Published in Mar-Apr 2022
Although designing energy-efficient buildings has been a long standing challenge in Pakistan, recent trends in construction have shown significant improvements, as architects search for solutions aimed at promoting environmentally-friendly and sustainable ways of living. Furthermore, people have become increasingly aware of the importance of adopting sustainable living options. The good news is that it has never been easier to design an energy-efficient space that reduces the carbon footprint. Here are ways to achieve this,
Orientation, Orientation, Orientation
Climate-responsive architecture can be achieved by keeping the direction of solar pathways in mind during the planning stages, which is why the orientation of a space is so important. This will determine how much sunlight the interiors receive and in turn will directly impact the temperature. Spaces should be designed keeping in mind the angles at which they will receive sunlight. Spaces built in hot climates should face the north rather than the south, as the latter’s light is intense and increases interior temperatures. In cooler climates, the location of the windows should be such that they absorb maximum sunlight.
Keeping building plans simple and allowing the maximum amount of natural wind to enter a space is another significant step to be kept in mind when designing energy-efficient spaces. In this regard, the shape and orientation of the building’s entrance plays a crucial role. Long façades should be perpendicular to the existing wind direction to allow in the most wind. In this way, the biggest natural resource is utilised to the maximum.
Although incorporating wide windows ensures proper ventilation inside the house, proper insulation is of the utmost importance in retaining heat in cool temperatures and keeping it at bay in hotter climates. If insulation is too costly, double glazing is another way to achieve the same result. Internal gardens or courtyards will allow natural light and wind to reach all spaces; they also create a natural oasis and improve the interior ventilation of the built space.
Windows and skylights affect heating and cooling costs; hence, the energy performance of the built space depends on them. The use of glass should be planned wisely with the sizes of windows and the number of panes designed with respect to optimum performance. In this regard, relatively small skylights and clerestories provide daylight in addition to the light that comes through normal windows and create a pleasant ambience. However, direct sunlight should be contained as it can cause heat and smaller apertures should be placed near ceilings to allow the heat to escape. This concept is similar to roshandaans that exist in old havelis and have been reconfigured to fit modern design philosophy.
A feature to consider are shading devices for windows and skylights. Vertical and horizontal sunshades along sun-facing aspects help reduce heat transfer. These sun breakers are known as brise soleil; they are shaded windows that keep interiors cool during the hot weather by deflecting the sun’s rays. ‘Punched out’ windows in the façade design work the same way; they use recessed glazing, providing shade from all four sides. In case construction of such shades is not possible, awnings will work. They are available in a variety of materials and sizes and can easily be replaced once they wear out. Canopies and fibreglass overhangs create similar structures for shading purposes, although awnings are the most effective alternative to permanent shades. All exterior shading requires careful orientation with respect to the sun’s trajectory. Another way to shade spaces is landscaping. Use the shade of trees and shrubs to shield buildings; they also absorb excess heat and help reduce the temperature. Using trees with canopies increases the shaded surface area. Deciduous trees work best for blocking summer heat and letting through the winter sunlight. To provide continuous shade and protection from strong winds, it is advisable to plant dense trees and shrubs. The location of the trees is very important; planting trees on the east, south and west will keep spaces cool during periods of extreme heat, trees planted on the west cast shadows that block the afternoon sun.
Modern façade design has also undergone changes and increasingly resemble perforated jalis; they keep spaces cooler and ensure privacy without the use of curtains. Cement jalis or jalis made from brick allow wind and light to enter interiors without the use of glazing and ensure that the building remains cool.
Although designing and building energy-efficient houses can be a challenge, these features, if incorporated properly, can go a long way in creating well-constructed, energy-saving spaces in the long run. They may be expensive at the start but can prove to be incredibly beneficial in the long term, saving money as well as energy in the process.
Farah Rizwan is Partner, Orphic, and lectures at The Indus Valley School of Art and Architecture.