Collective or communal housing (Cohousing) is housing featuring joint facilities available to all residents, while the residents also maintain autonomous, self sufficient housing units. The communal spaces form a central characteristic of the housing complex and is not just an added amenity. The shared facilities should encourage and accommodate social interaction, group activities and the coordination and cooperation between residents to carry out common tasks. A distinct infill level in buildings is gradually emerging. This level contains all the equipment, non load-bearing partitions and a substantial amount of services. The infill level restores the building as provider of space and shelter and facilitates the specific needs and preferences of the inhabitants more directly. Traditional notions of the family is being challenged, placing increasing demand on homes to be flexible and responsive to changes in family structure. Since the long-range benefits of a stable community is jeopardised if residents have to move when their spatial requirements change, transformable interiors were used to reduce this risk. Flexibility is largely used in the housing units, relying on advanced computed aided manufacture that is able to fabricate components for easy assembly on site. For the purposes of this thesis an under utilised office building in the Pretoria central business district was chosen to illustrate a cohousing complex in an urban environment. Design energy was focused on designing the communal facilities and a sample housing unit, illustrating the support system and investigating the unit's versatility.