ROOS1 -- Version One of a Generative Expert System for the Design of Building Layouts

ROOS1 is a generative expert system for the design of building layouts. The system is intended to complement human designers'performance through (a) its ability to systematically search for alternative solutions with promising trade-offs, and (b) its ability to take a broad range of design concerns into account. Work on the system provides insights into the applicability of Artificial Intelligence techniques to space planning and building design in general. The system is based on a general generate-and-test paradigm. Its main components are a generator, a tester and a control strategy (which is to be expanded later into a genuine planner). The generator is restricted to the allocation of rectangles. The spatial relations above, below, to the left and the right are defined for pairs of objects in a layout and serve as basic design variables which define differences between solutions and govern the enumeration of alternatives. Within the class of layouts it is able to produce, the generator is completely general and able to generate all realizable sets of spatial relations for a given number of objects. In contrast, the tester is domain-specific and incorporates knowledge about the quality of layouts in a specific domain. The system can be applied to various domains by running it with the appropriate tester and, possibly, the appropriate control strategy. The control strategy itself mediates between planner and tester and, when expanded into a planner, is able to streamline the search for alternatives. The system will go through a sequence of versions with increasing complexity. Each version will have a conceptually clean and clear architecture, and it is the authors'intention to evaluate each architecture explicitly in terms of its promises and limitations with respect to various domains. The first of these versions is described in the present pape