This text presents a range of concepts and practical methods for housing with illustrative examples of actual projects, where resources are scarce, demand is high, urgency is acute, and where uncertainty is a way of life. The book shows that under these conditions, efficient practice depends upon methods that promote rather than hinder spontaneity, improvization, and incremental development. The author explores what the changes taking place internationally in housing policy are, why and how they have emerged, and what impact they now have on design and on the attitudes, skills, methods, and tools of designers. The book shows how plans can emerge in action without a preponderance of user surveys or master planning, and how the three themes of participation, flexibility, and enablement can together improve the efficiency of practice and promote an architecture of co-operation.