House that nature built: From collecting rainwater to recycling used water

Harnessing natural light, wind and raindrops to make houses. This was the concept Abijith Priyam focussed on for his debut venture of building eco-friendly houses. His company, buildAhome.com, creates sustainable houses from naturally available resources. 

An engineer by profession, Priyam, along with his team of 50 people, takes into account simple concepts of everyday science to construct eco-friendly houses that can leave you impressed. The venture was started in 2016 and so far it has built 45 houses across the country.

The team recently worked on a house in Mangalore that is fittingly named “urvi”, which means earth. It focuses on the principles of sustainable architecture and leaving minimal carbon impact on the environment. This seemingly simple idea, however, was hard to implement in a city like Mangalore where there are two seasons of extreme weather – hot summers and incessant rains. “We wanted to build a home that did not need any additional cooling. That is, it will cool on its own and not with the help of air-conditioning,” says Priyam.

The company designed the concept of the house keeping the city's weather as the central theme. Hot summers meant long sunny days and so solar panels were installed on the roof that generate the entire electricity requirement for the house — from lighting bulbs to heating water. “We gave used solar roof tiles as well that not only generate heat, but act as a substitute for Mangalore tile. The PV (photo voltaic) panels too are used as a material for roofs,” he adds.

The second defining feature of this house is the way it uses water. Most of the requirement is met by rainwater. A borewell is provided only as a backup for the dry months.The house has an underground tank, with a capacity of over 50,000 litres, and recharge pits to tap rain water to replenish the ground water. The water used for everyday chores is also reused. “The house recycles and reuses its water through what is called a grey water filtration technique. In this, the water from the sinks, the kitchens and the showers get recycled, and is used for flushing and landscaping purposes,” says Priyam. 

The recycling is done using an oil and grease trap, a rain water filter and a water filter with chambers that purifies the water. The house also has a natural cooling system. Cool air comes from two water bodies within the vicinity and the draft enters the house via a 12-feet jaail wall and roof ventilators that have been incorporated in the design.

The eco-friendly concepts extends to every aspect of the house. The exterior of the house is made of clay products and locally-sourced materials. Although concrete is used in the core structure, the amount is half of the requirement of conventional houses. “We have used earthern pots and filler slabs for the concrete structure. This helps in cooling as well as reduces the use of cement and steel,” says Priyam.

The flooring of the house, on the other hand,  is made of athamagudi tiles that are handmade and thus more eco-friendly because factory-made tiles emit a large amount of greenhouse gas. For the stairs, the pond and master bedroom, hardwood flooring is used. The chipped off and leftover tiles from inside flooring and granite are used in the terrace. The terrace has a high-performing thermally-insulated and water-proof membrane that is protected by these broken tiles which prevent the roof from heating at all.

The wooden doors and windows are reclaimed from demolished homes. No new tree was cut for the doors or windows of the home. The glass window panes allows light to enter the house but not heat. The two skylights of the home too have the same high-performing glass and the false ceiling in the living room is made from locally available bamboo. The house has an abundance of greenery inside as well as outside. Instead of a brick compound, the house is fenced by plants. There are plenty of plants inside too. Besides keeping the air fresh, these plants have properties that repel mosquitoes and reptiles away.

The company is now working on a project in Bengaluru and Mysuru each. "More and more people now are willing to go for an eco-friendly house," says Priyam. The only reason people do not want a green house, he says, is lack of awareness and misconceptions about costs. “This entire Mangalore house, including the fittings, cost Rs 57 lakh. So, it is not that building a green house will cost you more. The difference is only in the products that go into building the house, and how you procure them,” says Priyam.