Abstract. Governments in developing countries will face increasingly serious problems in providing adequate shelter for the more than 25 million households that will be added to their urban populations by the end of this century A review of the magnitude of their housing deficits discloses the growing need for low-cost shelter. Public housing, sites-and-services, slum upgrading, and government assisted self-help-programs have failed to provide sufficient housing to meet the needs of the poor. These must be supplemented by programs that reduce the costs of housing construction and increase the participation of communities, the informal sector, and private enterprise in providing low-cost housing. Analysis of the results of conventional government housing programs offers little hope of an adequate amelioration of the problem.