Interoperability is one of the major themes of research and development in information technology for the architecture, engineering, construction, and facilities management industries. A model-based approach to interoperability requires information structures that are standardized throughout the industry. The industry foundation exchange technology for exchanging information using IFCs has now been established, but many areas require additional development before a comprehensive interoperability solutions is reached. These areas include: extending the application area beyond product data to project management data; extending the domain beyond buildings to civil infrastructure; extending the standards methodology beyond structuralist approaches to hybrid approaches; extending the communication layer beyond data dictionaries to transaction standards; extending the exchange mechanism beyond file-based exchange to distributed system architectures; extending the level of integration beyond data interoperability to integrated systems; and extending the form of information beyond homogeneous structured data to heterogeneous data and knowledge management.