What is the difference between IFC and BCF?
IFC is the open file format that describes the building model itself — its elements and their properties. BCF (BIM Collaboration Format) is the companion format for the issues and comments raised against that model, such as clashes and design queries, each linked to specific elements.
IFC (Industry Foundation Classes) and BCF (BIM Collaboration Format) are both open buildingSMART standards, but they carry different things:
- IFC is the model. It describes the geometry and data of every element — walls, beams, ducts, equipment — and gives each a stable GlobalID. It is the vendor-neutral way to exchange a BIM model between tools.
- BCF is the conversation about the model. It is a lightweight format for coordination issues — a clash, an RFI, a design check — where each topic references the IFC elements it concerns, plus a viewpoint, status and comments. It lets teams exchange issues without sending the whole model back and forth.
They work together: BCF points at IFC elements by their GlobalID. Bildstak reads both, so a BCF issue and the IFC element it targets are joined automatically — and from there linked on to the matching RFI, cost line or schedule activity. That is what lets you click an element and see every issue raised against it.
Updated 2026-06-19