What does computer aided design offer for producing livable buildings in the 21st century?

Designing livable buildings has always been a major concern for architects but they are often criticized on account of failing in this aim. However, this is not only due to the ignorance of the designers, but also of the complexity of the factors that are essential to design but difficult to incorporate the design process. Buildings are shaped and occupied under several dynamically changing conditions and paper-based media and conventional Computer Aided Design (CAD) tools are inefficient in representing them. This paper aims to discuss the changing role of digital media for architectural design in response to the increasing complexity of design processes. Some proposals, supported by recent technological innovations, are suggested for the future and they are compared with the conventional uses of CAD. It is claimed that in the 21st century, the main advantage of using computers will be to dynamically simulate buildings in time in highly visualized virtual environments to evaluate the future performance of proposed designs. The design model will not only look as if it were real, but it will also “behave” as if it were real so as to provide dynamic and intelligent response. The two key technologies for the development of such modelling, virtual reality and object-oriented programming are addressed and four promising application areas for near future (evaluation of user-building interaction, visualization of environmental factors, construction scheduling, and combined CAD-GIS) are discussed. Some important considerations for the development of dynamically simulated virtual models are analyzed and suggestions are made for further research