Towards an Architectural Design System Based on Generic Representations

Computer Aided Architectural Design systems offer a broad scope of drawing and modeling techniques for the designer. Nevertheless, they offer limited support for the early phases of the design process. One reason is that the level of abstraction is too low: the user can define walls and such in great precision, but no support is offered to define global or structural characteristics of the design. In previous research, structuring representations such as zones, grids, and axial systems, as well as object representations such as element vocabularies and contours have been identified as formative elements in architectural design. They have been defined and described as socalled graphic units. Furthermore, sets of graphic units form generic representations, in which the relationships between graphic units are well defined and meaningful to the architect. Graphic units and generic representations, or their equivalents, are not supported in current CAAD systems. In this paper, a system is proposed that is based on graphic units and generic representations. It has tools for making graphic units and also provides a way to define and maintain changes in the relations between graphic units. This is implemented on the basis of a graph representation where the nodes represent graphic units and the edges relations between graphic units. Changes in the graphic units are propagated through the graph. The paper shows how the theoretical work on graphic units and generic representations leads to the current implementation. The system structure is explained and the way changes in graphic units are propagated through the graph representation. TOWARDS AN ARCHITECTURAL DESIGN SYSTEM 3