Karachi’s sea breeze from the Arabian Sea, which cooled down the city and gave Karachiites a spring in their steps, is one of the many blessings from nature this city has received. But as the city continues to grow in size, the waterways and streams that cooled down the temperature were obstructed, tree and mangrove plantation chopped in the name of development, and hastily built coop like structures for offices and apartments have blocked the path of the sea breeze and the ventilation it offered.

“The materials used in urban areas, concrete and steel, do not have much insulation. That means that the buildings get very hot, the structures absorb heat, and buildings become like ovens unless insulated in some way,” explains architect Yasmin Lari.

“I have often suggested buildings where you may put a frame of concrete and steel, but perhaps the walls could be made out of mud bricks. Also using lots of lime and mud plaster will provide insulation for the building,” she says.

We speak to architect Yasmeen Lari about how the effects of heat can be mitigated by using smart architectural techniques

Unlike other parts of the country, where red bricks are used for construction, Karachi relies heavily on concrete, with no insulation used between bricks (since adding insulation would increase costs). Given that a large number of victims came from small homes with no proper ventilation and even tin sheet roofs, it is important that insulation is highlighted and take into account.

Lari says the first and foremost thing to do is plaster the exterior and roof with mud and lime. “A thick layer will act as a barrier. Another thing to do is to whitewash the roof (this reflects sunlight). Planting vines and trees also helps a great deal.”

For immediate relief, she says ice blocks can be placed in the room and turning on the fan will get the room to cool down a bit. At present, she says, all structures can be insulated but it will prove to be an expensive process. “Focus should be on sustainability,” she stresses.

Responding to a question on the need for green spaces, Lari said, “Any kind of vegetation is good. We should be growing vines outside homes. The problem however is the water situation in Karachi, so we need to look into plants that do not require much water but which will provide coverage to the ground. Ground coverage by foliage is very important otherwise the heat will be absorbed and transmitted to the buildings around them,” she adds.

“The more concrete and steel and industrialised materials are used, the more pollution — there is a lot more carbon emission in their production,” she says, arguing that the carbon footprint in the city needs to be reduced.

“If you look at old pre-partition buildings, they were built according to the climate of the city. The higher ceilings allowed the rooms to be cooler and helped in cross-ventilation.”

Lari says the city and most of its structures are not prepared for any disaster, be it an earthquake or a massive storm and this heatwave is clear proof of that.

“This is Karachi’s first experience with the heatwave in the present times and it has been so devastating. However, the factor of climate change cannot be overlooked. There is a dire need to focus on minimising green house gases. Global warming has changed climate patterns, the heat now is far more aggressive than before, the rains and floods more intense, the winds much stronger,” she says.

“We need to sit down and decide how to make sustainable buildings that will help us deal with climate change and avoid tragedies that happened in this heat wave.”

Published in Dawn, Sunday Magazine, July 5th, 2015

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