A foreigner arriving in Peru is always surprised at the number of adobe constructions, made from sun-dried bricks of mud. From grand colonial palaces to simple field enclosures, from the crumbling pyramids of the ancient Moche civilization to the humble homes of poor farmers, these non-fired bricks are an integral part of the Peruvian landscape, particularly along the Pacific coast where it hardly ever rains.
It is estimated that 65% of Peru's rural inhabitants, and at least a third of city-dwellers, live in adobe buildings, and often in ones that have been around for a long time. Adobe construction has many advantages: it is low-cost (less than half the price of conventional bricks), the raw materials (straw and clay) are readily available, it has excellent heat and sound insulating properties, and it is easy to produce.
For some years, however, adobe has been falling out of favour with Peruvian home builders. Many new structures are being built today of clay bricks or cement blocks.
"Adobe is looked down on today in all of Peru's villages", notes Luis Zegarra Ciguero, with a touch of regret. Mr Zegarra is director of research in the engineering department of the Pontifical Catholic University of Peru, in Lima. "Bricks and concrete have become something of a status symbol. In Spanish, people say that these are 'noble' materials, while adobe is associated with poverty."
There is also a technical problem involved. In areas like the Andean Plateau that are subject to frequent earthquakes, traditional adobe houses have a tendency to collapse all too readily. In fact, a quake in 1970 destroyed some 60,000 homes, killing more than 50,000 people and injuring another 150,000. When the ground shakes, adobe bricks are likely to crack and disintegrate, which causes the walls to collapse and the roof to fall in.
With the active support of IDRC, a team of three engineers and eight technical experts at the university has found a solution to this problem. In addition to using bamboo poles to reinforce the walls, Luis Zegarra's team has discovered that the simplest and most effective way to keep the roof from collapsing is to place a solid wooden plank on top of each of the walls. The roof beams then rest directly on these planks, and the weight is evenly distributed so that the walls have a better chance of withstanding an earth tremor.
Once this technical problem had been resolved, there was still the question of persuading people to trust this "new" product. This step posed a considerable challenge, in light of the poor popular perception of adobe, which is considered an inferior material not only by potential home-buyers but also by mortgage lenders. With IDRC's assistance, a number of adobe bungalows have been built over the past few months at Piura, in the northen part of the country. The municipality offers the land at a good price, and the local credit union will advance buyers the money. For about US$5,000, a family can find modern, healthful accommodation in a home measuring 55 square metres. The total cost, which includes interior finishing, doors, windows, and bathroom, works out to approximately $100 per square metre -- a bargain, even in Peru, where the shortage of affordable housing is estimated to be at least a million units.
While the bungalows at Piura were put up by a local contractor, the system has been designed with the do-it-yourself builder in mind. "The idea is that if people can build a traditional adobe home, they will in fact be building a better home", says Gladys Villa Garcia, who is in charge of the anti-seismic building research centre at the Pontifical University. "The construction technique is very simple. We have printed up several thousand brochures showing how to do it, step by step. Some of the houses built by this method in Piura have already found takers -- and they are very happy with their purchase! With all the publicity our research has attracted, people are really becoming interested."
André Lachance is a freelance journalist in Montreal who recently travelled to Peru.
Resource Person:
Luis Zegarra Ciguero, Departamento de Ingeniería Civil, Pontífica Universidad Católica del Perú, Av. Universitaria, Cuadra 18, San Miguel, Lima, Peru. Tel: (51 1) 462 2540. Fax: (51 1) 461 1785.