLDASM has no BIM semantics: check which IFC class your application assigns to each object.
- Supported SLDASM input: SOLIDWORKS 98 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 SLDASM (.sldasm) file?
An SLDASM file is a SOLIDWORKS assembly. It defines how parts and sub-assemblies fit together and references the SLDPRT files that hold their geometry.
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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 SLDASM is written to IFC.
IFC has no PMI, so the PMI read from SLDASM isn’t written. When PMI matters, offer STEP AP242 as an output.
Yes. 3D InterOp reads the SLDASM 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.
SLDASM has no BIM semantics, so your application decides which IFC class each object is written as.
Yes. If your application uses Parasolid, a Parasolid-based SOLIDWORKS reader is available.
Semantic PMI from SOLIDWORKS 2014 to 2026, and graphical PMI from SOLIDWORKS 2014 onwards.
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Building software that needs to convert SLDASM to IFC?
3D InterOp is an SDK that lets your application read SOLIDWORKS assembly and write IFC alongside 30+ CAD and BIM formats.