By David South, Development Challenges, South-South Solutions
As the population around the world’s cities grows, and slums grow larger and more prevalent, the urgent need for affordable and decent housing becomes more pressing. The world’s megacities – like Buenos Aires, Argentina, where more than 13 million live in the metropolitan region – have to find a way to provide housing that is both cheap and does the minimum possible amount of harm to the environment.
About one-third of the world’s urban dwellers live in slums, and the United Nations estimates that the number of people living in such conditions will double by 2030 as a result of rapid urbanization in developing countries. Latin America is already the most urbanized region in the developing world.
“Throughout Latin America you have economies that are growing and doing well, but the way the economies are growing is actually generating more shanty towns,” said Erik Vittrup, senior adviser on Latin America and the Caribbean for the U.N. Human Settlements Program. “It’s a growth that is just generating wealth for those who (already) have it.”
How well people dwell is integral to their mental and physical health. Most squatters and slum dwellers live in makeshift homes made from whatever they can get their hands on. These dwellings are usually unsafe and vulnerable to fire, floods, and earthquakes.
But across the South, initiatives are proving it is possible to build good quality homes for the poor while avoiding burdening them with debt. Pioneering ways are being developed for the poor to build their own high-quality houses using recycled materials and environmentally friendly products.
In Colombia , Alejandro Salazar, a chemical engineer, professor at the Universidad del Valle (http://www.univalle.edu.co/english/) and innovator running several companies pioneering new building technologies using recycled waste, is building high-quality, inexpensive houses for the poor. By combining free building materials recovered from waste, a government grant and the voluntary labour of the homeowners, Salazar’s company is able to build homes for the poor that don’t leave them with ongoing bank debt from mortgages.
Based in Cali, Colombia (http://gosouthamerica.about.com/od/cali/p/Cali.htm), his companies Ecoingenieria (product and material research and development), Ecomat SA (production of eco-materials using industrial waste and construction rubble), Constructora Paez, (social housing construction using eco-products) and Wassh SA (environmental management and transformation of dangerous solid waste into non-dangerous materials), are focused on pioneering new technologies for housing.
“Our company uses two basic technologies,” said Salazar. “The production of eco-materials from solid waste and demolition waste, and the implementation of an agile building system, which does not require skilled labour and is hand-transportable. All the pieces are produced in a prefabrication plant that uses the eco-materials.”
Salazar has found a way to provide homes quicker than existing NGOs – Popular Housing Organizations (OPV), as they are called – established to address homelessness in Colombia. The homeless poor are caught in a Catch-22: they need to have a formal job to receive homebuilding assistance from the government, and they usually can not save up enough money for a down payment on the home.
Salazar’s solution is to take the maximum grant given by the central government, which is US $4,730, and combine it with the recycled building materials and homeowners’ own labour. He says this allows a house to be built for roughly half the price of a similarly sized one that uses conventional materials: the eco-materials house costs around US $ 6,590, compared to US $12,000 using conventional materials. Land is often either donated by the municipality or the family already owns it. And in Salazar’s experience, the whole family chips in with the building: husbands, sons, brothers, fathers, wives.
The training takes just three days on eco-materials and a day in construction techniques for house building.
“To date, we have built with this method 306 houses,” said Salazar. “For the coming year, we expect to deliver around 500 houses or more. To build a house, after acquiring the land, we need three people working eight hours a day to build it in four weeks – all under the supervision of a workforce teacher and the supervision of an engineer or architect.
“The houses are designed by architects with the participation of the community or families. They do some workshops and the design conforms to their vision and expectation. In Colombia, there is an earthquake resistance code which is binding in law and provides detailed specifications of the materials, foundations, structure and roof.”
The pre-fabricated building materials are made from recovered waste from a wide variety of sources: ceramic red brick, coarse ash and fly ash, slag from steel, copper slag, porcelain insulators used for electrical power lines, nickel slag, sludge from sugar and alcohol plants and water treatment plants.
“The raw materials we use are industrial solid waste and demolition waste. It costs the industry a lot to throw away this waste,” Salazar said.
He said the biggest obstacle to the new homes is psychological: many people initially “tend to reject at first-hand the technology.”
“When visiting the factory and then visiting the homes – or model homes – they then compare it with a traditional house, and realize that the best eco-homes when finished meet the standards of Colombian earthquake resistance and are also cheaper,” he said.
Compared to using conventional building materials, the eco-materials reduce the cost of a new home. And the company still makes a profit from it!
In Paraguay, Elsa Zaldivar is using recycled plastic, cotton netting, corn husks, and loofah sponges (http://en.wikipedia.org/wiki/Luffa) to make cheap, lightweight construction panels for housing. This has a double benefit: it makes for cheap housing and it is good for the environment.
“That’s very important in Paraguay,” said Zaldivar, “because we’ve already reduced our original forest to less than 10 percent of the national territory.”
Zaldivar got her experience working with people in the impoverished area of Caaguazú, where in the past she helped with the building of toilets and making stoves. She found that involving local people in this work made a huge difference: “They told me: ‘Now we feel like we’re people with dignity.’”
She encourages local women to grow loofah – a plant that once flourished but was being ignored. While the fruit is edible she was more interested in the crusty sponge that is left over when the plant is dried. The women started a cooperative selling loofah sponges, mats and slippers. But there was a lot of waste in the process, with a third not suitable for export. She then came up with the idea to use the loofahs for wall and roof panels for cheap housing.
Along with industrial engineer Pedro Padros, she developed a way to combine loofah with plastic waste. Padros invented a machine to melt the recycled plastic and mix the molten plastic with loofah, vegetable fibres and chopped corn husks. It has produced a building panel that is lighter and easier to move around than lumber or brick. With a grant from the Inter-American Development Bank, design improvements have been made and the cost-per-panel brought down from US $6 per square meter. It is now competitive with the cost of wood panels. The great thing about the panels is that they can be recycled again when they wear out, completing the cycle.
“To have a decent home liberates people,” said Zaldivar.
Published: January 2009
Resources
- Cradle to Cradle: Remaking the Way We Make Things: This radical concept is about how products, can be used, recycled, and used again without losing any material quality—in cradle to cradle cycles. Website: http://www.mcdonough.com/cradle_to_cradle.htm
- Builders Without Borders: Is an international network of ecological builders who advocate the use of straw, earth and other local, affordable materials in construction. Website: http://builderswithoutborders.org/
- World Hands Project: An NGO specialising in simple building techniques for the poor. Website: www.worldhandsproject.org
- CIDEM and Ecosur specialise in building low-cost community housing using eco-materials. They have projects around the world and are based in Cuba. Website: http://www.ecosur.org
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