|Journal of the Network of African Countries on Local Building Materials and Technologies - Volume 1, Number 4 (HABITAT, 1991, 48 p.)|
* By A.A. Hammond, M.Sc. Dr. Tech. Sc., Deputy Director/Head, Materials Dept., Building and Road Research Institute (CSIR), Kumasi, Ghana.
This paper was presented to the Third International Seminar on Structural Masonry for Developing Countries, held in Mauritius, July 1990.
It is an abridged version of the original report included in the Proceedings of the Seminar.
All African countries, regardless of their social, economic and political conditions, are confronted with an acute problem of housing, because they all face similar developmental challenges. In Africa, as in most developing regions, there are large numbers of people without any form of shelter at all or living in deteriorated or unimprovable shelter conditions. While the situation is felt by the majority of the population, the most affected are the low-income earners, the unemployed and underemployed.
African countries, in many instances, have adopted highly mechanized and capital-intensive production facilities in an attempt to meet the ever-increasing demand for building materials. Furthermore, the failure of large-scale production, in many instances, to meet the rising demand and to operate efficiently, has forced many African countries to import building materials as a last resort. This unintended dependence on imported building materials and technologies has led to an excessive drain on foreign exchange and has led to serious shortages, because of the inability of governments to allocate funds for imported materials and production inputs (1), (2).
One way to improve the situation is by making basic materials available in sufficient quantities, and at affordable prices, to prospective builders, including low-income earners. The main focus of this paper, therefore, is to identify and discuss housing problems in Africa, and prospects for solving these problems, as well as strategies to be adopted to produce building materials for an increased production of houses.
Some of the problems concerning housing in Africa may be identified as basic and pertaining to the economic development of the continent. Other constraints may be peculiar to housing, although they may be a result of the former.
The main developmental constraints in Africa are economic, high population and urban growth rates, environmental degradation, and natural disasters, all of which directly or indirectly affect housing conditions.
There is not a single African country that is not suffering from a crushing debt-service burden of some sort, shrinking foreign investment, rising rates of interest, and unfavourable trade terms for traditional exports (3). The prices of primary commodities are declining on the world market, while the prices of imported commodities from developed countries are increasing continuously. In this situation, the pound Sterling or United States dollar values of African exports always lag behind the price of imports urgently needed for capital and work equipment in construction programmes.
High population and urban growth rates also account for the inability of African countries to cope with their housing needs. An increase in population demands an increase in housing and other infrastructural facilities such as transport, hospitals, schools and factories. Natural disasters such as earthquakes, hurricanes and floods, can, within a few moments, reduce the number of the already inadequate existing housing stock. This invariably leads to overstretching of already meagre resources which could otherwise be used for housing, for example.
Problems directly associated with housing
Constraints leading to housing problems may be outlined as follows:
· Population growth with increasing urbanization;
· Shortage of housing finance;
· Land tenure and cost;
· Unavailability and high cost of imported building materials;
· Low incomes of prospective buyers;
· Low priority for housing in the construction sector.
Of these constraints, land tenure, housing finance and availability and cost of building materials may be identified as the most important ones.
In the development plans of most African countries, the production of building materials to serve the housing needs of the vast majority of the population has never been given the priority accorded to it in the Lagos Plan of Action for Africas Development (LPA) 1980-2000. Yet, it is an area which touches on many of the objectives that the LPA aims to achieve, such as the following:
· Increased self-reliance;
· Effective mobilization of human resources;
· The creation, in each Member State, of an industrial base designed to meet, among other things, the satisfaction of basic needs of the population, the exploitation of local natural resources and the creation of jobs;
· Cooperative efforts by Member States in the development of their natural resources to meet socio-economic needs of their peoples;
· Rational development of the building materials and construction sector;
· The encouragement of women in housing construction.
