1. Repurpose sewage water

In 2000, Kanubhai Karkare, an officer at the education department in Amreli, designed and built his sustainable house for Rs 2.8 lakh.

Sewage water from the house is treated using two-foot-long vegetation beds with specific plants that break down complex waste elements and decompose them.

The recycled water is then used for kitchen gardening or other usages.

2. Install a hybrid solar energy system

Madhusudhan Joshi, a professor at the Goa College of Pharmacy, saw building a sustainable house as an opportunity to practice what he preached.

His sustainable house in Panaji is fully powered by solar energy but uses a unique hybrid system, where the energy is stored in a battery first and the surplus is then exported to the grid.

Joshi receives compensation from the Government based on the number of units generated.

3. IMBIBE NATURAL COOLING TECHNIQUES

In 2019, Vishwanath, a civil engineer and urban and regional planner, and Chitra, an architect, built their sustainable house at Vidyaranyapura in Bengaluru.

The two-storeyed eco-friendly house has sheets made from agricultural waste on certain parts of the roof to prevent surface heating and open arches instead of doors.

Meanwhile, the basement windows at the ground level along with the rooftop garden help in cooling the interiors of the house.

4. adopt rainwater harvesting

Rajesh and Vallari Shah moved back to India from the US in 2007, aiming to live more sustainably.

In their home, rainwater from the roof is transferred through pipes and filtered in sand beds before being stored in three underground tanks, each holding 30,000 litres.

This water is enough for nine months of the year, and they use the public water supply for the next three months.

5. find ways to generate compost

It was always a dream for Snehal Patel, a Surat-based mechanical engineer, to build a sustainable house far from the hustle-bustle of everyday life.

In his home, the blackwater from the toilets goes into settling tanks. Once the solids settle down, the water is filtered and used in the garden while the solid material is turned into compost.

6. build outlets for hot air to be released

Amrutha Kishor's bungalow with a Mangalore-tiled roof is inspired by Travancore’s traditional architecture with free-flowing spaces and grand windows.

A wind tower is constructed in the house along the staircase, using the ‘stack effect’, a physics principle that harnesses temperature variations to circulate air.

When hot air rises because of its low-pressure characteristics, the tower, which has four openings, captures this hot air and releases it outdoors.

7. choose cool building materials

Veena Lal, who runs NGO Karma Marg in Faridabad, constructed her eco-friendly home with the help of a young Mumbai-based architect named Amol Mannekar.

Her 1,800 sq ft sustainable mud house’s outer structure is built using sun-baked bricks that are plastered with mud. This provides an added layer of insulation to the house, keeping it comparatively cooler at all times.

8. construct a biodigester

Balasunda Kaushikan, a Bengaluru-based architect, built his dream home in his village in Theni, Tamil Nadu, based on the zero-waste concept.

The sustainable house was built for Rs 55 lakh and employs a biodigester tank that degrades and converts human waste into water, which is then used for gardening.

The methane gas produced in the process is used in the kitchen.