IFC Properties Don't Belong in Revit with Thomas Zwielehner | openBIMvoice 05

In the fifth episode of openBIMvoice, I talk with Thomas Zwielehner, an architect who now manages BIM workflows on large railway infrastructure projects in Germany. On his current project there are more than 500 IFC files. His team asked one question that changed everything: why are designers the bottleneck for data that has nothing to do with their design? Most projects never ask which properties actually require a modeller to enter them. Thomas asked. The answer was 80% do not. That single question changed how his entire team works. What we discuss: From Architecture to Infrastructure. Thomas explains what changed when he moved from small building projects to railway at scale. With 500 or more IFC files on a single project, every inefficiency multiplies fast. The 80% Discovery. How they audited every property requirement and found that most properties had no reason to live in Revit or Civil 3D. This single finding changed how the whole team thinks about BIM data. Building the Database. What they actually built: a browser-based system where anyone on the project can enter data directly, with live IDS-compatible validation at the point of entry. No more waiting weeks for a quality report. Geometry and Data Separated. Why they deliberately keep the 3D geometry and the property data in separate systems, and how they use IFC OpenShell to merge them back into a compliant IFC file at handover. AI as an Amplifier. Thomas's view on what AI tools actually do in a workflow like this. Good domain knowledge gets multiplied. Bad domain knowledge gets multiplied too. Find me on LinkedIn: https://www.linkedin.com/in/petruconduraru/ Questions: [email protected]