Environment-behaviour studies are established as an academic discipline a worthwhile contribution to wake to design professions. There is still a need however for a coherent architectural theory which successfully embraces in reaching and practice, environment-behaviour concepts.The paper describes an environment-behaviour model which for some years has been used in teaching first year architecture students as the foundation of their architecture design work. The model is now finding it. way into public practice where its implications are shaping design attitudes and policies. The theoretical bases and assumptions of the model, and its practical outcomes are discussed.