This research concerns the floor plan designs of affordable housing units. In particular, the study considers the spatial arrangements and suitability of space based on household activities both in and around the homes of houses offered in the public housing schemes in developing countries (DC’s). Although there are various publications of research regarding spatial arrangements and floor plan designs, there is still a lack of research concerning households’ spatial demands. While adding to the existing literature that deals with spatial arrangements and floor plans, this study also addresses the issue of spatial demands. As a consequence of trends towards urbanization and population growth in general, the increased demand for housing, especially of the urban poor, has resulted in an increase in urban slums, marginal housing and shanty towns. Resettlement of low-income households to low-cost rental apartments is necessitated by a scarcity of urban land in big cities such as Surabaya, Indonesia. Land costs have risen while urban green and open spaces have decreased over the last decade. To accommodate this rising number of housing backlog, it is necessary that the housing for the urban poor be developed in multi-storied complexes as single-family detached or ground-bound individual housing can no longer be accommodated given scarce land resources in urban environments.

Apartments for low-income households in order to solve urban problems have been developed in a fast pace, particularly in Asian developing countries such as in Singapore, Malaysia, Philippines, Korea, including Indonesia (Laquian, 1979). Millions of tower housing complexes have been developed in recent decades. However, problems regarding this type of housing for the urban poor have become evident: given that low-income households result in small space housing. In spite of the increase in the unit size of the public apartments (from 18m2 initially to upwards of 32m2 more recently in Surabaya), the recent unit size is still considered below acceptable standards especially when such units should house more than four household members. Moreover, the space design (dimensions) should also accommodate the users’ changing needs over the course of time. In view of sustainability, functionality and adaptability of space design is a premise. Improving the functionality means sustaining the building function to cater to a household’s demand for space. Following Tipple (2000), it is nearly impossible to determine the actual space shortage of housing in the developing worlds, as not only insufficient data is available, but there is also little agreement amongst the countries relating to the units of measurement used or what constitutes adequacy (i.e. functionality). This research has attempted to fill the identified gap in knowledge by using the activity-based approach. This approach is based on the reasoning that household demands for space become apparent in their activities and the way they use space within the apartment unit. A household’s demand for space is achieved when adequate space has been provided for their activities.