The role of improved indigenous building materials and construction techniques in lowering the cost of house construction:A case study of a demonstration housing project in Hakati and Mbita divisions of western Kenya

Abstract

As in many other developing countries around the world the need for housing in Kenya's urban and rural areas, which is predominantly characterized by insufficiency both in terms of quantity and quality, is growing at a faster rate than it can be satisfied. Its growth can be attributed to many different factors, but one of the major .ones is that the cost of conventional house construction continues to rise above the ability of most people in Kenya to pay for such housing. In fact, rising construction costs can be directly attributed to increases in the cost of building materials and labor which account for nearly 82% of the total cost of a conventional housing unit. Realizing that the total cost of house construction can be decreased significantly by decreasing the cost of these two elements, many housing research organizations around the world have been investigating the degree to which the use of low-cost local building materials and construction techniques and local community participation can reduce the costs of house construction. In Kenya, the Housing Research and Development Unit at the University of Nairobi has demonstrated the use of stabilized soil-cement blocks, corrugated sisal-cement roofing sheets, and local community participation in the (vi) construction of ten teachers' houses in Hakati and Mbita constituencies of Western Kenya. The purpose of the demonstration project, also known as the Improved Rural Technology (IRT) project, was to transfer appropriate low-cost housing construction technologies to rural communities and establish some means (in this case housing co-operatives) through which the communities could continue to replicate the technologies in the construction of more teachers' houses in the future. This study examines the degree to which the use of improved indigenous building materials and self-help labor in the IRT project was actually able to lower housing costs. However, since the total cost of each housing unit was dependent on many factors such as the speed of project implementation, the quality of the houses, and the degree to which original project objectives were achieved, the role that appropriate technologies and community participation played in lowering the cost of house construction is evaluated in light of these factors. An evalaution of the IRT project reveals that the use of soil-cement blocks and sisal-cement roofing sheets which are produced on site can reduce the cost of conventional house construction by approximately 26% and yet maintain a high standard of housing quality. Because of the technology's local acceptability, appropriateness, and reasonable cost for teachers' housing; the housing co-operatives in the two constituencies plan to continue to (vii) use the technology in constructing more teachers' houses in the future. But in order to increase the efficiency of future replication activities, some changes will need to be made in the organization of the co-operatives and the procedure to be followed by them in constructing more teachers' houses. Recommended changes are presented in Chapter 6. In terms of reducing the cost of labor associated with the house construction process, the evaluation reveals that the IRT project was not a good demonstration of how local community participation can lower housing costs. In this project there was minimal community participation; both skilled and unskilled tasks were performed on a paid basis. Because of the need to pay unskilled workers and the low productivity of both skilled and unskilled workers, the total project expenditure on labor was nearly 8.5 times higher than had originally been expected. Hence, the cost reduction normally associated with the involvement of local people in house construction on a self-help basis never materialized in this particular project. The use of improved indigenous building materials and community participation can play a significant role in reducing the cost of conventional house construction. When incorporated in other low-cost housing programs such as site-and-service schemes and settlement upgrading, these two concepts will certainly contribute to the provision of housing which a greater percentage of the people in Kenya can afford.