SATURDAY, NOVEMBER 27, 2004 12:00:00
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 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.
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.
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.
2005 Times Internet Limited. All rights reserved