Society

Homes that breathe

It’s inside the modest ‘Potter’s House’ in DakshinaChitra museum that I am introduced to the newest hot topic in architecture. ‘Sustainable living’ is a term being thrown around in top discussion platforms such as the World Economic Forum, UN Habitat, and Intergovernmental Panel on Climate Change, even forcing one of the premier institutes in India — IIT Kharagpur — to introduce a course on vaastu shastra that integrates architecture and Nature.

With cement production alone contributing to nearly 8% of CO2 emissions globally (Trends in Global CO2 emissions: 2016 Report by PBL Netherlands Environmental Assessment Agency), many heads are discussing ways to create new habitats without making Earth uninhabitable. As it turns out, the cow dung-coated mud walls and reed-thatched roof of the Potter’s House, where I stand, make for an important case study among architecture students across the world today.

The trend

Earth houses, as they are called, are making a comeback across the globe. The structures, designed to use natural light and produce natural cooling, are built with local natural resources such as bamboo, limestone, clay, cow dung, stones and straw by local artisans — reducing the carbon footprint to almost nil.

Numerous organisations — Thannal and Vasthukam in Kerala, Made in Earth in Bengaluru, Auroville Earth Institute in Auroville — and architects such as Dharamsala-based Didi Contractor, Chennai-based Benny Kuriakose, Kerala-based Eugene Pandala and Goa-based Gerard da Cunha are spearheading the movement, which was arguably kickstarted by the legendary Laurie Baker in the 1960s.

Homes that breathe

Today, Tiruvannamalai-based Thannal Hand Sculpted Homes, which has built ‘natural homes’ in Tiruvannamalai, Tumkur and Alamathi (just nine kilometres from Chennai), works with hundreds of volunteers, including senior citizens without a background in architecture and students from abroad. “A 500-square-foot home can be built in two months, if you have some friends to help you; and it costs less than a conventional home. It works out to less than ₹1,000 per square foot, depending on site, materials and labour,” says Biju Bhaskar, co-founder. This is versus the ₹1,500 to ₹2,000 per square foot for regular construction.

A step-by-step guideline for building ‘earth homes’ is available for free download on the company’s website. “The idea, besides building homes, is to create environment-conscious ambassadors. A 63-year-old teacher who volunteered with us is now building her house in Kerala.”

The method

PK Sreenivasan, founder of Kerala-based Vasthukam: The organic architects, which built the Adishakti Theatre building in Puducherry, confirms that “enquiries from youngsters have shot up over the 15 years I have been in this field.” The architect, who worked under Baker in his company Costford (Kerala), is in the pursuit of “building houses that breathe”. Smooth plastered mud walls of ochre, chrome yellow and brownish gold replace the normally-used cement, steel and bricks in all his projects. This eliminates paints that use toxic chemicals. In fact, long exposure to this can result in a central nervous system disorder called Painters’ Syndrome!

Homes that breathe

Just a three-hour drive from Chennai is Ananda Vanam in Erikarai, Thiruvannamalai — a community space run by poet Ananda Surya and his artist-wife Gayatri Gamuz — where Bhaskar, his team and a bunch of local people are building a 300-square-foot cob hut. Thannal’s website shows photos of the initial construction — people with muddy hands and clothes stand around what looks like a big ant hill. The cob — clay, sand and fibre (it can be rice straw or coconut coir) — is mixed by farm animals or using a tractor rotator and a basic foundation created. This is supported by bamboo poles and linked to form a strong monolithic structure. Waterproofing is done using a fermented mixture of kadukkai, palm jaggery and lime, explains Bhaskar from Sabarmati Ashram, from where he goes to Rajasthan to set up earth homes.

Soon after the Gujarat Earthquake of 2001, the Tsunami of 2004 and the Nepal earthquake of 2015, earth houses were constructed on a large scale with the help of local artisans (check out hunnarshala.org). Now, our traditional techniques (think mud flooring at the Padmanabhapuram Palace in Kerala or the brick walls at the Lakshmana temple, Chhattisgarh, or the houses in Dharamshala made of sun-dried earth blocks) are in the spotlight. “The old structures have stayed intact for years without damage, unlike cement (an invention just about a century old) buildings that crack in a few years, and then erode the steel within, thus collapsing the building. A good example of a resilient structure done using natural materials is Chettinad Palace, the walls of which are embellished with a plaster or vellai poochu, consisting of a lime base, ground white sea shells, egg white, etc,” adds Bhaskar. Probably, the only point where concrete wins over natural materials is the setting time, which is just 30 minutes when compared to 30 days for a mix of soil, cow dung and lime.

Homes that breathe

An ideal home should be climate relevant. “More than 90% of Baker’s buildings had sloping roofs in the 1970s and 1980s, when other architects opted for flat roofs. The overhangs of the roofs protected the walls from direct sunlight and kept the interiors cool. Buildings with flat roofs are exposed to the sun, and the walls transmit heat. Even glass roofs let in heat, and air-conditioning becomes necessary. If the electricity goes off, you will not be able to sit inside,” says Chennai-based Kuriakose, who worked under Baker, and has been involved in several restoration projects in Chapredi in Bhuj, and Tharangambadi and Chinnangudi in Tamil Nadu.

The challenge

As much as one would like to stay true to the concept of earth homes, with urbanisation, it might not be possible to build with materials available within a five-mile radius. “Cement and steel might not be avoidable. Even soil will have to be brought from outside when we think of building within the city,” says Kuriakose. The focus should be on sustainability — reduce transportation costs, recycle water and treat waste. “However, what’s scary today is that the village folk think using concrete is a reflection of status, and they have also started imitating cityfolk.”

Types of natural homes

Adobe

Soil and water are blended to the consistency of a cake mix, and cast into moulds. Once the bricks are firm, they are dried in the sun. These are then used in the buildings

Cob

Straw, soil, and, often, gravel, are mixed to form cob, which is used to form a wall of any shape

Wattle and daub

Fine sticks or reeds such as bamboo are woven and the daub or mud is applied on it to build a wall

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Printable version | Apr 15, 2021 3:23:22 PM | https://www.thehindu.com/society/the-new-age-of-earth-homes/article18246547.ece

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