IFCZIP is a compressed form of IFCXML or IFC file. IFCZIP file format is used by various CAD software for archiving purposes (i.e. to reduce file size). Compression process is usually performed during creation of project archive database.

Although IFCZIP files can save significant disk space, CAD designers seldom utilize this format and therefore IFCZIP files are rarely seen in project folders. Designers prefer to leave files in  formats in which they were created by given software application.