The paper presents an approach to the problems of architectural design aided by Artificial Intelligence techniques that can solve the difficulties related to combinatorial explosion, often encountered in the past. Three expert systems, dubbed “reasoners”, capable of some elementary design work and a hypothesis for their interaction have been developed. Reasoner A has an “analogical” view of space. A notion of conflict, managed by means of fuzzy logic, has been introduced. It corresponds, in an intuitive and straightforward fashion, to the common notion of conflict or contradiction in real space as a consequence of improper overlapping of actual physical objects or of their functional pertinence. Reasoner B works on formalized models of building objects. It designs new patterns from given patterns taken as defaults. Reasoner C picks up from an archive of patterns the one which best suits a list of given goals. Design is the result of interaction between the three reasoners. Finally, the proposed schema raises questions about formal structures (“images”) and about the nature of culturally-linked options (“memory”) on which some preliminary considerations are made. Prototypes of the reasoners are operating at the Instituto di Edilizia of the University of Ancona, Italy.