Nyamweya is a Kenyan scholar who has done many years of research on a diversity of topics
Over the recent years, the cost of housing has been increasing rapidly and that it constitutes as one of the major factors that have made housing unaffordable to most low and middle-income earners. The building materials form a necessity for construction and it is estimated, according to Marion (2007), that they make up for over 60% of the total construction cost. If building materials consist of such a large proportion of the total construction cost, reducing their costs as much as possible is an imperative step to achieve low cost housing. According to AfDB (African Development Bank), the construction industry is affected by the high cost of building materials prices. Due to the high cost of building materials, the cost of residential construction has increased which mainly affects low- and middle-income earners. Conventional building materials are beyond the reach of most of the global population due to their lack of affordability. In addition to this, the increase in the cost of building materials, escalating environmental concerns due to the far-reaching misuse of natural resources linked with general construction and other housing development programs impulse the need to look for alternate technological options that can be applied in the construction of affordable housing. Substitute methods, materials, and practices of construction replacing conservative building and construction can amount to tumbling the depletion of natural resources and save energy. Research made by Cytonn (2018) claims that governments are more likely to employ ABT (Alternative Building Technology) such as EPS (expanded polystyrene) technology and precast concrete panels to reduce the construction time. Reduced construction time allows fast mass production of housing. Limitation of ABT would be a general conviction that the utilization of the technology does not differ from conventional technology.
The prefabrication system is a high efficient construction method due to the fact that the units are manufactured offsite. Since their manufacturing is done under specialized conditions, the quality of the units is relatively high compared to any unit that may be constructed on site. The units are transported to site when ready for installation. Since most units are made into near square shape, they are easy to pack into stacks and transport considerably a large number of units to the site using trucks. When carefully packed, there are hardly any damage imposed on the units. Compared to the conventional construction methods where scaffolding and formwork are usually used -They add to the time and cost of building and the materials are sometimes not recyclable- the prefabrication system do not require any formwork and scaffolding to install. Precast. Material wastage on site is also minimized.
There is need of only a few workers on site who are deployed during the installation period. This is advantageous compared to conventional methods where there are many labourers especially during concrete pouring.
Cytonn Research, 2018, Affordable housing in Kenya. [Online]