Mud's low cost and malleability makes it an ideal building material. But its use can be popularised only if such drawbacks as its susceptibility to moisture is overcome and misconceptions …

Ramming in earth between two r (Credit: Anil Agarwal /CSE)MUD IS a versatile building material that has been used to make some extraordinary architectural marvels -- from 1,000-year-old ksars (forts) in Morocco and 6,000-year-old arches, vaults and domes in the Nile Valley to multi-storeyed houses of adobe, sun-baked bricks of mud and straw, which is the traditional building material throughout much of Latin America.

But what gives the material so much potential importance in India, with its large population of homeless and ill-housed people, is its cheapness and widespread availability. Considering the scarcity and high cost of conventional building materials such as brick, cement and steel, one way to solve the country's severe housing shortage of an estimated 40 million units by 2000, is to switch to mud.

Mud has other inherent advantages: It is extremely malleable and offers better insulation than steel-and-concrete structures, it decentralises the construction process because it utilises local material and technology and thereby obviates the need for a contractor, and it costs much less to maintain mud buildings.

As Delhi architect Revathi Kamath puts it, "The handcrafting of buildings using mud is specially relevant to the Indian situation, where labour is abundant and where people possess the requisite skills for building with simple materials."

But there are problems associated with mud as a raw material for houses and the most serious is its vulnerability to water. Mud buildings have weathered best in extremely dry climates, such as that in Saharan Africa or Ladakh. Mud has a low tensile strength and comes apart easily, which makes mud roofs difficult to fashion and mud walls susceptible to rodents and thieves.

The Building Centre in Delhi has worked on the problem of mud and developed a technology to give the exterior facing of mud blocks a veneer of stone, cement or tile. This not only waterproofs the mud block but also makes it more attractive without losing any of the advantages of mud.

Mud's declining use in India does not relate as much to its properties as to the perception that a house is more than just a shelter. Most Indians consider a house an appreciating asset and a long-lasting investment and so even the poor dream of a brick-and-mortar home. If Indians are to accept the use of mud in house construction, they must be shown it can be made to last longer and at costs they can afford.

A crucial element in mud housing is the roof. Traditionally, mud structures have a high plinth to prevent water-logging and a sloping thatch or tile roof that extends sufficiently to protect the walls from rain. In many parts of the world, including India, the roof is supported by wooden beams and it is made of thatch or bamboo matting with mud plastered on it. In parts of Karnataka, Maharashtra, Andhra Pradesh and Tamil Nadu, the roofs of traditional houses have mud sandwiched between mud-and-timber layers. However, both methods have the inherent disadvantage of being vulnerable to water.

Mud-building can become a more attractive technology only if appropriate roofing material is developed, but very little has been done in this regard.

In recent years, there has been a revived interest in mud as a building material, says S K Sharma, executive director of the Indian National Trust for Art and Cultural Heritage (INTACH) and former chairman and director of the Housing and Urban Development Corporation (HUDCO). This, he explained, is mainly because of a shortage of conventional building materials and of finances. It was under Sharma's initiative that HUDCO sponsored the first international conference on mud architecture in 1987 at Thiruvananthapuram.

Contrary to what most people think, mud structures do not deteriorate rapidly provided they are properly maintained. Part of mud's poor reputation is because long-established mud-building techniques have been forgotten or ignored. Though people have been building mud houses for thousands of years, the technology is still not sufficiently developed or widely known.

"It only requires a simple process to upgrade mud to a high-performance building material," says Shrashtant Patara, an architect at the Society for Development Alternatives (DA), a Delhi-based organisation working on alternate technologies for sustainable growth. He noted that the development of stabilisation techniques such as adding cement to mud has done away with many drawbacks associated with mud-building. Stabilised mud blocks are also less susceptible to termites and rodents.

Explaining mud-building's cost-effectiveness, Patara noted that conventional brick construction can cost as much as Rs 1,614/sq m (Rs 150/sq ft), a mud house with modern inputs costs as little as Rs 215/sq m (Rs 20/sq ft). V Suresh, who is director of corporate planning at HUDCO, pointed out cost effectiveness and energy efficiency can be achieved in conventional construction by substituting mud blocks for burnt bricks. "Conventional brick buildings," said Suresh, "use up energy even before they come into existence. A house with 100 sq m area consumes 7.5 tonnes of fuelwood just to fire the bricks." A significant problem plaguing housing institutions, architects and building designers is how to make mud an acceptable building material. In some parts of the world, the wealthy have opted for mud-building, possibly nurturing romantic notions of such architecture as an art form. In doing so, they have displaced the poor who are traditional users of mud in building their houses. In Albuquerque, New Mexico, rich Americans have built adobe houses with all kinds of luxurious amenities, but in stark contrast, the state's Pueblo Indians, whose traditional mud houses of three to five-storeys are world famous, now live mainly in motor trailers. In fact, though many American Indians would like to revert to their traditional mud-building, they can't afford it.

India has a rich tradition in mud architecture and more than 65 million of about 118 million houses in the country are made of mud. For instance, in Kerala, houses are often built with mud and laterite blocks, with tiled roofs on coconut timber rafters and purlins (horizontal beams). HUDCO and the Kerala government have jointly financed the construction of more than 1.4 lakh mud houses in the state, 70 per cent of them in rural areas.

