Harare needs to see tens of thousands of new homes built as soon as possible simply to satisfy existing demand by people already living and working in the city, let alone the new families that will arise as children reach adulthood and the continuing movement of rural people into the capital. So the news that the city council is finally examining building codes to see what can be done to make these houses more affordable is welcome. But the Model Building By-laws already in existence allow a great variety of building materials and technology, although not all are accepted within local plans. The by-laws can easily be amended to incorporate new technologies, since they set standards for each type of material to ensure structures are sound rather than prescribe materials.
The critical problem is a lack of imagination. For some reason a “real house” in Zimbabwe is regarded as a box built with industrial bricks under a heavy high-pitched roof designed to allow deep falls of snow to slide off. English suburban architecture of the early 20th century is not necessarily the obvious standard for anyone’s building preferences, let alone those of Zimbabweans.
What is worrying is the council not showing much imagination. We are told that they are considering allowing burnt farm bricks for internal walls. If this is the extent of their daring we are in trouble. The by-laws allow such bricks for entire structures, and lay down standards for burned-lime mortars rather than cement mixes. This is fortunate considering the growing number of buildings in Harare are more than 100-years-old that were built with hand-made bricks fixed with lime mortar.
Archaeologists are continually digging up “farm bricks” made and burned thousands of years ago, and still sound. There are buildings in Britain, almost 1 000-years-old, built of Roman bricks made 2 000 years ago.
These are not modern industrial products but hand-made “farm bricks”.
What is needed with hand-made bricks, as well as many other technologies both new and old, are simple and easy tests to ensure that the products meet set standards. These should be possible to devise and such standards, where they do not exist, need to be created by the Standards Association of Zimbabwe. In some cases there are standards, but fancy equipment is needed. What is wanted are simple tests that a buyer or building inspector can apply on site.
Packed earth walls are another old technology. There are adobe walls and buildings hundreds of years old in Spain and Mexico and still sound. Someone got the mix right. There is a tendency for people to go for all out on pure earth, although experiments show that modest additions of cement make a lot of difference.
It is here that practical standards and tests need to be in place.
Roofing is quite often a very expensive addition to a house. Yet in Zimbabwe we only have to cope with rain, so the roof has to be leakproof, the occasional storm, so it needs to be firmly fixed, and a very occasional hailstorm, so it has to be adequately pitched so the hailstones slide off. Many roofs are over-engineered and so over-priced for these simple needs.
It is this need to get back to basics. Solid walls, adequate roofs, decent windows and doors. And the whole thing to last a couple of centuries with modest maintenance. Different technologies can be developed for each need and it should be possible for a house owner and the builder to mix and match technologies, such as adobe walls with an aluminium roof.
The city council’s building experts need to consult widely and the civil engineering profession needs to think through the problems. We cannot see why existing technologies already developed in history and in modern times from around the world cannot be examined and adapted for Zimbabwean needs, and then clear standards, enforced through easy and cheap tests, are laid down.