Part I. Explorations: Introduction; 1. The grid as generator Leslie Martin; 2. Speculations Leslie Martin, Lionel March and others; 3. Elementary models of built forms Lionel March; 4. The use of models in planning and the architectural design process Nicholas Bullock, Peter Dickens and Philip Steadman; Part II. Activities, Space and Location: Introduction; 5. A theoretical model for university planning Nicholas Bullock, Peter Dickens and Philip Steadman; 6. The modelling of day to day activities Nicholas Bullock, Peter Dickens and Philip Steadman; Part III. Urban Systems; Introduction; 7. Models: a discussion Marcial Echenique; 8. Development of a model or urban spatial structure David Crowther and Marcial Echenique; 9. A structural comparison of three generations of New Towns Marcial Echenique, David Crowther and Walton Lindsay; Afterword; Bibliography.