The housing problem in South Africa is complicated by the cultural diversity and the rapidly changing nature of the population. This indicates a need for research to help to determine "what appropriate housing is" for various sectors of the South African population. Social researchers and design professionals therefore have to combine their efforts to provide house designs that will be appropriate to the housing needs and values of a variety of future occupants. This study focuses on the impact of rapid change in the sociophysical environment (modernization) on people's experience of the quality of their relationship with their home environments. An approach is proposed through which groups of individuals, who share similar needs and requirements regarding their housing, can be identified for inclusion in a process of participatory design. A theoretical framework is developed to account for the variety of perspectives of participants (users, researchers and design professionals) in the design process. Through application of the theoretical framework, a novel approach to the determination of "what to design for whom" is developed. The "modernity fit" concept is introduced to describe the quality of the relationship between people and their housing in terms of a rating of the modernity of both human and housing characteristics. It is proposed that the quality of the relationship or "fit" between the modernity of human characteristics and the modernity of the physical characteristics of the house influences people's experience of their houses. Results of this study indicate that the "modernity fit" concept opens up new avenues for research to assist in the design of housing in developing countries. / Psychology / D. Litt. et Phil. (Psychology)