Universal CAD for the Building Industry

Peter Muigg

Object-oriented (OO) technology is gradually changing the shape of CAD, making these systems smarter and more user-friendly. Users of OO CAD can work with real-world objects that "know" how to interact with other objects during the design process. However, when objects designed with different CAD packages meet each other in one model, they don't know how to communicate.

The International Alliance for Interoperability (IAI), a consortium of the building industry and all major Architectural and Engineering Construction (AEC) software developers, is addressing this mismatch by specifying interoperable standards for the definition of objects in the AEC industry. The IAI defined the so-called Industry Foundation Classes (IFCs ) as the basic parts of CAD objects that make up building facilities. The goal is to improve the design and construction process as well as maintenance in the building industry.

The IAI uses the data description language Express (ISO-1303 part 11) to model IFC objects. One key principle in defining IFCs is to use implicit geometry (i.e., to describe objects by parameters defined in the basic IFC model).

Implementations of IFC 1.0 debuted at this year's ACS show in Frankfurt in November. These first trials used the Standard for the Exchange of Product data (STEP) physical files for the exchange of models, but future versions will also support OLE/Common Object Model (COM) and Common Object Request Broker Architecture (CORBA).

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For More Information

If you want more information
 on the IAI, you can check 
out the Web site at 
http://www.interoperability.com
.