“…As their income level improves, they upgrade shanty dwellings over time into more substantial houses (Turner, 1968;Klak and Holtzclaw, 1993). In a number of countries with continuing urbanization, intermediate or peripheral zones have become the major destination for new migrants (UNCHS, 1982;Conway, 1985;Gilbert and Varley, 1990;van Lindert, 1991). Overall, the periphery location is characterized by squatter settlement or self-help housing.…”