Spatial and Nonspatial Consistency in Design Systems

This paper is concerned with problems that arise from attempts to integrate the components of a building model in a database that reflects the current status of a design. It is based on work that began in 1976 at the Architectural Research Laboratory of the University of Michigan. This effort, which was the work of many individuals, had as its goal the construction of an integrated computer-aided building design system. Many of these ideas have been implemented in a working experimental modeling system, ARCH:MODEL. From a series of both practical and theoretical experiences using and building this system several difficult questions have come up that need research attention. Among these are: how can a design database be made consistent and how can consistency, both spatial and nonspatial, be maintained as the design develops? These questions are related to the general problem of what is the relationship between the design process and the designed object. It is not the intent of this paper to provide answers to these problems but to argue for their importance and to provide some direction for research.