In this paper the term 'community architecture' is taken to include the planning, design, development and management of environments with the active involvement of their users. The raison d'être is that a community architecture approach has short term and long term benefits for both the people involved and their environments. Because this approach usually involves changing existing roles and relationships for both designers and users, it is always a challenge and is often controversial. A review of the origins and metamorphosis of this approach in Britain and the United States will be presented, together with a discussion and comparison of selected community architecture projects studied in each country. The case studies will show that each community architecture project involves change - sometimes gradual, sometimes 'radical striking change' - for the people involved, for their environments, or both. The studies will also illustrate the variety of situations in which a community architecture approach has been applied. It concerns practitioners and/or academics, it can involve small scale or large scale environments, it can encompass a variety of disciplines and building types and has been undertaken with a variety of social/role relationships between designers and users. The paper will conclude with a discussion of the lessons from these case studies and from other recent research, for future environmental change taking a community architecture approach.