The International Year of Shelter for the Homeless (IYSH) confirmed the need to intensify national and international efforts to deliver and improve shelter for all with specific emphasis on the poor and disadvantaged. The Global Strategy for Shelter to the Year 2000 should be seen as yet another opportunity for African countries to tackle the shelter needs of the poor in an action-oriented approach, based on a global interaction (2).
External plastering of a stone wall
The demand for local building materials
Statistical data in the consumption of local building materials in the countries of the African region are not easily available. The general indication, however, is that there is insufficient supply to meet the demand for some materials, such as burnt bricks. The demand for other materials, such as lime and stabilized soil, has to be stimulated in many countries.
There is much use of burnt bricks in countries where the tradition of artisanal brick production has been established over many years and a large number of producers are involved. In Malawi, burnt brick is the most popular walling material used in the construction sector for both public and private construction. In Madagascar, it is estimated that over 12.5 million bricks are consumed annually.
In Nigeria, burnt bricks have gained increasing popularity in recent times, because of directives issued by state governments that bricks should be used in the construction of public buildings and government housing projects. The consumption of bricks in Southern Nigeria increased from 41.7 million units in 1982 to 74.5 million in 1986, showing an annual growth rate of almost 16 per cent. The consumption is now about 98 per cent of production. The current brick-production levels in some countries are well below the demand and, for example, in Ghana, orders for factory-made burnt bricks take a long time to be delivered.
The current use of lime in construction is low, as is that of pozzolana. The potential for their use, in combination, as a low-cost binder, is, however, enormous, considering the high cost of cement in many countries and the shortages in supply that are often experienced. Another source of demand for lime is stabilization of soil for building blocks and, also, in road construction. Stabilized soil blocks/bricks have, also, gained popularity in some countries, including Burkina Faso, Cameroon, CdIvoire, Ghana, Kenya, Madagascar, Niger, Nigeria, Togo, Uganda and United Republic of Tanzania (2), (4). Currently, there are large-scale projects in Madagascar and Uganda where stabilized soil blocks are being used. Stabilized soil is also known to have been used in projects in other countries like Mali and Zambia.
A measure of the competitiveness of local building materials is their cost advantage over popularly used materials. Experience in Nigeria shows that large-sized brick products are more competitive than the sandcrete blocks. A major reason for this is that the present generation of masons in Nigeria, as in other countries, have little experience in the laying of small-sized bricks. Laying costs are, therefore, high compared with the large sandcrete blocks (2).
Constraints due to unavailability and high cost of building materials
Building materials constitute the single largest input in housing construction, sometimes accounting for as much as 75 per cent of a low-cost house. However, in most African countries, popular materials are inadequate in supply and high in cost. The traditional materials are of low quality and unpopular; research innovations have not as yet been translated into marketable products. The consequence of all this is that the large majority of the population lives in deplorable shelter conditions or have no access to basic shelter at all. Unfortunately, the shelter crisis is worsened by the unfavourable patterns in general population growth and the high rate of migration to the urban areas, so that, despite efforts by governments to improve the situation, there is rather a steady rate of deterioration in this sector.
One of the underlying reasons why the building-materials sector continues to be a bottle-neck in low-cost housing delivery is that there is a high degree of import-dependence in established production units while abundant opportunities for adopting truly indigenous production systems remain only marginally exploited. So far, a few African countries have made the effort to promote building-materials production units based on indigenous factor inputs. But, this has always been on a relatively marginal scale, partly as a result of inadequate local resources but, mainly, because of the lack of an effective strategy for expanding and developing the local building-materials sectors. The building-materials industry can contribute significantly to national economic recovery. However, it has been a drain on scarce foreign-exchange earnings with an estimated US$ 3 billion being spent per annum on imports of building materials over the past five years (5), (6).
In many countries, a wide variety of raw materials is available in sufficient quantities. However, most of these raw materials have remained inaccessible for full-scale exploitation due to several constraints. Notably, there is lack of data on materials characteristics and there are institutional as well as financial barriers to raw materials exploitation. Similarly, existing technologies have not readily been adapted. In addition, there is insufficient trained labour to carry out the bulk of activities required for the development of the building-materials sector.
