Development & Aid, Environment, Tierramerica

Uruguayans Return to Mud and Straw

CIUDAD DE LA COSTA, Uruguay, Feb 22 2010 (IPS) - Soil and straw from the Uruguayan plains were the raw material for the homes of the indigenous peoples over the millennia, and they are in demand again.

There are more and more Uruguayans who want to build ecological homes. The problem is that there is hardly any market or specialized labor for what is known as “bio-building.”

Homes made from earth mean energy savings and contribute to fighting climate change, because their very construction emits less greenhouse gas than the usual commercial construction techniques.

Inside these homes there is a pleasant environment, insulated from extreme temperatures and humidity. But perhaps most important is that they allow people to build their homes themselves and to produce the necessary components – making these structures more economical.

All told – with labor costs, architectural consulting and other expenses -, an earth home in Uruguay costs between 500 and 600 dollars per square meter, while a standard cinder-block house costs almost twice as much, at 900 to 1,000 dollars per square meter.

It was once common in the countryside of this small South American country for houses to be built with the materials provided by nature: dirt, wood, straw. Those techniques, which are now known as bio-construction or bio-building, were passed down from generation to generation, and even today there are a few who maintain that tradition.

In the 1990s, a group of architects began studying the use of earth in construction, at the same time the ideas and techniques were being incorporated into the curriculum at the University of the Republic's school of architecture.

This meant that the approach could be replicated in different parts of the country – but they were isolated experiences, and the government showed little interest in supporting it.

Over the past 15 years, around 100 of these bio-homes have been built with the participation of the architects, and another 100 by the owners themselves.

The demand for environmentally sustainable construction techniques is on the rise, but there are no policies to guide it, no market for production and sales of eco-materials, and few construction workers familiar with the techniques.

Those are the basic elements needed to promote alternative construction, according to architect Rosario Etchebarne, an expert in bio-building and professor and researcher at the University's school of architecture.

“There is great demand from the population, and many people are motivated to experiment, but the authorities remain hesitant, because we are lacking technical standards for the construction processes and they fear the experimental approach,” she told Tierramérica.

Etchebarne explained the three most used techniques: adobe, which is a brick that is not baked; the compressed earth block (CEB), which is made by a mechanical press; and “fajina”, a wood frame with soil stabilized with straw and other components.

“Bio-construction incorporates many concepts of sustainability. The basis of everything is that there is energy savings,” Etchebarne said.

“We would be making a contribution to mitigating climate change, because we would not be emitting any carbon dioxide into the environment, because the cement used is minimal,” she added.

One of the most interesting experiences recently in earth construction is Guyunusa, a housing cooperative in Ciudad de la Costa, in the southern Uruguayan department of Canelones, on the River Plate (Río de la Plata). The 10 homes were built using mud and paid for with a loan from the Ministry of Housing.

“We chose this type of construction because we wanted cheaper and healthier housing. We researched different techniques and concluded that a mud home was healthier and better insulated, more economical and within everyone's means,” Silvana Delfino, a member of the cooperative, told Tierramérica.

“It's nothing new: human beings have lived in earth homes here and in other parts of the world,” she added.

The Guyunusa housing complex also includes an ecological sanitation system. It is located in an area that is not connected to the sewage network, so the cooperative created its own, with financing from the United Nations Development Program (UNDP).

According to Delfino, the idea behind the cooperative is “to show that with little money we can have decent housing that respects the environment.”

In the outskirts of Montevideo, in the self-managed Comunidad del Sur and La Wayra, several families built their ecological homes with the help of German architect Heiner Peters, who visited Uruguay and shared his expertise.

This approach has also been used for building summer homes near the sea, or large homes on rural estates.

“There is no great mystery with this type of construction. It used to be that people settled in a place and built their homes with what they found around them. The problem is, perhaps, that we have unlearned some things,” Hugo Costa, who lives in La Wayra, told Tierramérica.