BANGKOK, 4 May 2011 (IRIN) - As a country vulnerable to the next "big one", [ http://www.irinnews.org/Report.aspx?ReportId=88693 ] people in Nepal are abuzz with an age-old, earthquake-resistant method of constructing buildings out of straw that could save lives, experts say.
"We live in Kathmandu and everyone says it is rubble in the making," said Ajaya Dixit, head of the Institute for Social and Environment Transition (ISET) in Nepal, an international organization leading in adaptive strategies for issues related to climate change and disaster risk reduction. [ http://www.i-s-e-t.org/ ] Dixit has been spearheading a pilot straw-bale project and plans to break ground on Nepal's first straw-bale building in May.
Though it may seem counter-intuitive, straw, a relatively lightweight and flexible natural material, when sealed with plaster or mud, offers a sound, waterproof structure that will bend before it breaks, said Peeranan Towashiraporn, senior project manager and earthquake expert at the Asia Disaster Preparedness Center (ADPC) in Bangkok. [ http://www.adpc.net/v2007/ ]
People will see movement in the building and be able to escape before a possible collapse. If it does collapse, people are more likely to escape from beneath straw than bricks, research shows.
An affordable option
As citizens of one of the poorest countries in South Asia, the Nepalese need any building option to be economical. As part of the pilot programme research, Dixit and his team at ISET compared the cost of constructing a 65sqm straw-bale house to that of a similar-sized, traditional concrete structure.
They found that in Kathmandu a straw-bale house would be 15 percent cheaper than concrete, while in the Terai region (southern Nepal), where the country is most fertile and straw more readily available, the cost would be 26 percent less.
Finding such cost-effective earthquake-resistant materials is vital in Nepal, Pitambar Aryal, director of the disaster management department at the Nepal Red Cross Society [ http://www.nrcs.org/home/index.php ], told IRIN. Bamboo has also been offered as an option, but to people accustomed to stone houses, it has been a hard sell, he said.
Need for materials
Michael Lawrence, a senior research fellow at the University of Bath, cautioned that to make straw-bale construction feasible, the country needed straw and lots of it, as well as mechanical baling equipment. Without this, straw-bale houses might be more expensive and less safe than expected, he said.
While straw from Nepal's agricultural industry is available, the country suffers from food insecurity because of floods, droughts and conflict.
The World Food Programme estimates 41 percent of the population are undernourished and says more than half a million people living in the far and mid-west regions are the most susceptible to agricultural problems.
Researchers are exploring alternative materials, such as lantana, a robust, drought-resistant shrub causing serious degradation in the lower forest and grassland regions, said Marcus Moench, director of ISET in Colorado.
"If we can find a productive use for [lantana] as a material for housing, using straw-bale techniques, this could provide a strong incentive for harvesting it and keeping it under control," Moench said.
And while mechanical baling equipment is not readily available in Nepal, ISET is using a locally made hand-baler modelled on equipment used in similar projects in Pakistan.
If construction materials fall into place for ISET, though, then straw-bale could be a great option for Nepal, not only because the structures are earthquake resistant, but also because straw-bale houses are easy to build, Lawrence said.
"A group of villagers can whack up a straw house much quicker than using other materials such as brick and it also requires less of a skill base," Lawrence said.
After working out the technical details, Dixit said the biggest obstacle would be convincing people accustomed to houses built from stone or mud to choose straw.
"There is a certain bias we have to overcome. People want a safe comfortable house and cement and concrete is perceived to be modern. To say, 'Hey guys, let's build out of straw,' can be very out of the blue," Dixit said.
But straw's ability to keep houses warm in cold months and cool in hot months is an added selling point.
And what about pests, rot and fire? If the straw is dry and bales are properly compressed, then sealed with mud or plaster, tests have shown straw houses are just as resistant to these hazards as traditional ones, if not more so.