Factors militating against use of local materials
Factors affecting the use of local building materials may be identified as technical, economic, socio-cultural and institutional. Some of these factors affect the acceptability of local building materials but are closely related. For convenience, they are discussed separately.
The technical problems associated with the use of locally available building materials make a considerable contribution to the degree of acceptance of the materials for housing. For example, the tendency for earth to absorb water with corresponding decrease in strength, leads to rapid deterioration of earth buildings. This alone is a stumbling block for a wholehearted acceptance of earth for housing despite the availability of techniques and processes for improving the materials for use. Similarly, wood, due to its susceptibility to termite and fungal attack, and other biodegeneration tendencies, as well as fire hazard, is not as popularly used for housing as it should be.
Most of the population in any country in Africa does not have the economic capacity to acquire modern housing, and many families resort to self-help housing in order to reduce costs. Under these circumstances, a high financial sacrifice is required and all the risks associated with the construction of the building is borne by the owner/builder. For this reason, an individual would be cautious about the kind of material used and the type of technology adopted for constructing a building to avoid any risk of failure or total collapse of the building (6).
The rate of housing construction, the quality of the housing units, and the adequacy of amenities provided to make a decent living environment, relate to the financial capacity and the level of income of the people. Since the level of income of the bulk of the people in Africa is low, only a small percentage can finance the construction of their houses without depending on financial institutions for loans. Therefore, the bulk will require loans from financial institutions which will, in turn, require that the house be built with conventional materials such as brick or concrete rather than, say, earth. This factor alone contributes considerably to the unacceptability of earth for housing (5), (6).
Building regulations, standard specifications and codes of practice in many African countries do not encourage the use of local materials such as earth for housing in the urban areas. Besides, the standards of the properties required for housing by the building regulations and codes are higher than can be obtained with some of the local materials.
Stabilised soil-block wall construction, Cote dIvoire
Prospects for developing building materials industries in Africa to improve the housing situation
Despite the problems and constraints discussed above, the prospects for increasing production of local building materials are great. The African continent is rich in raw material resources for building-materials production. Potentially, the continent has all the necessary raw materials needed for producing building materials. There are vast deposits of soil, laterite, stone, clay, limestone, gypsum, pozzolana, iron, bauxite, copper, zinc, asbestos and wood from which building materials could be developed. What is needed is a strategy to encourage producers to increase their productivity, improve the quality of products and expand the sector so that it can meet the immense demand in the continent.
Strategies for developing building materials in Africa
Before strategies are worked out, governments of African countries should be fully committed to a long-term programme for the development of the local building-materials industry. This commitment should result in clearly defined policies backed by adequate allocation of funds to ensure successful achievement of targets of the industrialization programme. Other important prerequisites for achieving these goals are, development of research and information infrastructures, which will provide suitable technologies, assistance in standardization and quality control, formulation of relevant building codes and regulations and dissemination of information to various user-groups. Other prerequisites include workforce development and training to provide managerial and technical skills to cope with requirements to technologies adopted. Manufacturing of tools and spare parts for equipment and machines, should also be developed (6), (7), (8).
In order to improve the housing situation in Africa, three major strategies for increasing the availability of building materials should be adopted. These are as follows:
(a) Efforts to achieve better utilization of already installed production capacities based on thorough evaluation of problems of plant in order to find necessary remedial measures;
(b) Establishment of new building materials plants must be preceded by thorough feasibility studies, coupled with diversification and decentralization of production technologies.
(c) In situations where minimum plant sizes exceed the requirements of one individual country, multi-country plants for the production of specific building materials should be established. Examples are joint cement projects (CIMAO) by CdIvoire, Ghana and Togo and another joint cement project (SCO) by Benin and Nigeria. Building materials standards should be harmonized to facilitate trade in building materials within the African region (8), (9), (11).
