Build for comfort

BY LYDIA LIMBE

One of the advantages of living in a tropical country like Kenya is that the weather is mostly warm all year round. However, some parts of the country experience extreme hot weather, and if this is not put into consideration when one is building their own home, they may end up being uncomfortable in their own space.

The sun is the biggest source of natural lighting. While building your home in a hot area, structure it such that it allows light to come in, but keeps out the heat. “The most important element is to align the orientation of the building with the direction of the rising and setting of the sun. The sun rises in the East and sets in the West, and once you have determined this, you design your house such that the big windows face North and South,” says Joe Mugo, an architect based in Mombasa.

The hot areas in Kenya are the Coast, North Eastern,  Nyanza and parts of Eastern and Rift Valley. The most common method used to cool houses built in such areas is the cross-ventilation. “Cross-ventilation is the placement of windows in the opposite direction, so that when wind comes in through one, it directly goes out through the other, allowing for full circulation of air,” says Fredrick Muchiri, an interior designer.

Another alternative is to use sun shading, most of which are made of aluminum. The shiny finish of the aluminum reflects back some of the sun’s rays, reducing significantly the amount of heat coming into the house.

Architect Mugo explains that though it is not often put into consideration, the distance from the floor to the ceiling when building a house in a hot area, should be slightly higher than the standard height, with ventilation at the top.

“The standard height of the ceiling from the floor is 2.5 metres. But for this type of house, it should measure at least 2.8 metres from the floor. This is because hot air rises, and to enhance airflow, it needs to be allowed to leave the room as cool air comes in. That is why there is ventilation at the top,” adds Mugo.

Use of colours

Does painting the exterior of the house white help in reducing the heat in the house? “Not necessarily. How cool a house is depends on the structural placements that were considered during the planning stage,” Mugo points out.

On the other hand, the choice of colours used in the interior of the house will either give the cooling effect desired, or contribute to the feeling of being hot.

“Cool colours give the psychological feeling that the house is cool. Therefore, one can choose to paint their house with a combination they like,” says Muchiri.

You may have taken shelter from the scorching sun or from the rain, right under a window but outside a building. This is a roof over-hung, which architects use to reduce the amount of heat coming into the house without keeping out the light. The further away it is from the roof, the cooler the house becomes.

Finishing choices

Muchiri says there are some home finishing and furnishing one can use that will complement the efforts laid down by the architect. “You can use tiles, as they are known to be cold. Weather strips at the bottom of the door are equally important to stop the entry of hot air from the space at the bottom,” adds Muchiri.

He notes that heavy drapes can be used to cool the house. But in doing so, he warns, be sure to have big windows that can still let in light. Fredrick also says that not only does planting trees and flowers add aesthetic value to the overall look of the home, but it also acts as a shield from direct rays of the sun.

“You will find that the room whose side of the wall is close to the trees is cooler than the rest of the house. Therefore, it is advisable to plant trees all round the house, wherever possible,” Muchiri points out.

Technology has also brought new ways of keeping the heat out of buildings — both residential and commercial. Currently, there is low emissivity glass that allows light to come in but keeps the heat out. They have reflectors, and are usually coloured blue or green (like the I&M Bank building in Nairobi) with anti-glare mechanism. One can also do double-glazing or triple glazing of the windows.

“This means that while installing windows, you put space in between them to act as insulators. You can put two air spaces or one,” says Mugo.

Furnishing

He further points out that the type of furniture used also matters. “For instance, people like furnishing their houses with leather seats, but this can be uncomfortable to sit on especially when you are in a hot area. Instead, choose seats draped in soft fabrics, or furniture that is organic like bamboo, or hardwood made with perforations. This will be more comfortable, and will allow for free flow of air compared to the leather seats,” Muchiri points out.

He further advises homeowners in such regions to use low heat emitting sources, being careful not to use that which attracts insects at the same time.

Mugo warns that although it is common practice on the coastal province to use coral stones to build houses, they are not necessarily the best material as far as heat regulation is concerned.

“The nature of the coral stones is such that during the day, they absorb heat slowly, therefore, the house is cool at that time. But at night, they start emitting the heat they absorbed, making the house uncomfortable,” says Mugo.

He further notes that even though it is advisable to have large windows, it is also important to have a wind controlling mechanism, to allow the occupants control the amount the of wind that comes into the house, especially when there are strong winds.