Also known as eco-friendly construction, green building entails the creation of structures that have low environmental impact throughout their life cycle: from design, construction, operation, maintenance, renovation and demolition stages.
It is important to note that green buiding techniques differ from region to region, but the general areas of action include structural design, energy efficiency, materials efficiency, water efficiency, operations and maintenance optimization and waste and toxic reduction.
The objective of ecological construction is to reduce the negative effects buildings have on the environment, including emitting carbon dioxide and other toxic gases, depleting earth’s resources through irresponsible harvesting of materials and global warming.
Environmentally friendly construction calls for the following (among other) interventions:
1.) Orientation: Long facades of a building should face south or north where solar radiation is less.
2.) Sun-Shading: Fins, balconies as well as deep recesses should be used to control the amount of sunlight entering a building.
3.) Construction materials: The wall of a building should be thick to absorb heat and conduct it slowly, thus preventing overheating on the inside of the building. The exteriors should be light coloured to reflect solar radiation hence reducing heat absorption.
4.) Natural lighting: Full-height windows should be used to ensure natural light reaches every space. As a rule a window on a 3m high wall will cast light up to 6m into the building. This means a building should have facing windows at 12m spans.
5.) Natural ventilation: This is achieved through the use of permanent ventilation louvres. In addition to that, thermal chimneys fitted with cowls assist in expelling hot air at the top.
Notable green buildings in Kenya include the Coca Cola’s new headquarters in Upper Hill, Standard Chartered’s new building in Westlands, English Point Marina (valued at Sh4 billion) in Mombasa and Medina Palms in Watamu.
The English Point Marina – targeting high end tourists – plans to install technologies that will reduce energy consumption by 15 to 20 per cent in each apartment, while recycling of used water for re-use in toilets is expected to reduce the need for fresh water by up to 60 per cent.
The proposed KCB Plaza in Upper Hill is among the latest building to be constructed using green construction materials and techniques.