Constructing walls with stabilised soil-blocks, Gabon
Promotion of use of earth as a strategy for improved housing in Africa
What strategies should be adopted in promoting the use of improved earth for housing? Fortunately, most of the technical problems associated with earth as a material for housing have been identified and solutions found for them. The physical properties of earth may be improved by cement or lime stabilization. When this is combined with good and adequate design for foundations, wall and roof, earth as a building material can favourably compete with other building materials. When these measures are taken, maintenance costs will be drastically reduced and its status as a social symbol will be enhanced. As a result, financial institutions may become favourably disposed to giving loans to builders who decide to use improved earth for housing.
The solution of the socio-economic-cultural implications seem to be difficult and slow but, once the economic one is in motion, the socio-cultural ones will follow. It will be necessary that government buildings in the rural areas such as clinics, schools and bungalows for civil servants be built with improved earth. These will be examples for the people in the area to adopt. It will be important, also, to involve the rural community, at every stage of such construction programme with local councils providing guidelines on technical matters. The institutional problems can be tackled by revising the existing building regulations and codes so as to take into account the use of local building materials, such as earth for building in urban areas. This effort should be backed by results from research (14), (15), (16), (17).
Promotion of small-scale production of local building materials as a strategy for increased production of housing in Africa
An adequately developed building-materials industry is needed in each country in Africa to contribute to the economic growth of the country. The small-scale building-materials sector is an integral part of the building-materials industry and contributes substantially to it. The basic advantages of small-scale building materials production technologies in comparison with large-scale alternatives may be summarized as follows.
· Low dependence on sophisticated managerial skills;
· Low energy requirements;
· Ability to use new and renewable forms of energy;
· Flexibility to adapt labour-intensive production methods and ability to utilize, otherwise non-viable, small-scale deposits of raw materials in a variety of locations;
· The potential to locate small-scale units at widely scattered points, suitable to the pattern of construction activities, thereby reducing transportation costs is an additional advantage.
If small-scale production of building materials is to play a pivotal role in a strategy to improve the housing situation in Africa, then, the following aspects should be considered:
(a) Low-rise and high-density development housing in urban locations have the potential to promote the use of materials from small-scale industries;
(b) Land-zoning policies and land-use patterns can have a great impact on the type of materials used in housing construction;
(c) Policies related to credit facilities for housing construction, especially the materials used and type of dwellings approved for loan purposes, influence the choice of materials for building a house;
(d) It is possible to build more dwelling units with available financial resources, if local materials from small-scale units are used;
(e) Organization of self-help and community based housing programmes are feasible in large numbers, if the production of materials is also organized at the community level. This can lead to noticeable cost reduction.
Another strategic area for consideration is the dissemination of technical information. Technical information is very useful to communities that want to undertake self-help housing programmes to enable them to construct affordable, safe and durable shelter. It is necessary to have housing extension services, just as there are agricultural extension services in the agricultural sector. A housing extension services unit would teach and demonstrate how to build houses economically.
Finally, another strategy that should be adopted to enable the improvement and increased production of housing is training. A deliberate effort should be made to train young artisans to replace the old ones in different areas of technology (5), (6), (8), (11).
Construction of houses with stone masonry, Kenya
Africa is facing a crushing debt-servicing burdens, shrinking foreign investment, rising rates of interest and declining earnings from their exports. Since, in many African countries, building materials have a high degree of import-dependence, and since this relies on the foreign exchange earnings of these countries, when their foreign earnings become limited because of the adverse effects of inflation or by some economic crisis, then, the construction industry suffers. For these reasons, the main focus of this paper has been on the prospects and strategies to increase production of local building materials for housing in Africa. Constraints leading to problems in housing have been highlighted, some of which include rapid population growth and the high rate of migration to urban areas, land tenure and cost, housing finance, the low income of prospective house buyers, and the low priority for housing in the construction sector. Factors militating against the use of local building materials have also been highlighted.
