Canadian Consulting Engineer


March 1, 1999
By Rosalind Cairncross, P.Eng.

The rusty sheets of corrugated iron lean crookedly against each other, a scattering of bricks and stones try to hold onto the shaky roof and the door dangles by a hinge. The floor is soft because it i...

The rusty sheets of corrugated iron lean crookedly against each other, a scattering of bricks and stones try to hold onto the shaky roof and the door dangles by a hinge. The floor is soft because it is made of sand. No window, no water, no toilet. This is home for hundreds of thousands of people in the Third World. For the housing industry, its planners and engineers, it is a challenge.

Shanty towns have sprung up on the fringes of numerous cities around the world. They cover the mountains in Rio and the plains in Cape Town. As the population grows and the countryside empties into the cities, the squatter settlements keep on growing. Cash-strapped governments cannot keep up. Housing has become a major problem — the kind of problem which some governments may be more inclined to tackle if the solution were practical and inexpensive.

Finding low-cost housing solutions is a problem that has engaged the more inventive members of the housing construction industry for years. But building a house which suits the climate, the client and the meagre pocketbook is no easy matter — especially with the meagre pocketbook. And what is inexpensive in one location may be costly in another. John Abbott, professor of civil engineering at the University of Cape Town in South Africa, is one innovator who believes that he has some of the answers for his part of the world.

The sandy, windswept plain which stretches south of the city of Cape Town is home to growing thousands of squatters. It is one of many informal settlements around the country. The government’s long term plan to address the housing shortage estimates that it will take at least 10 years to make up the backlog. Even this plan is probably wildly optimistic. Meanwhile, the peri-urban dwellers have to make do with inadequate facilities — unless, that is, they can do something about the problem themselves. The government has made self-help possible with a loan program. Professor Abbott is also trying to help solve the problem using innovative technology that has a social purpose.

The physical and social features of the informal settlements around Cape Town are captured on the geographic information system (GIS) maps that Abbott uses to track developments patterns. These maps show that the squatter settlements have doubled in size between 1993 and 1996. The population density has also increased in the earlier settlements. According to Abbott, all this overcrowding is a “time bomb.”

Of necessity, the settlements are built on marginal land. They are often in breach of several laws: land tenure (illegal occupation of the land), zoning laws and building regulations. The urban planning process which normally tries to control development cannot cope. Says Abbot, “(There is) not a good correlation between planning and the realities of urban growth.”

Dealing with some of those realities is the purpose of the Nolusapho Accessible Housing project, a concept for community-built housing using existing settlements. Nolusapho is a collaboration between the University of Cape Town Urban Management Research Team which deals with technical aspects of the concept, and the Triple Trust Organization which deals with its training aspects.

The casual observer may see informal settlements as a chaotic jumble of shelters. But the people there have invested work, money and ingenuity into their dwellings. They are neighbours and friends; they provide services to each other. Those who have had time to settle have built social networks that are important to the stability of the settlements. Those networks are worth preserving. Some of the settlements have located close to existing infrastructure, an advantage also worth preserving. Conventional new housing is sometimes delivered taking advantage of existing infrastructure, but it is not usually planned on the basis of communal ties. The resulting discomfort among the inhabitants is clear in many projects.

The low-cost construction market in South Africa is dominated by the kind of Site and Services approach seen in Canadian suburban development. The physical infrastructure of roads, water lines and sewers is laid on, houses are built and the people move into them. The technical and financial professionals who dominate this development scene in South Africa are not always comfortable with the concept of community-built housing on the existing sites. Abbott says, “On a greenfield site, [you] can do everything in a very linear, logical process. You get a blank slate. In upgrade [projects], everything is parallel: land tenure, social interaction, etc. You develop the area while people are in it.” The community housing concept “is a social development, with a major technical component.”

In situ building

The technical centrepiece of Professor Abbott’s concept is an inexpensive but sturdy house which can be constructed in situ over the existing shack. The structure forms the upper floor of the house while the occupants continue living below. They do not have to move unless they want to while their house is being built. The innovative design allows community members or occupants to do much of the work. Some of the materials from their existing shacks can be used during construction. The estimated cost of a 4.8 m x 4.8 m house is well under $4,000. And there is even some Canadian content.

The construction uses a number of new technologies. The Ecobeam is a locally invented and patented beam which is light, strong and cheap. It consists of two battens of wood separated by a zigzag of galvanized metal. The walls and foundations are formed out of sandbags. The 300-mm x 300-mm bags are made of non-woven polyester fabric, filled with sand for the walls and with cement mix for the foundations. Canadian oriented strand board, a laminated board of wood slices, is used for the floors, roof and wall cladding. The PowerLoom/LunaLoom System, a ready-made assembly of moulded and sealed electrical outlets and joints, allows residents to electrify the house without the help of an electrician.

Nolusapho anticipates that members of the community would be trained to produce the Ecobeams and build the roofing and gable end cladding. Trained members of the community would lay the foundations and assemble the house above the existing structure. Residents would complete the ground floor themselves.

The Nolusapho concept offers the community an opportunity to secure housing, but it also requires that community members do a great deal of the work — work which should benefit them far beyond the immediate good of acquiring a house. They expect the people to benefit from training in building techniques, from employment in producing beams and sandbags, from gaining business experience and from social development.

Community benefits

Indeed, the success of in-situ upgrading depends on the community participating in meaningful ways in the design and development of the project. These are the lessons which the South African team have learned from studying Brazilian examples. According to Nolusapho, “The community has to be prepared to manage the development process in partnership with the municipality.” It anticipates that “engineers, planners and social workers would be part of this community-managed planning and implementation process to advise, provide technical support and ensure the technical integrity of the development plan, the civil infrastructure and people’s housing construction process.” And while it may be a tall order for these different groups to work together, the essential aim of the project is for these combinations to take place, for the social element is as important as the engineering aspects.

Discussions with the United Nations Centre for Human Settlements, local authorities and the University of Cape Town team led to the choice of three areas for pilot projects. They are close to transport routes so that residents can walk to shopping centres and are in reach of schools, medical and community facilities. The communities have a level of civic organization in the form of residents groups. If the social component is as successful as P
rofessor Abbott’s technical solution, some of these rickety shacks on the windswept plains of Cape Town may soon turn into the homes of proud residents.

Rosalind Cairncross, P.Eng. is a consulting editor of Canadian Consulting Engineer.


Stories continue below

Print this page

Related Stories