Traditional homes more sustainable than modern houses: expert

Traditional homes made of locally sourced materials maybe more sustainable than modern houses built from industrial building materials that are often scarce and expensive, according to an Indian-origin scientist.

Everyone wants a house to live in, and more and more, people around the world want the kinds of houses seen in Europe and North America, rather than those they grew up with, said Khanjan Mehta, assistant professor of engineering design, at Pennsylvania State University.

"What makes a good house? Is it wood, steel, concrete or bamboo?" Mehta said. "It all depends on the context. In some places steel and concrete are perfect, while straw bales and bamboo are optimal in other places," Mehta said.

"We should be evaluating what is economically, socially and environmentally sustainable at the necessary scale in a given location," he said.

Mehta acknowledges that often, indigenous housing is temporary housing. Seasonally or yearly it needs to be repaired or replaced due to weather and use damage.

However, switching to permanent concrete-block construction is not necessarily the answer. In many places in Africa and South East Asia, cement - the major component of concrete - is scarce and or expensive.

"In Zambia, I was in a small village, and the concrete walls moved if someone leaned on them," Mehta said.

He explained that if cement is expensive, workers will use the least amount of cement they can and instead add more easily accessible sand to the concrete.

This mix, however, does not have the strength or longevity of properly mixed concrete.

"In Western Kenya, on the shores of Lake Victoria, all the  houses now have tin roofs. Ten years back, no one had a tin roof and now tin roofs are called by the name of the company that makes them," said Mehta.

This branding reflects the fact that there is only one manufacturer of tin roofs, which creates a monopoly that could lead to price manipulation.

According to Mehta, one project, a windmill farm, failed because of dependence on a single supplier of steel. The material became so expensive, the windmills could not be built.

"What we need to find are materials that are economical, environmentally friendly and socially acceptable. The materials also need to be scalable," said Mehta.

For example, one approach uses locally thrown pottery vessels as the layer between a subroof and the final roof. The pots are all uniform, easily manufactured and inexpensive.

Their installation on the roof provides an air space as insulation so that other, more expensive, materials are not needed.

"People see western stuff as better, more modern and therefore they think it is good. Traditional homes can be just as cool, and maybe more sustainable," said Mehta.