Prospects for developing the building-materials industry for increased production of houses have been found to be good. The continent of Africa has all the necessary raw materials, including fuel and power, for building-materials production. Of the strategies identified, a few that should be mentioned include the promotion of the use of improved earth for housing and promotion of small-scale production of local building materials, to increase production of housing in Africa. Other prerequisites discussed include the full commitment of African governments to ensure a long-term programme for the development of the workforce and training to provide managerial and technical skills to cope with the requirements of the technologies adopted. Other important prerequisites for achieving these goals are: development of research and information infrastructure to provide suitable technologies, assist in standardization and quality control, formulation of relevant building codes and regulations, and dissemination of information to various user-groups.
1. United Nations Centre for Human Settlements (Habitat), Executive Summary of the Global Report on Human Settlements (Nairobi, 1988) 45 pp. (HS/129/88E).
2. United Nations Economic Commission for Africa, Draft programme of action for the development of building materials industries in Africa to the year 2000 (Addis Ababa, 1988) (E/ECA/HUS/34).
3. United Nations Economic Commission for Africa, African alternative framework to structural adjustment programmes for socio-economic recovery and transformation (AAF-SAP) (Addis Ababa, 1989) (E/ECA/CM.15/6/Rev.3), 53 pp.
4. United Nations Centre for Human Settlements (Habitat), Habitat News (Nairobi) vol. 10 (1988), No. 2.
5. Hammond, A.A., Prospects and strategies for local building material development in Africa, Proceedings of CIB 86 (Washington, D.C., 1986), vol. 5, pp. 1771-1778.
6. Hammond, A.A., New strategies for housing the homeless in the developing countries, with particular reference to Africa, Seminar of Housing for the Greatest Number - International Year of Shelter for the Homeless, Kinshasa, 1987.
7. United Nations Economic Commission for Africa, Needs, constraints and prospects of African countries regarding the availability of building materials, Proceedings, International Symposium on Appropriate Building Materials for Low-cost Housing, vol. 2 (Nairobi, CIB, RILEM and UNCHS (Habitat), 1983), pp. 8-15.
8. United Nations Economic Commission for Africa, Components of the policy and strategy for the development of construction and building materials industries (Addis Ababa, 1978) (E/CN.14/HUS/28), pp. 1-14.
9. United Nations Economic Commission for Africa, Construction and building materials industries in Africa (Addis Ababa, 1978) (E/CN.14/HUS/22), pp. 1-20.
10. Food and Agriculture Organization of the United Nations (FAO), State-of-the-art in Building Materials - African Region (Rome, FAO), pp. 1-27.
11. Hammond, A.A., Development of the building materials industries in Ghana, Conference of African Experts on Building Materials and Construction Industries in Africa, Addis Ababa, 1979.
12. Hammond, A.A., Technology alternatives for production of bricks in developing countries, RILEM/CIB Symposium on Appropriate Building Materials for Low-Cost Housing in the African Region, Nairobi, November 1983.
13. Hammond, A.A., Pozzolana cements for low-cost housing, Proceedings of International Symposium on Appropriate Building Materials for Low-cost Housing, vol. 1 (Nairobi, CIB, UNCHS (Habitat) and RILEM, 1983), pp. 73-83.
14. Hammond, A.A., Lateritic soils for rural housing, Building International, vol. 5 (1972), No. 3, pp. 162-166.
15. Hammond, A.A., Prolonging the life of earth buildings in the tropics, Building Research and Practice, CIB Journal, vol. 1, (1973), No. 3, pp. 154-163.
17. Hammond, A.A., Acceptability of earth as a material for housing in Africa, Proceedings of the International Colloquium on Earth Construction Technologies Appropriate to Developing Countries, Brussels, Belgium, 1984, p. 9.
18. Government of Botswana, Building Materials Sector Study (Gaborone, Ministry of Commerce and Industry, 1983), pp. 1-128.