Earth Architecture is here to stay

The world is quietly screaming sustainability to survive longer. For some countries, sensitivity to the environment is the new norm. For others, adopting sustainable method towards building and construction is a slow but fruitful realisation. Auroville Earth Institute in Puducherry is quietly shaping a new Earth revolution. Team Urban Vaastu finds out…


AT a time when the world is slowly waking up to the disastrous effects of indiscriminate urbanisation and unplanned concretisation, the Auroville Earth Institute is trying to make a difference by re-introducing elements from Mother Earth that are sustainable and sensitive to the environment.
As per historical records, it was in the 20th century that we really let go of our medieval roots and our deeper connection with our Earth to make ‘modern, fashionable’ buildings and infrastructure that spoilt and abused the environment. Even today, every single continent, and nearly every country, possesses a rich heritage of earthen buildings – from the roof of the world in Tibet, or the Andes Mountains in Peru, to the Niles shore in Egypt or the fertile valleys of China, many are the examples of earth as a building material. With the world’s awareness for sustainable development growing for the past few decades thanks to the ill-effects of greenhouse gases and the depletion of the ozone, sustainable building is slowly becoming a norm and more and more architects and developers are veering towards earthern architecture and construction, which benefits now from scientific researches.

One such example is the Auroville Earth Institute in Auroville (AVEI), Puducherry, in Tamil Nadu that was set up by HUDCO, the Government of India in 1989 to research, develop, promote and transfer earth-based, sustainable building technologies. The Institute’s core objective is to teach budding architects and builders the importance of linking ancestral and vernacular traditions of raw earth construction with the modern technologies of stabilised earth. This technical education is then imparted through training courses, seminars, workshops, books and manuals and, research based documents. Today, such trainings on sustainable development in buildings is imparted through services and consultancy within and outside India.
For Satprem Maini, a French architect, rediscovering ‘earth architecture’ is the process of understanding and re-using techniques that were used by our ancestors in the making of dwellings and homes. Living in Auroville since 1989, Satprem is the director of AEI. “Across the world, there are numerous examples of earth construction. And there is a remarkable balance and harmony of these buildings with the landscape and the surrounding environment,” says Satprem.

Satprem specialises in the use of raw earth as a building material and especially compressed stabilised earth blocks (CSEB). He has also specialised in the construction of arches, vaults and domes built with earth, disaster resistance with CSEB and earthen heritage conservation. The CSEB, designed by Satprem, are made by mixing earth with sand and stabilised with 5 per cent cement. This mix is then compressed in a manual press. The blocks are energy effective as the process does not require burning. It is also cost effective since a plain block is 23.6 per cent cheaper than regular bricks. But the concept is yet to gain prominence in India. “In India, the main challenge is to change the mindset of people and make them to understand and accept the concept of Earth Architecture. People think that this type of architecture may not be long-lasting. But that is not true,” he says. The Auroville Earth Institute’s core mission is to demonstrate that earth, as a building material, can be used to create modern, progressive, eco-friendly and safe habitats. Sunayana Basu, an architect from Kolkata who has trained at the Institute adds, “One of the reasons I took up a course at Auroville Earth was because they teach and practice


sustainable resource management for both human and natural resources. Interestingly, they help teach the use of our most basic natural ingredient – raw earth using cost effective technologies, affordable to all. This empowers people to build their own dwellings using natural techniques which is good for the environment around them as well.” Raw earth for building has been used worldwide for millennia but during the 20th century most of the skills of earth builders were lost and building with earth became marginal. Through the endeavour of the Auroville Earth Institute, Auroville is today reviving these traditional skills and demonstrating that earth is a noble building material which can be used for manifesting modern, harmonious and progressive architecture for the third millennium. Today Sunayana teaches and imparts these natural techniques to her juniors as well in her projects in the red earth rich region of West Bengal. She also works very closely with villagers to help them use these technique to build low cost houses without any impact to the environment.
The technologies taught at the Auroville Earth Institute include Compressed Stabilised Earth Blocks (CSEB) walls, Hollow Interlocking (HI CSEB) walls for disaster resistance, CSEB arches, vaults and domes, Stabilised Rammed Earth Foundations (SREF), Stabilised Rammed Earth Walls (SREW), Earth composite technologies for columns and beams, Stabilised earth waterproofing, plasters and mortars, etc. The most promoted AVEI technology today is Compressed Stabilised Earth Blocks. CSEB is a modern, cement or lime stabilised advance upon traditional building methods, which was developed in the 1950’s for structural, load-bearing strength and resilience against climate. CSEB may be compressed either with a manual or a hydraulic press and stabilised with as little as 5 per cent

cement to produce structural masonry units with greater strength and longevity than the average country fired brick. AVEI has designed a whole range of machinery for producing CSEB, including manual and hydraulic presses.
From the early days of Auroville, in the 1970’s, different experiments have been made with earth building, with mixed results. Those of us who have visited Auroville and marvelled at the free spaces there can now realise that what they saw was built from the earth they walked on. The creation of the Auroville Earth Institute in 1989, the construction of the Visitors’ Centre from 1989 to 1992 and the development of Vikas Community from 1992 to 1998, started a new era in earthen architecture in Auroville. Built of compressed stabilised earth blocks, it demonstrated the potential of stabilised earth as a quality building material. Today, Auroville can show a wide variety of earthen projects: public buildings, schools, apartments and individual houses.

Earth Based Technologies
Most of the technologies developed are mastered and the present research is focussed on alternative stabilizers to cement and alternative waterproofing with stabilized earth, composed of soil, sand, cement, lime, alum and tannin.
The following technologies have been mastered and are disseminated since years:
Stabilised rammed earth foundations with 5 % cement
– Stabilised rammed earth walls with 5 % cement, rammed manually
– Composite plinth – step plinth with CSEB, plinth beam with reinforced concrete cast in U shaped CSEB
– Composite columns – Round hollow CSEB with reinforced cement concrete
– Composite beams and lintels – U shaped CSEB with reinforced cement concrete

- Wide variety of compressed stabilised earth blocks (17 moulds are presently available for producing about 75 different types of blocks)
– Various vaults with compressed stabilised earth blocks
– Stabilized earth mortars and plasters

The following technologies are still under research and they will be disseminated only once mastered:
– Composite blocks (earth, fibres and stabilizer)
– Alternative stabilizers to cement (“homeopathic” milk of lime and alum)
– Alternative water proofing with stabilized earth (soil, sand, cement, lime, alum and tannin from the juice of a seed)

Since 1996, the Auroville Earth Institute, which is now representative for Asia of the UNESCO Chair “Earthen Architecture”, has been developing an earthquake-resistant technology with hollow, interlocking CSEBs. This technology was used extensively in Gujarat after the 2001 earthquake and received approval from the Gujarat and Tamil Nadu state governments as well as the Iranian government.
The Auroville Earth Institute is currently planning a major initiative for the extension of its educational programs and facilities. The new facilities are now being designed to meet the increasing demand for education in earth technologies, and to make a greater impact on affordable, sustainable, climate resilient housing in India and globally. AVEI will introduce 1-year diploma programs for post-graduate students of architecture and engineering, masonry technicians, and vocational masonry craftsmen.
Through the endeavour of the Auroville Earth Institute, Auroville is today reviving these traditional skills and demonstrating that earth is a noble building material which can be used for manifesting modern, harmonious and progressive architecture for the third millennium.