ABSTRACT
The creative use of state-of-the-art CAD technology on structures such as the Guggenheim Museum in Bilbao has realised ambitions in CAD that have lain dormant since the 1970s, the central principle of which was that of the integrated CAD system. This radical and ambitious concept first arose in the early days of CAD when computing power was comparatively weak, but architectural aspirations high. The aim was to be able to describe a design from inception to production entirely within the CAD environment. The emphasis was less on particular design functions and more on the expression and manipulation of design information to serve all possible functions. Although serious attempts were made to develop integrated CAD software to support the design of particular building types such as hospitals (OXSYS, used by the Oxford Regional Health Authority), and houses (SSHA, the Scottish Special Housing Association), they suffered from the effects of having to fit the users to the available software, rather than the other way round (Bijl, Stone, Rosenthal, 1979). Invariably, users had to conform to using systems that anticipated precisely how buildings would be perceived, down to a level of fine detail. Such systems were characterised as prescriptive (Bijl, 1989).
