Coulter BIM Information Management

The Industry Foundation Classes (IFC) standard has officially taken another step forward, with ISO publishing a new Compatibility Policy for ISO 16739-1, the international standard behind IFC. This policy aims to give the whole industry a clearer, more predictable roadmap for how IFC will evolve in future releases, how breaking changes will be handled, and how the schema will remain stable for long-life asset data.

It’s a quietly significant update. IFC is the backbone of openBIM, and this new policy makes the standard more transparent, better governed, and easier to trust for long-term projects. But as always, there’s a gap between what the standard promises and what everyday software can actually deliver. And nowhere is that more obvious than Revit.

What ISO 16739 Is (and isn’t)

ISO 16739-1 is the international standard that defines the IFC data schema, geometry rules, object classes, relationships, spatial structure (project > site > building > storey > space). It is essentially the “source code” of IFC.

But it is not a workflow guide and does not mention Revit, ArchiCAD, Tekla, Bentley, or any specific software. ISO standards cannot reference proprietary tools. So ISO will never tell you how to export IFC from Revit, how Revit should map categories to IFC entities, or how software should implement IFC4.3.

That’s where the real-world problem starts.

The New Compatibility Policy: What It Means

The new compatibility policy published by ISO/TC 59/SC 13 and buildingSMART introduces clearer rules for future IFC releases. It defines what counts as a breaking change, how deprecated items must be handled, how extensions should be structured, and what compatibility guarantees software vendors can rely on when implementing new versions.

This is important because IFC is expanding rapidly, especially with IFC4.3 for infrastructure (roads, rail, bridges). Without a robust compatibility framework, software vendors struggle to keep up and asset owners worry about long-term data preservation. The policy brings IFC closer to behaving like a modern, stable digital platform.

The Reality: Revit Is Still Stuck on IFC4

Despite IFC advancing, Revit can currently export only IFC4, not IFC4.3. That means no support for alignment-based entities, no infra modelling compatibility, and no ability to produce IFC4.3 deliverables that many countries and infrastructure clients are now adopting.

Revit’s IFC exporter is open-source and jointly developed by Autodesk and the openBIM community, but it consistently lags behind buildingSMART’s releases. For buildings, IFC4 is workable, but for mixed building–infrastructure projects, it creates a bottleneck.

And COBie? Still IFC2x3 MVD

The situation is even more limiting when it comes to COBie (and I am a huge fan of COBie). Revit’s COBie workflows (including Autodesk Interoperability Tools and legacy extensions) still rely entirely on IFC2x3-based COBie MVD.

This means COBie deliverables depend on a schema from 2006. While IFC pushes forward, one of the most common structured-data deliverables in UK and Irish projects is anchored to IFC2x3. There is no native IFC4-based COBie export in Revit, and the industry is still waiting for COBie to properly align with modern IFC releases.

This creates a disconnect: IFC evolves, but COBie workflow tools don’t.

Why This Matters for BIM Information Managers

BIM Information Managers are responsible for planning, validating and coordinating IFC exports, COBie deliverables, classification mapping, and ISO 19650-compliant CDE workflows. But the technical limitations of software tools constrain what can be delivered.

If a client specifies IFC4.3, Revit cannot provide it.

If a client wants COBie aligned with IFC4, Revit cannot deliver it.

If infrastructure teams move to IFC4.3, Revit stays behind.

To keep projects running, IM leads are forced to specify a mixture of:

• IFC4 for model exchange
• IFC2x3 for COBie
• Custom property sets and mapping files to fill gaps

It works, but it creates complexity and raises the risk of inconsistent data across the supply chain.

My Perspective: Software Vendors Must Step Up

Standards bodies are doing their job. ISO is improving governance. buildingSMART is expanding IFC into new domains and formalising IDS for structured data exchange. IFC4.3 is becoming globally recognised.

But major software vendors, especially Autodesk, are not keeping pace.

Revit is still the dominant tool in the UK and Ireland. When it lags behind the IFC schema, the whole industry lags with it. And without IFC4.3 support, building–infrastructure workflows remain broken.

If BIM is truly about information, not geometry, then software vendors need to prioritise openBIM implementation with the same seriousness as standards organisations.

Conclusion

ISO 16739-1’s new Compatibility Policy is a positive and long-needed improvement to the IFC ecosystem. It strengthens the stability, transparency and predictability of openBIM standards. But until mainstream authoring tools like Revit support new IFC versions and updated COBie workflows, BIM Information Managers will continue to wrestle with outdated export limitations while the standards move ahead.

The message is simple: the standards are evolving. The tools now need to catch up.