An IFC file turns up in your inbox from the architect or the constructeur, and most people do the same thing with it: open it, spin the model, close it again. A file you can look at but not touch. That is a shame, because IFC is the one part of BIM that was built to be opened by anyone, in any tool, for the whole life of the building. Here is what it actually is.
IFC stands for Industry Foundation Classes. Three words that sound like a committee named them, because a committee did. What they describe is simpler than the name.
A standard, not a file type someone owns
Most file types belong to the company that made the program. Open one in a rival tool and you get a mess, or nothing. IFC was built the other way around. It is an open, international standard, looked after by a neutral body called buildingSMART, and published as ISO 16739. The current version, IFC 4.3, was ratified by ISO in 2024 as ISO 16739-1:2024.
That word "open" is the whole point. A constructeur can model in one program, the architect in another, the installateur in a third, and all three export to IFC. Put those files together and they line up in one scene, because they speak a shared language. You are not tied to one company's software for the ten years you have to keep the records.
A file of objects, not lines
A drawing is lines. An IFC file is objects. Each wall in the model is a thing that knows it is a wall: its type, its size, what it is made of, where it sits and what it connects to. buildingSMART describes the schema as carrying three things for every element. Its identity, including a machine-readable unique code. Its characteristics, such as material or thermal properties. And its relationships, such as where it sits and what it is joined to.
That unique code matters more than it sounds. Every element in an IFC model has its own identifier, stable across the file. It is the hook. Pin a snag, attach a photo, run a compliance rule, and all of it can hang off that one element instead of a vague note on a drawing. A finding stops being "crack near the second-floor stairwell" and becomes a place on a specific object anyone can walk back to.
It is not just for buildings any more
For years IFC described buildings and little else. IFC 4.3, the version now in ISO, widened it to civil infrastructure: roads, railways, bridges, ports and waterways, with proper georeferencing so a model knows where on earth it sits. The same open format now reaches from a house to a motorway, which is why openBIM has started to carry infrastructure too, not just buildings.
What IFC is not
IFC is not magic, and it is not a guarantee of quality. An IFC export can be a geometric shell with almost no data behind it: every wall present, nothing to ask it.
An empty model looks fine and answers nothing
The value of an IFC model is in its properties, not its shape. A model exported without its property sets will look correct on screen and tell you almost nothing when you ask it a question. Good data in is the whole job.
And IFC is not the program you drew in. It is the neutral copy you hand on, so the next tool, and the next decade, can still read it.
Why it matters on site, and to the Wkb
Here is where it reaches the boots on the ground. When a building is real data and not a flat picture, a defect has somewhere exact to live, quantities come off the model, and a check can be run against the elements themselves.
Proof is easier when it sits on the model
In the Netherlands the Wkb has asked contractors to prove their work at gereedmelding since 2024. Proof is far easier when each finding, photo and certificate sits on the element it concerns, in an open format, than when it lives in a folder of loose files nobody can search.
Where we come in
That is what BimDossier is built on. It reads the IFC you are sent, loads federated models from every discipline into one viewer, and lets you pin a finding to an element by its own identifier, with a photo and an owner. The compliance engine runs its rule packs against the same IFC data. The format is open and European, the same from Rotterdam to anywhere the standard reaches. What you build on top of it, the snags, the certificates, the Wkb dossier, still sits on your model.