Construction of Low Cost Houses in Informal Settlements in Nairobi Region
Introduction:
Many African countries have experienced a large increase of urban population. Even though the shortage of Construction of Low Cost Houses in urban areas became a problem in Kenya already during the 1960s, due to massive urban migration, the population living in informal settlements has increased dramatically ever since. The urban population is expected to reach 50% by 2015, and the proportion of people living in informal settlements is in some cities very high, such as in Nairobi, with an estimated 60%. Despite numerous efforts from non-governmental organisations (NGOs) and recent governmental activities, the trend is yet to be reversed.
The project was carried out as a field study in Nairobi during September-November 2013. It evaluates four current or recently completed slum upgrading housing projects in this region. It has a technical perspective, while other also important aspects, such as political and economic influences, are not included in the scope. The results show that many appropriate house designs, implementation methods and building materials are available, but not always all applicable or suitable in any given housing project. High rise concepts have proven to be devastating for the social and commercial environment of its tenants, while smaller multi-storey houses, with one household living in each, represent an alternative in densely populated areas. Long term, incremental expansion can also be an advantageous concept.
Slum Upgrading Construction of Low Cost Houses in Kenya:
Housing is, in a similar manner, only one area in a larger context of physical infrastructure, among roads, sanitation and access to water. These aspects are all essential for successful slum improvement, but are not included in the scope of this thesis. It is, however, important to understand how all those factors influence and determine the outcome of upgrading activities.
Informal settlements:
There are many conditions that can be used to describe informal settlements/slum areas. Slums in Kenya are characterised by overcrowding, high unemployment and crime rates, unhealthy environmental conditions, and insufficient access to basic infrastructure, such as water, sanitation, housing and roads. The United Nations Human Settlements Programme uses a model to measure the degree of deprivation of basic infrastructure for households in urban areas. The model is designed to facilitate quantitative assessment of an area’s living standards and is based on five conditions:
1. Durable housing of a permanent nature that protects against extreme climate conditions.
2. Sufficient living space which means not more than three people sharing the same room.
3. Easy access to safe water in sufficient amounts at an affordable price.
4. Access to adequate sanitation in the form of a private or public toilet shared by a reasonable number of people.
5. Security of tenure1 that prevents forced evictions.
Application of appropriate technology Construction of Low Cost Houses:
In many developing countries, building material compose the main part of the total cost in residential housing construction projects. Reaching around 68% in Kenya, it is obviously a factor with great cost reduction potential. Field demonstrations and real life housing projects have proven certain designs to save up to 50% of the building material cost, including material acquisition and labour. Nonetheless, the dissemination of alternative, low cost building materials and methods has been very slow, and partially restrained, due to several reasons.
Alternative construction techniques Construction of Low Cost Houses:
The high demand for low cost housing in Kenya has, as mentioned, pushed the research on alternative construction techniques forward since the 1970s. The research has, however, had a relatively small impact on the construction industry as of yet, as stated by Syagga (1993). New materials and methods may get little attention even though they have many advantages compared to conventional design.
Stabilised soil:
Soil has been used as building material by several cultures for thousands of years. Unprocessed earth materials are very sensitive to erosion, but developed forms, such as sundried earth blocks (adobes) and kiln-fired bricks, can be very durable. Today, brick construction is still common, but the production is considered unsustainable because of deforestation related to the burning process. Stabilised soil technology offers an alternative in regions where this poses environmental degradation.
Concrete slabs:
Reinforced concrete slabs are a common flooring design in multi-storey houses in Kenya. It is an expensive design, since it usually requires lots of form work, raw materials, steel and cement, machines, transports, and skilled labourers. Because of both cost and potential complexity in implementation, standard concrete designs can be unsuitable for low cost housing projects.
Conclusion:
Considering the complexity of slum upgrading and Construction of Low Cost Houses, the possibility to actually produce a report that may be useful in its research field on such a limited timeframe is questionable. The thesis scope is hence of great importance, but the magnitude of available information on the subject indicates how the overall comprehension sets the levels of relevance and validity of the research. The narrower scope, the larger comprehension of the context in which it exists might be required.