‘Green revolution’ in Kenya

Modern and elaborate glass structured designs borrowed from western capitals stand tall in Kenya’s skyline, yet they do not meet green architecture threshold. How green should a building be to be environmental friendly? PETER MUIRURI investigates

Kenya is slowly joining the league of countries employing green or environmentally sustainable architecture in real estate development. The move is largely informed by the dwindling natural resources such as fossil fuels and water, resources that were once thought as inexhaustible.

Musau kimeu, Environmental Design Expert

The designs are also expected to reduce global warming since current unsustainable buildings in many parts of the globe contribute to at least 50 per cent of the world’s carbon emissions.

However, the full realisation of green technology is being hampered by lack of properly trained personnel in the field.

According to Architect Musau Kimeu, a leading Environmental Design Expert, Kenya has less than 20 such architects, the highest in Africa.

“Lack of proper expertise in environmental design is largely to blame for the slow progress in green architecture. Most ‘experts’ in the field usually incorporate an element or two of green design and then label the project green resulting in misinformation to the general public,” says Kimeu.

Nairobi, he says, has few buildings that are well designed to make use of locally available materials while minimising energy consumption and maximising the use of non-toxic materials.

Experts in the field argue that Kenya had beautiful architectural designs in the 1960s and 1970s with buildings such as Parliament, the old Attorney General’s Chambers, Harambee House, the former Shell/BP House (current Office of the Prime Minister) together with a few buildings within University of Nairobi’s Main Campus falling in this category.

Foreign concept

However, the last three decades have seen a rat race as developers within our cities try to outdo each other in the erection of tall buildings that largely rely on elaborate air-conditioning system, thus contributing to carbon emissions into the atmosphere.

“Nairobi’s current skyline has greatly copied the West with a lot of emphasis on glass that makes buildings hot due to the large amount of heat that penetrates through. Such glass buildings are well suited for temperate countries in Europe and North America where heat needs to be retained. The reverse should be true in a tropical country like Kenya where heat needs to be extracted from a building,” argues Kimeu.

The question then is how ‘green’ should a structure be to meet the criteria of an environmental friendly building?

The checklist is long and detailed, a factor that may make some shy away from incorporating all the aspects in a development.

For a start, a green building should be built in a way that minimises heat gain while allowing for a natural cooling mechanism, an aspect that can be attained in a number of ways. For example, a building’s orientation should place its large, window-clad facades facing the North-South axis so that it has minimal direct solar radiation.

In the same vein, building services such as lifts, stairwells, toilets, stores and air extractor ducts should be placed on the East-West facing facades since they are not frequently utilised in the course of a working day. External finishes should be made of light coloured material to prevent heat absorption during the day.

key ingredients

The design of a green building should incorporate solid waste management, use of renewable energy, rainwater harvesting and more importantly use locally available materials.

“A number of buildings in Nairobi have recently been hyped as having attained excellent sustainable designs. However, they largely fall short of most of the parameters of green design. Their classification as such may end up lowering the requirements of green design since many developers may inadvertently use them as examples of sustainable architecture,” says Kimeu who cites the Coca Cola’s regional head office in Upper Hill, Nairobi as an example of a sustainable building.

A paper, Green Architecture: The Quest for Best practice in Nairobi, presented at the second East African Regional workshop in August 2011 at the University of Nairobi highlighted Strathmore Business School, the new Stanchart building along Waiyaki Way and the United Nation’s Office in Gigiri as examples of environmental sustainable buildings despite several environmental design inadequacies.

Few exceptions

Granted, these building have incorporated a number of green principles that stand out. For example, the UNEP building features 6,000 square meters of solar panels making it the first solar powered UN office in the world prompting the UN Secretary General Ban Ki Moon to hail the new building as “a living model of our sustainable future.”

Stanchart building on the other hand has a built-in rain harvesting system while a waterless urinal ensures that wastage of water is minimised. However, experts fault the building’s use of a hybrid ventilation system where air intake is through a mechanical system.

Strathmore Business school has been hailed for its indoor air quality system of using evaporative cooling units that use harvested rainwater. However, almost all the materials for the project were imported in contrast to one of the pillars of green design.

“There is a notion that green design could raise development costs astronomically. This is not true if the idea is incorporated in the planning phase. In any case, there will be a leverage in such costs within the first seven years after which huge savings will be accrued through lower utility costs.

A building is a long term investment and decisions made at present will have a positive impact for decades to come,” says Kimeu.

Living green

Our survey took us to the leafy suburbs of Karen where a number of developers have tried to incorporate some aspects of green design in their projects.

For example, in Sandalwood Waterfront, a conglomeration of artistically designed villas, the developer has put rainwater collected from the roofs to good use by storing it in three small lakes within the centre of the property. The water is then used to keep the grass in the expansive gardens green all year round.

Two sewer treatment plants within the property ensure that there is enough water for the gardens all year.

“Currently, we have at least 10 million litres of water that would otherwise have gone down the storm water drain. This is a concept we intend to use in our other housing projects as we try to incorporate other elements of green design,” said Sanjiv Seedhar, Sandalwood’s Managing Director.

In the same neighbourhood lies what can be termed as the real green project in the country, the Catholic University of East Africa’s Pope Paul VI Learning Resource Centre comprising of a modern conference hall, a bookshop, an extensive library and a cafeteria. Almost all the features of a green building are at work here.

The conference hall employs an intricate cooling system where air gets in through vents located at the basement level, passes over well arranged bedrock where it cools further before being released into the auditorium through another set of vents.

This is the only rock bed cooling system in Kenya.

Thermal chimneys located at various intervals of the building help expel hot air out of the building. There is no single mechanical air conditioning system in the complex.

A high roofed atrium coupled with a narrow plan allows natural lighting to filter through the building. To prevent heat build-up in glazed areas, concrete fins and aluminium louvre screens have been used.

In addition, an elaborate rainwater harvesting system and the use of oxidation ponds for the sewerage system are also in place.

It is hoped that green design will no longer be a foreign concept but a fundamental idea integrated in the basic construction plans.