House designers are faced with the task of giving form to an enclosure that is basically designed to provide shelter for dwelling, an activity continually subject to change in its composition and operation. Bernard Leupens study takes the permanent or the durable components of a house as its departure point and designates these aspects as the frame those factors which define the generic space and in which change can occur. This theory, which is developed using an analysis of over 30, well documented projects, follows in a Dutch tradition of studies into the flexibility and changeability of dwellings.