By Mario Osava
RIO DE JANEIRO, Feb 24 2003 (IPS)

Engineers, architects and other professionals seem to have found new motivation to offer their skills for social and environmental projects, with leftist President Luiz Inácio Lula da Silva newly in office, backed by the Workers’ Party (PT).

Technicians and researchers are advising officials and communities in the construction of low-income housing, improvement of urban infrastructure for the handicapped and the promotion of production by small farmers.

There are some 850,000 professionals across Brazil who could volunteer their services to help resolve deficiencies in these and other areas, Wilson Lang, president of the Federal Engineering, Architecture and Agronomy Council (CONFEA), told IPS.

Some of the existing projects were developed through agreements between regional professional associations and city or state governments, but there is greater need than is being met, said Lang.

In the southern municipality of Sao José dos Campos, 100 km from Sao Paulo and home to 550,000 people, more than 8,000 low- income families were able to build their own homes through a collective, voluntary approach, known here as "mutirao".

Construction of those homes began in 1988, facilitated by the free technical assistance of a local association of engineers, in an agreement with the city government.

But CONFEA, which promoted similar projects in five other Brazilian states, is not satisfied.

So it issued a call to create a national movement of "public engineering and architectural offices" aimed at "bringing technical knowledge to the social realm," to promote inclusion and to assist in projects that create jobs and income and improve the local quality of life.

And there is growing enthusiasm among professionals, who want to put their expertise to use.

The launch of the programme coincides with the celebrations of CONFEA’s 70 years of existence.

Meanwhile, there are many engineers who are working on university research in search of less costly and environmentally friendly approaches to low-income housing and urbanisation in general.

One such expert is Francisco Casanova, who developed a model for "ecological housing", which makes use of age-old techniques – updated with today’s technology – to utilise soil as a building material.

The outcome has been homes that are very inexpensive to build but are thermally and acoustically well insulated.

The procedure developed at the engineering research centre at the Federal University of Rio de Janeiro involves bricks made from local soil, "a free raw material", using a press that can even be operated manually, Casanova told IPS.

These "raw" bricks, which do not need to be fired in a kiln, also imply great energy savings, which makes them more eco- friendly, he added.

The cement needed to build this type of "ecological home" is up to 75 percent less than is used in conventionally-built houses, depending on soil type, and construction time can be as much as 33 percent shorter.

The total savings entailed in this approach can reduce home building costs by more than half, says Casanova.

Building a 50-square-metre home in Brazil would cost around 1,400 dollars, not counting the cost of labour, which in this case could be provided by the family to live in the house, or by volunteers, he explained.

The model won an award in the Dominican Republic, where the government adopted it to build low-cost housing. Meanwhile, Casanova’s students are taking this building method to other countries of Latin America and Africa.

The same type of brick is used to construct larger homes and even mansions, whose owners and architects were convinced by their aesthetic and environmental advantages, the engineer pointed out.

The mud brick "has greater thermal inertia" than a conventional kiln-fired brick, and takes eight hours to warm up or cool down, explaining why it is better at protecting the home’s interior from outside temperature swings, Casanova said.

The housing deficit is as high as 6.0 million units in this country of 170 million people, and around two-thirds of the need is in urban areas, according to several studies.

Engineer Romildo Toledo, also of the university engineering centre, runs a similar project that places high priority on the environment, developing "eco-concrete", which uses less cement because it is substituted with industrial and agricultural waste.

The cement industry is responsible for a large share of the worldwide emissions of carbon dioxide, the leading greenhouse gas, which the scientific community generally agrees causes global warming, Toledo explains.

It is currently possible to replace up to 40 percent of the conventional cement used in constructing houses, bridges, factories and other structures, "and it could eventually reach 50 to 55 percent."

Mining waste, such as the dust created in crushing ore or rock, or ceramics, can serve as a component of "ecological concrete". Other possibilities include ashes from rice husks or sugarcane pulp, after they are burned as biomass to generate electricity.

The resistance and durability of the cement would not vary, assures Toledo.

Like the eco-bricks, the eco-cement makes use of locally available and low-cost inputs, which also saves in transporting construction materials and creates new sources of income for industry and agriculture through the sales of certain waste products.

Excerpt: