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Harnessing traditional architecture and modern science

Sustainable habitats can make not only ecological but also commercial sense. The Energy Research Institute (TERI) in India has built a RETREAT – a residential training facility for executives – designed to be self-sufficient and independent of any external power supply. The energy-efficient building employs an array of techniques – a ‘combination of modern science and traditional knowledge’– to achieve not only considerable savings in energy consumption but also to reduce its ‘ecological footprint’.

The complex has harnessed both traditional and modern means of tapping renewable sources of energy to offer modern amenities such as lighting, air conditioning, cooking, laundry, and so on at substantially reduced costs. The complex saves 40%-50% of energy costs over conventionally designed buildings at an additional investment of about 25%.

Twenty-four solar water-heating panels provide up to 2000 litres of hot (65 °C) water every day. Energy is captured by rooftop solar photovoltaic panels to charge a battery bank, which is the main source of power at night. Firewood and waste biomass fuel a 50-kilowatt gasifier, which is the source of power for the building during the day. The gasifier runs a generator which has cut diesel requirements by 70%.

A network of underground air tunnels circulates cool subterranean air throughout the residential block to ensure that the temperature in the complex remains more or less even all year round. Effective insulation and shade trees also contribute.

Specially designed skylights provide daylighting to the complex; this combined with energy-efficient lights and a sophisticated system of monitoring and controlling the consumption of electricity illuminate the complex.

Finally, waste water produced at the complex is recycled by a bed of reed plants that clarifies 5000 litres of waste water every day; the recycled water is used for irrigation.