Use weather elements to your advantage

You have just secured a bank loan to buy a piece of land to build a family home. Taking a friend with you, you drive past Athi River towards Kajiado where the many ‘Plot for Sale’ signs beckon.

You strike a good deal with the owner of one of the plots and — assuming there are no legal encumbrances — you make the required payments. Your lifelong dream of joining the homeowners list is now on course.

This procedure is followed by many Kenyans daily. But how many of us have ever given thought to the fact that how we orient the structure on the site may determine whether or not the design is sustainable?

Very few people do prior site analysis to ascertain how the area’s climate will affect day-to-day living. According to green design experts, a building’s orientation is as important as all the other design factors.

When building in the tropics, the annual movement of the sun is an important consideration. Care should be taken to minimise direct solar radiation.

“The layout should be designed to place living rooms and the kitchen in the North-South direction. Service areas such as stair cases, stores and toilets can be placed on the East-West side,” says UN-Habitat Urban Energy Unit.

In the same vein, a building should be oriented to take advantage of natural ventilation. That means you must consider wind direction when putting up your house.

In Africa, sustainable cross-ventilation requires installing low-lying wind intake openings, while placing outlet windows on the opposite side.

“Knowledge of the speed and direction of prevailing winds will facilitate natural ventilation. The main road orientation should follow the wind direction to assure natural ventilation and dust removal. A compromise should be made if the prevailing wind directions are in conflict with the sun path,” states UN-Habitat.

In addition, care should be taken when constructing in areas known for above-average rainfall, especially if the rainfall rate on the surface is in excess of what the ground can adequately absorb. Many low-lying areas in Nairobi consist of black cotton soil that drains slowly.

Interestingly, most people buy land with little consideration to the above points only to spend more money to mitigate against the elements.

Experts recommend that one should inspect the land when all these elements are at their peak so as to come up with a proper analysis that will help you make a wise decision.

As the recent floods in the country have revealed, in a fight between humans and nature, we always lose.