IFC Data Exchange

Moving building model data between different BIM tools using the open IFC format.

Quick Answer

IFC data exchange is the practice of sharing building model information between different BIM applications using the Industry Foundation Classes format, an open standard maintained by buildingSMART and published as ISO 16739-1. An IFC file carries geometry, object types, properties, and relationships so tools from different vendors can read the same model.

The Full Picture

Every BIM authoring tool stores models in its own native format. IFC is a neutral format that sits between them. A designer exports a model to IFC from the authoring tool, and a contractor, analyst, or owner opens it in a different application. The file describes building elements such as walls, doors, and spaces, their properties, and how they relate to one another.

IFC is developed by buildingSMART International and standardized by ISO as ISO 16739-1. Versions are numbered, and different releases are common in practice, so the exporting and importing tools should support a compatible version. IFC 4.3 extended the schema to cover infrastructure assets such as roads and bridges as well as buildings.

Because models are large and purposes vary, exchanges are usually scoped using Model View Definitions, which specify the subset of IFC needed for a given purpose, such as design coordination. Teams also define what properties must be present, since IFC can carry far more than any one export includes.

IFC exchange is lossy in practice when export settings are poor or the importing tool supports only part of the schema. Good projects agree on the IFC version and view, test an exchange early, and validate files before relying on them for downstream work such as coordination, quantity extraction, or handover.

Real Examples

→Design coordination: Each discipline exports an IFC model, and the BIM coordinator opens all of them in a neutral viewer to check for conflicts.

→Owner handover: An owner requires an IFC export at project completion so asset data can be loaded into its own facilities systems independent of the design software.

→Quantity extraction: An estimator imports an IFC model into a takeoff tool and extracts areas and counts, checking the numbers against the 2D drawings.

Common Misconceptions

People assume: Exporting to IFC always preserves everything in the native model.

Actually: IFC exports map native objects to the IFC schema, and settings determine what is included. Properties, geometry details, or custom content can be lost or simplified.

People assume: All IFC versions are interchangeable.

Actually: Different versions, such as IFC2x3 and IFC4, have different schemas, and tools support them to varying degrees. Teams should agree on a version and test the exchange.

Frequently Asked Questions

What does IFC stand for?

IFC stands for Industry Foundation Classes. It is an open data schema for describing buildings and infrastructure, maintained by buildingSMART International and published as ISO 16739-1.

What is a Model View Definition?

A Model View Definition (MVD) specifies which part of the IFC schema is used for a particular exchange purpose, such as design coordination, so exporters and importers agree on what data to include.

What file extensions does IFC use?

The most common is .ifc, which uses a text-based encoding. IFC data can also be stored in other encodings such as XML or compressed packages (.ifczip).

Is IFC the same as openBIM?

No. IFC is one standard within the broader openBIM approach, which also includes BCF for issues, IDS for information requirements, and the bSDD dictionary.