Accra, Ghana — In Ghana, as in many African countries, concrete - with its dependence on imported inputs - is considered indispensable for building. Yet an excellent, cheap and local alternative is readily available in the form of laterite - the material of choice for unmetalled roads all over the continent. One architect in Ghana is trying to blaze a trail for a highly sustainable laterite brick technology. Alero Olympio argues that making use of the accumulated knowledge on the best ways to build in tropical climates can save her clients money, reduce dependence on strained public services and cut energy consumption. Her primary goal is to explore natural materials in Africa and develop the skills to use them in the hope of developing a contemporary African architecture that is sustainable. Ofeibea Quist-Arcton met her in Accra, Ghana.
What does sustainable architecture mean in the Ghanaian context?
Essentially what Im working with are natural materials. So, for instance, I use stone. I also make thermal bricks which are low-energy products and make a very good insulant, keeping the house cool.
The bricks that we make are made from laterite, which is the main red soil material that you get almost all over Africa and indeed, in India and parts of southeast Asia.
We also do things like incorporating rain water recovery systems in our buildings, in other words we make sure that in the design of the building, we allow for rain water to be collected easily so that it can be re-used for washing and watering the garden and so on.
We use low-flush toilets, so that youre not flushing nine litres of fresh drinking water down your toilet. We also orientate your building, so that you have the prevailing winds - from the southwest - keeping your house cross-ventilated.
We use very high ceilings and big, big windows. Theres a lot of natural light. And we try to discourage air conditioners.
We also build in the possibility for solar energy - solar water-heating, solar lighting, and biogas systems for processing human waste. All of these are encouraged and we do make sure that they are designed into our houses.
Practically, can the average Ghanaian afford a house like the one youre describing? What sort of price are we talking about? The finished product might be great, but is the construction affordable?
Its definitely affordable. Look, the interesting thing about Ghanaians is they all have very grand ideas. And certainly the middle classes in Ghana are paying in excess of $150-200,000 dollars for a house. Certainly, youre paying for space. Youre not necessarily paying for good design. So, what I try to encourage is to be able to use the environment, to use the outside space, for instance, which is practically free .
Looking at the architecture in Ghana, I see that outside spaces are not valued. What they try to do is build on as much of the site as possible. Certainly it is possible to build a house for $40-60,000 and meet all the requirements for ecological living and have solar power and be independent from most of the utility services in Ghana. That is the aim that we hope to achieve while were working here.
Is it catching on? Environmentally, ecologically sound and sustainable housing with solar power and so on?
Is it catching on? That is a good question. Ive actually been working at this since 1987. I first started with doing a self-build house, so that houses were affordable. I supplied the materials and the technical expertise and you built your house yourself. Of course, I have to make money myself and I realised that was going to be very difficult for me.
The Ministry of Works and Housing was very interested in my methods, but they couldn't pay me.
I also found that building with earth and stone began to be linked with "low-cost", because I professed to be able to build a house with less than 30 thousand dollars. And I believe that if you want to transform any attitudes in the bourgeois, materialistic society that Ghana is becoming, you actually have to start from the top. You have to go to rich people and get rich people to buy into it. And, if you do, then poorer people will also aspire to it.
So, I came back again in 1995 and I decided to build expensive, luxury, ecological houses which is what Im doing now. And I feel that, in that way, I will be able to encourage people with less money to also aspire to the same kind of life.
So have wealthy Ghanaians bought into ecologically built houses, would you say?
Yes, they have. Im not a huge builder, so Ive built about 12 houses so far and, yes, I have managed to sell them with absolutely no problem. Im restricted only by the number of people I work with. Im only one architect and I cant build more than four houses a year. And I dont intend to build more than four houses a year. I think that would compromise the architecture. The architecture is very tropical and the aesthetic is tropical and African. I try to make sure that Im not using any European classical symbols -
- Such as?
Ionic columns and Italian capitals and bases to the friezes and cornices and so on. I tried to make sure that the material provides the beauty of the building. Most of the buildings are courtyard buildings, based on the Ashanti compound.
If you go anywhere in the world, you will find that most tropical buildings actually look the same. And theres a good, good reason for it. The depth of the building ensures cross-ventilation. A steep roof, a big overhang, the pavilion 'Louisiana plantation house' type of architecture. There are no myths as to why those work better. The old Ridge buildings that were built in the colonial days are invariably cooler buildings, like Legon University (in Accra). Indeed, its one of my favourite buildings in Ghana.
That is the type of architecture I like to emulate and most of my buildings have that kind of imagery.
Now lets talk practically. Your bricks are handmade arent they? As you say, they are red laterite, almost shot with a bit of grey, so its an unusual, but rather lovely rich terracotta colour.
Laterite is an extraordinary material, actually, and its everywhere in Ghana. And it has been dug up. The road contractors use it and most contractors and civil engineers know the properties of that soil. It has a red oxide in it, iron oxide, that makes it red. It has very good, natural cementitious properties. If you dig laterite out of the ground and you leave it in a pile and you come back six months later, itll be hard. Youll need a pick axe to get through it.
So it sets quite naturally, so we are blessed. Its gold for the construction industry and it makes very good roads. Nobody seems to really use it for general construction here, other than for road building.
Cement being the preferred material?
Yes, yes. Cement is the preferred material. Of course, cement has to be milled from clinker which is imported from Europe, and I think thats unfortunate. Our idea is to reduce the amount of imported material. So, we use laterite. It gives us a very, very dense brick that has very good thermal properties. It is a cool brick, more like a clay brick. We dont fire it, unlike clay bricks. Firing requires energy and energy is expensive.
Its compressed at very, very high pressure with a hydraulic manual press. So obviously we cant make as many bricks as a factory. But we can make two thousand bricks a day with my present capacity and that suits us well. You use about 20 thousand bricks per big house. That means it takes us about ten days to make enough bricks to build one house. They are cured and the longer they are cured the stronger they are.
We can also increase or decrease the strength of our compaction pressure to give us either a stronger or weaker block. They are cost effective. You dont have to plaster them. You dont have to paint them if you like the (natural) colour. Of course, on occasion, we do plaster and paint depending on what our client wishes.
They are difficult to lay, because they are stronger than the mortar. In Ghana, the concrete blocks used here are weaker than the mortar, so you tend to find that in old buildings the mortar is still retained and the sandcrete block has some erosion on it. With the laterite brick, its the reverse. You use very, very little mortar and because of that you have to have very good brick layers and very good workmanship. Thats something thats difficult to get in Ghana and thats part of my technology transfer.
Where do these techniques come from? You studied at Edinburgh and I believe its Asia you go to for your inspiration?
Its certainly not a new technique. Its been around for a long time. In fact, even at the [Kwame Nkrumah] University of Science and Technology [in Kumasi, Ghana], they have been familiar with the technology. Its actually called stabilised soil construction. I studied it in India and in Mexico where its very common.
The government in India has a huge budget to explore and progress this technique in stabilised soil construction. They build libraries, public buildings, museums, courthouses with this brick. Thats exactly what I hope to get Ghana into in the next five years.