The main aim of this project is to create a system based on graph transformations which supports architects in the early phase of architectural design called conceptual design.
Our system, GraCAD (Fig. 1a and Fig. 1b), helps the architect to create a prototype design that fulfils a given set of high-level requirements. GraCAD is integrated with the commercial program for architects ArchiCAD. The graph-based knowledge representation of family house requirements and corresponding layouts forms the theoretical background of our system. The graph rewrite tool PROGRES developed at the Aachen University of Technology is used to manipulate these graph representations and to translate high-level requirements graphs into low-level graphs reflecting the internal data structures of ArchiCAD.
In GraCAD system PROGRES prototype

• provides access to the domain knowledge stored in the form of a graph grammar
• provides means of constructing graphs that describe the currently designed object
• allows the user to trigger rules that check whether the current design fulfils architectural norms and other constraints.

Further GraCAD development will be continued in a co-operation of architects from the Institute of Computer Modelling at Cracow Technical University. In collaboration with them we will attempt to find useful checkers, various design adjustment generation strategies and realistic design constraints. As a result of the research we intend to create a tool useful in praxis that aids designing objects more complex then a single-store family house.

• Realtime Systems Lab, Technische Universität Darmstadt, Darmstadt, Germany

• Department of Computer Science III, Aachen University of Technology, Aachen, Germany

• Institute of Computer Science, Jagiellonian University, Krakow, Poland

• Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland