This paper presents an intelligent CAD system for integration morphological and thermal considerations involved in the making of architectural form. A shared knowledge base is at the core of the proposed system. The system is designed to allow independent modules that target the different aspects of a building design and analysis (e.g. thermal analysis and morphological analysis) to access and modify the knowledge contained in this knowledge base. The paper discusses the structure of the system and issues pertaining to its implementation. An example of the use of the system is illustrated. Conclusions and findings about the utility of the system are drawn.