Elsa Zaldívar

2008 Laureate, Applied Technology
Paraguay, Born 1960


Project Goal

Combine loofah and plastic waste to make low-cost housing

Location: Paraguay

Recyclable Homes

In the poverty-stricken countryside of Paraguay, a landlocked country in the heart of South America, an innovative social activist has found a new use for an old vegetable. Elsa Zaldívar, whose longstanding commitment to helping the poor while protecting the environment has won her deep respect in her native land, has found a way to mix loofah — a cucumber-like vegetable that is dried to yield a scratchy sponge for use as an abrasive skin scrubber — with other vegetable matter like husks from corn and caranday palm trees, along with recycled plastic, to form strong, lightweight panels. These can be used to create furniture and construct houses, insulating them from temperature and noise. About 300,000 Paraguayan families do not have adequate housing.

Small Steps, Big Benefits
Elsa Zaldívar was born in Asunción, the nation’s capital, in 1960, during the repressive 35-year rule of President Alfredo Stroessner. Her mother was an entertainer and her father a committed political leader fiercely opposed to the military dictatorship. Zaldívar inherited their passion for change and became involved in social programmes, working with poor people in her neighbourhood. She took a degree in communications and, from 1992, ran a rural development programme in Caaguazú, a region that had experienced severe deforestation for more than four decades. Her work quickly showed her how making a simple change can transform people’s lives.

“We carried out a project with women to construct toilets, and we built stoves for them to cook on,” she explains. “It was impressive how these simple acts changed the women’s lives. They told me: ‘Now we feel like we’re people with dignity.’ That’s the result of simply having a bathroom inside or close to the house rather than 100 metres away, and being able to cook on a stove rather than stooped over a fire on the ground.”

The Sponge Solution
Zaldívar decided that the most effective way to improve the lives of rural women was by increasing their earning capacity. The area’s economy had declined with the collapse of cotton and increasing cultivation of soya, an environmentally disastrous crop that had left soils contaminated and forced families off the land, leaving them without employment. Zaldívar took an interest in loofah, a plant that grows easily in the region, but which had fallen out of favour. She persuaded local women in Caaguazú to consider it as a means of generating income.

When harvested before it completely ripens, loofah can be eaten. But Zaldívar’s women let the plant ripen and dry out, then process it until only a fibrous sponge remained. Their hard work, along with the ecological methods they used and the quality of the fibre they produced, gave the product a competitive advantage over plantation-grown loofahs from China and other countries. The women organized themselves in a cooperative and sold their loofah sponges as cosmetic products. They used loofah to manufacture mats, slippers, insoles and a variety of other products that were exported to markets as far away as Europe. The women’s earnings grew, and the successful enterprise drew praise from environmentalists and others. Eventually it even won the respect of the local men who had initially laughed at the project as a women’s idea that had no chance of succeeding.

Zaldívar wrote a manual about growing loofah to spread the word to other regions. She was awarded an Ashoka Fellowship in 2001 to continue her efforts to empower rural women to make products from loofah products and to set up a micro-enterprise.

Turning Waste into Homes

Yet Zaldívar was not fully satisfied with the cooperative’s success. Even with the women’s efforts to grow the high-standard vegetables, roughly one-third of the loofahs they cultivated were of inferior quality and could not be exported. And another 30 per cent of the sponge material destined for the finished products was trimmed off during manufacture. Determined to find a market for the loofah waste, Zaldívar teamed up with Pedro Padrós, an industrial engineer, to search for a way to use the vegetable material to construct inexpensive panels for walls and roofing for building houses. She had realized that if the first step to improving the lives of the poor was increasing their income, the next was to help them find decent housing, which would dramatically raise their living standards. Zaldívar was highly enthusiastic. But, disappointingly, initial efforts to mix loofah with different types of glues did not produce the desired result, mainly because of the high costs involved.

