It was a cold February evening in a village in Punjab, and the housewarming party of a palatial house had just got over. The architect who had built the mansion, that had a huge atrium that formed the sitting room, wanted a tour of the big house across the road. The neighbours warmly welcomed them into their house. Hardly had they stepped in, when the visiting lady remarked, “Now, this is housewarming. It is so warm in here.” The architect asked, “How is it so warm? Do you have central warming?” The owner's answer—no.
Built to be sustainable and energy efficient, the house faced the winter sun, with windows letting in sunshine and warming up the place, and hollow blocks keeping it insulated. It not only cut electricity bills, but also hedged the family against the erratic power supply. The proud owner of the house explained that there was no high atrium because hot air rises up, and in winter, the room below could be robbed of warmth. They did, however, have a skylight, he said, pointing to a medium-sized one about eight feet atop the staircase. An outsized skylight could add to the scorching heat during summer, and in winter the direction of sunlight would have changed! Lights needed to be switched on only when it was dark outside. With all this in mind, sustainable houses could easily be facing a different direction from other houses on the road.
Said green architect Sumedha, “Energy efficient and sustainable houses have to be designed keeping in mind the location and weather conditions.” And, of course, there is the savings factor—sustainable houses come with features that are designed to save money as well as the environment. They can look very artistic, too.
As water shortage shows up in different parts of the country, there is a growing consciousness among people in big cities and the countryside on recycling used water. Magsaysay award winner Rajendra Singh, India's 'Rainman', says water should be recycled and reused many times before it is allowed to go into the sewage system. Rainwater harvesting is a well-known way of conserving water, but dependent heavily on the rainfall in the area where a house is. The Anangpur Building Centre (ABC), on the outskirts of Delhi, advocates harvesting all non-pathogenic used water—water that flows out of the kitchen taps, washroom taps and showers—through perforated underground pipes, so that it recharges the ground. The water from the flush tank alone is allowed to go into the sewage. A post on social media recently showed how the Japanese reuse water—the wash basin is atop the flush cistern. And, at one conference where a smaller cistern was being designed, a citizen came up with the idea of leaving a couple of sealed, filled PET (polyethylene terephthalate) bottles in the cistern—which would reduce the water that is flushed out. “We have a water problem, so I have done just that,” said Madhu Gupta, a homemaker in east Delhi. The water in the overhead tank of her house lasts longer than that of her neighbours, she said.
One big element that goes into the making of a sustainable house is the choice of material used—they are largely local to save on transport costs. And, many committed to sustainability are even exploring the idea of filling PET bottles with soil and gravel, and using them in place of bricks. “These would be very much like mud-reinforced blocks,” said mason Vinod Kumar of ABC. He has recycled old bricks, used broken tiles to make a mosaic floor for a client, and used old rustic styles of casting a roof without reinforced cement. He said that the traditional styles in different parts of the country are naturally sustainable and in sync with the local weather.
Beyond construction, landscaping, particularly the choice and location of plants and trees, also plays an important role. It is common to see house owners choose deciduous trees in north India—they give shade during summer and let in sunshine when the leaves fall in winter. Taking it one notch further, house owners and landscapers are choosing plants that keep away mosquitoes and purify the air around. At a design institute's annual function a few years ago, creepers had been used very effectively to do what fairy lights would do, by adding just one low watt bulb for light.
The use of solar energy to heat water and electrify parts of or the entire house is the next level of sustainability, calling for additional investment.