“Can you send it as an IFC?” is a sentence you hear constantly on BIM projects — yet surprisingly few people can explain what IFC actually is. This article breaks it down in plain language: what IFC is, why it matters, and the things people commonly get wrong.
- IFC is the vendor-neutral common file format for building BIM (an ISO standard)
- It carries not just geometry but properties and relationships — meaningful data
- IFC2x3 is the de-facto standard, IFC4 the successor, IFC4.3 adds infrastructure
- Conversion is never perfect, so export settings and version are what matter
IFC is the “common language” of buildings
IFC (Industry Foundation Classes) is an open, vendor-neutral data format for BIM in the architecture, engineering and construction (AEC) industry. It’s maintained by buildingSMART International, a non-profit standards body — no single software company owns it. It’s also an international standard, ISO 16739.
The key idea is independence from any one tool. Revit, ArchiCAD, Vectorworks, Tekla — every BIM application has its own native save format (.rvt, .pln, and so on), and those generally can’t be opened in a competitor’s software. IFC sits in the middle as a shared language. A designer models in ArchiCAD; a contractor opens that model in a different package to review it. IFC is what makes that handoff possible.
IFC carries more than just shapes
Many people assume IFC is “a container for 3D geometry.” That’s only half right. IFC actually carries three kinds of information:
Geometry
The 3D shape of each element — walls, slabs, columns.
Properties
Data per element — material, fire rating, manufacturer, product code.
Relationships
How elements connect — "this door opens in this wall."
In other words, IFC isn’t a bag of polygons; it’s a building described as meaningful data. A wall is recognised as a wall, a door as a door. That semantic layer is the decisive difference between IFC and pure visualisation formats like glTF or OBJ.
Why IFC is necessary
A construction project involves architects, structural and MEP engineers, the main contractor, specialist trades, the owner — all using different software. If everyone had to buy the same application just to exchange data, the cost and friction would be enormous.
With IFC, each party keeps the tools they know and hands models over in a shared format. This philosophy of vendor-neutral collaboration is called openBIM, and IFC is its backbone.
The versions: IFC2x3 / IFC4 / IFC4.3
IFC comes in generations. Three matter in practice:
The de-facto standard
The most widely used version for years, still specified on many projects. The safe choice when compatibility comes first.
The successor
Improved geometry representation and richer properties. Tool support has grown but hasn't fully overtaken IFC2x3 in the field.
Infrastructure-ready
Extends coverage to bridges, roads, rail and tunnels — widening openBIM beyond buildings to civil works.
Always confirm which version of IFC you’re exchanging. If the sender and receiver assume different versions, you can silently lose elements or properties.
Common misconceptions
"IFC moves everything across perfectly." Not true. IFC is a shared format, but it doesn't preserve every vendor-specific feature or parametric editing history. What ends up in the file depends heavily on the export settings — most "I sent an IFC but the properties were empty" incidents come down to how the model was exported.
"IFC is read-only." Also not true. IFC isn't a view-only format. There are tools that let you inspect and edit element properties, raise issues, and work with the geometry.
Summary
- IFC is the open, vendor-neutral file format for building BIM (an ISO standard).
- It carries not just geometry but properties and relationships — a building as meaningful data.
- IFC2x3 is today’s safe default, IFC4 is the successor, IFC4.3 adds infrastructure.
- Conversion is never perfect, so export settings and version are what matter in practice.
Understanding IFC properly removes a lot of the pain from data handoffs. A good first step is simply to open one of your own IFC files and look at the elements and properties inside.