IFC Syntax : Data Types

This skill answers one concrete question : what can the value of an IFC attribute or property hold, and how is that value typed in a file? It covers IFC's own resource- layer value-type system : the named defined types (IfcLengthMeasure, IfcLabel, IfcBoolean, ...) and the SELECT unions that group them.

Applies to IFC2x3, IFC4, and IFC4.3. Member lists differ by version : see the Version Differences section.