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CLIMATE & ARCHITECTURE
SATURDAY, NOVEMBER 27, 2004 12:00:00 AM
Charles Correa

Charles Correa, a well-known architect once said, "form follows climate". This thought essentially suggests that a built environment can respond to climate or use it as an advantage. Traditionally, most buildings fundamentally responded to climate. For instance, if you look at the indigenous development in coastal Karnataka, most of the structures have sloping roofs in response to the heavy rains. But with globalisation, we seem to be losing out on many of these useful indigenous design solutions.

These renewable energy practices result in more attractive living spaces with open, naturally-lit spaces and fresh air movement. Solar passive or climatic design creates a comfortable setting and can also have an enormous impact on reducing operating costs of a building. By logically applying design principles that capture natural breezes and the sun's energy, electricity used in buildings can be reduced considerably. "A building that responds to climates essentially harvests light, air and water by using various design techniques," says architect Sanjay Mohe. These practices can also improve the environment and strengthen the economy by cutting down the need for fossil fuels and nuclear energy.

Day lighting

Day lighting or the use of natural light in a building is one of the fundamental elements of a climatic design. It reduces the need for electric lights and improves the visual qualities of a space. The most common ways to get daylight into a building is to increase the number and size of glazed areas in a building. There are various architectural designs or techniques that accomplish this, including conventional windows, atriums and skylights. Windows are the most common means of day lighting. An atrium is an interior courtyard and could be covered with glazing or a transparent skylight, to allow direct and diffused sunlight into the building. Rooms adjoining the atrium benefit from daylight entering through the glazed roof. A skylight is a transparent panel set into a roof that allows direct and diffused sunlight into the building.

Building orientation is an important parameter for a climate-responsive building. The amount of daylight received by a building is determined by its orientation. And the north is considered ideal as it receives uniform uninterrupted light through the day, so most of the living spaces can be positioned accordingly. Design approaches can also shut out excess heat from entering the living spaces. With innovative orientation you can stop the harsh south-west radiation from coming into the building. Further, using solar shade screens, roof overhangs, awnings, trees and other landscaping can also shade the indoors.

Wind

The use of natural winds to enhance the living environment is another solution offered by climatic design. "Air movement is essentially a design issue. One of the easiest things to do is close the building and air-condition it. A place like Bangalore does not need air conditioning for most part of the year. So using air movement and ventilation effectively can cut down energy needs," says Mohe. To improve cooling, a building's windows should be placed and designed to capture prevailing winds. And Mohe also suggests the use of 'venturi effect'. It is essentially about looking at design in volumes i.e. when you force a wind to move into a narrow opening and expand into a larger volume, the effect can be quite incredible. This design strategy creates what is referred to as wind tunnels and keeps the living spaces cool and airy." In fact this idea always works irrespective of the predominant wind direction", adds Mohe.

Cross ventilation is yet another idea. It involves a window that opens to the wind allowing breezes into the building and another window on the opposite side that lets stagnant air to be flushed out. This strategy creates continuous air movement in a space.

Landscape

Landscaping is another design tool. For example, extensive use of trees minimises heat build-up around buildings. Placing trees along the southern face of a building will provide shade and heat reduction in the summer. In addition, fairly dense planting around houses can direct breezes for natural cooling. Another innovative idea would be to have a water body about the prevailing wind direction. And when the wind moves over the water body onto the living spaces, it can bring in gushes of cool breeze.

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