Industry Foundation Classes

The Industry Foundation Classes (IFC) data model is intended to describe architectural, building and construction industry data. The Industry Foundation Classes (IFC) data model is intended to describe architectural, building and construction industry data. It is a platform neutral, open file format specification that is not controlled by a single vendor or group of vendors. It is an object-based file format with a data model developed by buildingSMART (formerly the International Alliance for Interoperability, IAI) to facilitate interoperability in the architecture, engineering and construction (AEC) industry, and is a commonly used collaboration format in Building information modeling (BIM) based projects. The IFC model specification is open and available. It is registered by ISO and is an official International Standard ISO 16739-1:2018. Because of its focus on ease of interoperability between software platforms, the Danish government has made the use of IFC format(s) compulsory for publicly aided building projects. Also, the Finnish state-owned facility management company Senate Properties demands use of IFC compatible software and BIM in all their projects. Also the Norwegian Government, Health and Defense client organisations require use of IFC BIM in all projects as well as many municipalities, private clients, contractors and designers have integrated IFC BIM in their business. The IFC initiative began in 1994, when Autodesk formed an industry consortium to advise the company on the development of a set of C++ classes that could support integrated application development. Twelve US companies joined the consortium. These companies included AT&T, HOK Architects, Honeywell, Carrier, Tishman and Butler Manufacturing. Initially named the Industry Alliance for Interoperability, the Alliance opened membership to all interested parties in September, 1995 and changed its name in 1997 to the International Alliance for Interoperability. The new Alliance was reconstituted as a non-profit industry-led organization, with the goal of publishing the Industry Foundation Class (IFC) as a neutral AEC product model responding to the AEC building lifecycle. A further name change occurred in 2005, and the IFC specification is now developed and maintained by buildingSMART. IFC defines multiple file formats that may be used, supporting various encodings of the same underlying data. IFC defines an EXPRESS based entity-relationship model consisting of several hundred entities organized into an object-based inheritance hierarchy. Examples of entities include building elements such as IfcWall, geometry such as IfcExtrudedAreaSolid, and basic constructs such as IfcCartesianPoint. At the most abstract level, IFC divides all entities into rooted and non-rooted entities. Rooted entities derive from IfcRoot and have a concept of identity (having a GUID), along with attributes for name, description, and revision control. Non-rooted entities do not have identity and instances only exist if referenced from a rooted instance directly or indirectly. IfcRoot is subdivided into three abstract concepts: object definitions, relationships, and property sets: