Turning over a new leaf

Heritage buildings used only 5 per cent energy from the environment, Gurgaon’s glass boxes use over 40 per cent. Learning from the past, India is trashing unsustainable glassy designs to earn brownie points, writes Chetan Chauhan.

Hawa Mahal in Jaipur and the bungalows in New Delhi’s Lutyens’ are architectural inspirations for smart designs that conserve precious energy. Using designs and materials that regulate natural air circulation within the building, making maximum use of sunlight and installing water-harvesting and conservation options are key elements that have been borrowed from heritage properties to make ecologically-sound buildings.

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“Although the ancient concepts have been altered to suit modern technologies, we are rediscovering the traditional Indian ethos of construction. Earth, water, fire, air and sky are the five key elements for a green building, which we have re-adapted to suit modern needs,” said S Srinivas, senior counsellor with CII-Green Building Council of India.

An air circulation system borrowed from Hawa Mahal keeps the corridors of The Energy and Resource Institute (TERI) building in Gurgaon and Centre for Environment Science and Engineering (CESE) building at IIT Kanpur cool round-the-clock. “Small windows and stone latticework are used to filter sunlight and allow cool air to pass through,” explained Gaurav Shorey, area convener for Green Rating for Integrated Habitat Assessment (GRIHA), the government’s green building rating approval system.

Lutyens’ concept of insulation, using thick walls, has now been replaced with insertion of insulation sheets and building air cavities within the walls to reduce the heat ingress. “It can reduce the energy load by 5 to 10 per cent,” said Srinivas.

Using such technologies has helped the CESE building at IIT Kanpur consume 60 per cent less water and energy as compared to a conventional building its size. For this, it was recently awarded a five-star GRIHA rating — that evaluates the environmental performance of a building over its entire life cycle — and became the first government building to earn a green label. The CESE building scored 93 points on the 100 point table.

The building, which was initially projected to use 240 units of electricity per square metre every year, utilises only 100 units through the use of photovoltaic panels and sunlight to light up corridors. Similarly, water efficient systems have cut down per capita water consumption from 45 litres to 18 litres per day.

The ITC Green Centre in Gurgaon, which got a platinum LEED (Leadership in Energy and Environment) rating under the CII-Green Building Council, has been built to utilise daylight optimally. This saves 45 per cent of its energy requirement. The Wipro Technologies office in Gurgaon, also a platinum-rated building, saves 40 per cent of its energy needs by using wall conduction, glazing conduction, roof conduction and wall insulators, which lowers the energy load on air-conditioning. “Wipro Technologies saves Rs 1.02 lakh on its electricity bill every year,” said Srinivas.

Despite pushing up construction costs initially, energy-saving technologies work over time. “Under GRIHA, the cost may go up by 5-10 per cent but the payback time is not more than five years. After that, you save money,” said Milli Majumdar, head of environment, TERI. Even a 20 per cent increase can be recovered in seven years.

Making green buildings economically viable has helped GRIHA and LEED attract housing projects for green ratings. The Commonwealth Village on the banks of Yamuna, which would be converted into a housing complex after the Games in 2010, has applied for green rating and is looking at saving energy up to 40 per cent. The council has got 65 housing projects registered with it for green rating. “We have modified the principles for rating homes because the centralised energy-efficient systems like solar water heating systems don’t work there. But most other concepts can be applied in homes,” Shorey said.