Then Padrós got the idea of using plastic waste with the loofah. He invented a machine that melted a mixture of three types of recycled plastic and combined the resulting liquid with loofah and other vegetable fibres, such as cotton netting and chopped corn husks. After hundreds of trials, the results began to produce a working product. With help from Paraguay’s environment ministry, Base ECTA (a non-profit organization headed by Zaldívar) obtained a grant from the Inter-American Development Bank to construct the prototype of a machine to produce the panels.

Combining a melting unit, mixer, extruder and cutting unit, the machine can produce — in an hour — a half-metre-wide panel 120 metres long. Depending on the exact mix of plastics and fibres, as well as the thickness of the panel, the composite can have varying amounts of flexibility, weight and insulating qualities, making it adaptable to a variety of construction needs. Colouring can be included in the panel’s plastic mix at the time of fabrication, so there is no need to paint the walls after construction, saving homeowners time and money. Padrós says a panel of even greater strength can be created by using a honeycomb or earthen filler, as well as vegetable matter, to create a sandwich of two panels.

Better Buildings
The composite panels are easier to handle than lumber or brick, and much better than conventional materials in an earthquake or other natural catastrophe. Combined with special metal connectors, “it will bend but not break”, Padrós says. And if a house does collapse, he says, someone is much more likely to survive if the walls are lighter in weight than conventional materials. And using the panels will help spare the nation’s forests. “Because we’re using fibres that are completely renewable, we can stop using lumber for construction. That’s very important in Paraguay because we’ve already reduced our original forest to less than ten per cent of Paraguay’s territory,” Zaldívar points out. “We’re running out of trees.”

As Padrós has refined the design of the panels, improvements have brought the cost down. The panels initially cost about US$6 per square metre to produce, but the cost has already dropped to less than half that figure, making it competitive with existing construction materials, such as wood. Zaldívar predicts the price will continue to fall as experiments continue. She is also involved in discussions with several companies interested in using the panels commercially, but her main aim is to make the material available at low cost to those who need them most.

By supplementing the panels with other locally obtained materials such as bamboo and adobe, Zaldívar believes rural families should be able to build their own simple house in just three to four days. Even urban residents, who often have access to subsidized credit and other government assistance, will be able to use the panels in constructing decent housing.

Thinking Through Every Step

The project’s success derives from the unique combination of Padrós’ engineering skills with Zaldívar’s genius in creating an integrated system of cultivation, recycling, production and distribution. In addition to the loofah producers, Zaldívar is working with recyclers in urban areas in order to guarantee a flow of appropriate plastic, and with groups of women to provide the tonnes of corn and palm husks, for example, that will be needed — all materials that would otherwise end up in landfills.

Padrós says the panels are designed so that they will not generate any waste — should they wear out or break, they can be ground up and recycled into new panels. The process could be repeated several times until the composite becomes too rich in vegetable fibres, but Padrós says the mixture can then be used as a high-energy fuel. That means the recycled plastics used in the initial mix must be carefully selected to insure that they can be burned without producing toxic fumes.

Innovation Leads to Impact
Paraguayans are greeting news of the panels with excitement. Gustavo Candia, a Paraguayan consultant on good government and poverty reduction for the German development organization Gesellschaft für Technische Zusammenarbeit (GTZ), says that Zaldívar’s initiative allows “primary producers to participate in adding value to their products”, a distinct achievement for poor rural farmers. Zaldívar’s reputation as an innovator is well deserved, he believes. “With this project, Elsa reaffirms that with persistence and reflection, you can create socio-economic impact in sectors that have generally been excluded from progress,” Candia said.

As Zaldívar and Padrós finish testing the improved panel-making machine, the Rolex Award will finance a promotion centre near Asunción and the construction of three model houses where the panels’ versatility will be displayed for both urban and rural audiences, as well as funding the production of a video that will be used to describe the project to people interested in using similar techniques in other countries.

Zaldívar’s initial focus for providing low-cost housing remains Paraguay’s deforested countryside. “We want to find sustainable housing alternatives for the poor, while also discovering new markets for their agricultural products, particularly the loofah. This is a perfect combination,” she says.

Paul Jeffrey

Other 2008 Laureates