In Karnataka, technology developed by Application of Science and Technology for Rural Areas (ASTRA) in Bangalore (see box) and financing from the Karnataka Housing Board (KHB) inspired the mud-building mania that gripped the state in the late 1980s. This was the period when middle- and high-income families and some institutions opted to build using stabilised mud blocks, but their mud houses are showing signs of rapid deterioration (see box).

The state governments of Nagaland and Jammu and Kashmir have also promoted the use of stabilised mud blocks in a big way. Nagaland's rural development has undertaken a major programme in training people in mud-building technology, primarily because burnt brick is expensive and the local soil is ideal for mud blocks. In Andhra Pradesh and Gujarat too, the state housing boards and HUDCO have been putting up mud buildings.

Sales of mud block presses to non-governmental organisations have been increasing steadily in Orissa, Andhra Pradesh, Karnataka, Gujarat and Tamil Nadu, but they have not proved popular in Maharashtra and Madhya Pradesh because the black soil in these states is unsuitable for the making of quality mud blocks.

For the last three decades, British-born architect Laurie Baker has been promoting low-cost building technology in India. The Laurie Baker Mud Foundation was established at Trichur in Kerala in 1989, primarily to popularise and conduct studies in mud architecture.

DA's shelter group has also been working on a number of appropriate building systems using compressed earth blocks. In 1988, DA even opted to build its headquarters with this material with a Rs 5 lakh grant from HUDCO. "This was one of the first mud structures to be approved by the Delhi Administration, as per their building codes," said architect Aromar Revi, who is director of The Action Research Unit (see box).

Since 1985, DA has also designed and built houses in Badaun in UP, a futurology centre at Sri Venkateswara University in Tirupati, and in Delhi, an exhibition gallery at the Indira Gandhi National Centre for Arts, which boasts of the largest mud dome ever built, the auditorium of Ansal's School of Architecture and a research centre at the Indian Institute of Technology.

Agencies promoting mud
HUDCO, the apex body of the country's building sector, is under the Ministry of Urban Development. HUDCO has set up a nationwide network of about 105 nirmiti kendras (building centres) to disseminate appropriate building technology, including mud architecture. The first of the centres, which received Rs 1.55 crore in as grants during 1991-92, was started in 1985 at Kollam, Kerala.

Besides promoting mud-building technology for housing, the centres manufacture stabilised mud blocks with a 5 per cent cement content. The blocks, made with ASTRA-designed presses, can withstand pressures of upto 45 kg per sq cm -- the minimum is 30 kg per sq cm. The blocks cost 90 paise each -- about half the cost of a burnt brick of similar size. The Kollam nirmiti kendra also trains artisans and rural youth in building techniques.

In a bid to promote the use of stabilised mud blocks, HUDCO offers a 50 per cent subsidy on block-making machines for professional and educational institutions and 25 per cent to housing agencies and building centres.

But can mud-building technology be disseminated effectively by a centralised agency such as HUDCO? No, say architects Revathi and Vasanth Kamath, who have been developing technology using unstabilised mud blocks and adobe. "Large agencies like HUDCO cannot disseminate this technology effectively. It can be done only at the human level, on a one-to-one basis," contended Revathi Kamath. Despite the large amount of funds available with HUDCO, she added, it has failed to complement effectively the country's efforts to launch a cost-effective, environmentally friendly housing programme. But Patara argues agencies interested in mud-building have neither consulted and nor worked sufficiently with HUDCO.

The vast majority of India's population cannot afford even the cheapest modern house. This fact and the lack of any major effort to develop cheaper alternatives to conventional building materials, has resulted in middle-class families staying mostly in low-cost housing schemes.

Among the limited solutions to the housing problem, the use of mud is perhaps the most practical, as this technology is acceptable in rural India and mud is easily available. Some schemes have been undertaken to take this technology to the people. Patara said at least two district rural development agencies in Bihar have adopted mud technology to build houses under the Indira Awaas Yojana (IAY). Unfortunately, programmes like the IAY have not been able to provide an adequate blueprint for use in other parts of the country. The housing units under IAY were constructed by contractors and labourers, without the involvement of the people who were to stay in them and did not reflect their traditional social order.

According to Revathi Kamath, if a technology is to work, the people must be involved in it. "People should be involved in building at least the walls of their houses with their own hands, using traditional mud technology," she said. Women, she added, have traditionally been both the builders and designers of mud houses and it is essential to recognise this.

B S Bhooshan of the Institute of Development Studies in Mysore agreed with her and said, "Housing programmes should be non-paternalistic in nature. It should promote self-help."

Formal schools of architecture have not evinced any serious interest in mud technology. HUDCO's Suresh recounted his colleagues in engineering and architecture hadn't studied mud architecture nor was the subject included in the curriculum of training schools, though it is a fact that only a miniscule number of Third World residents will be able to afford conventional housing.

If the government is serious about providing housing for all, then it has to adopt mud technology. Just as energy planners are looking at simpler techniques and at traditional and renewable energy sources, so also must housing planners consider new building materials and techniques, especially those involving traditional materials such as mud.

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