The A to Z of green buildings

Green buildings not only ensure the quality of life of those in the building is better but also increase their productivity and reduce the chances of injuries. [iStockphoto]

As the world this year marks the 30th anniversary of the adoption of the United Nations Framework Convention on Climate Change (UNFCCC) culminating with the 27th Conference of Parties (COP27) caucus in Egypt, green(ing of) buildings will be one of the key topics explored.

Concerted efforts to make lives more comfortable with solutions around architectural designs and engineering of buildings have, in the recent past, seen an increase in the number of green buildings around the world.

But what are green buildings?

Green buildings are constructions that preserve the environment by reducing the wastage of resources and cutting down on emissions of greenhouse gases.

The United States (US) Environmental Protection Agency (EPA) describes green building as the practice of creating structures and using processes that are environmentally responsible and resource-efficient throughout a building's life cycle from siting to design, construction, operation, maintenance, renovation and deconstruction.

"This practice expands and complements the classical building design concerns of economy, utility, durability, and comfort. Green building is also known as a sustainable or high-performance building," EPA says.

What is a green building expected to achieve?

Companies are coming in strongly to not only enable green buildings but to themselves take part in building environmentally friendly houses with an aim to reduce carbon footprint.

Architecture 2030, which aims "to rapidly transform the built environment from the major contributor of greenhouse gas emissions to a central solution to the climate crisis", writes that the built environment generates nearly 50 per cent of annual global carbon dioxide emissions.

"Of those total emissions, building operations are responsible for 27 per cent annually, while building materials and construction (typically referred to as embodied carbon) are responsible for an additional 20 per cent annually," it says. World Green Building Council says green buildings "can not only reduce or eliminate negative impacts on the environment, by using less water, energy or natural resources, but they can - in many cases - have a positive impact on the environment (at the building or city scales) by generating their own energy or increasing biodiversity".

Is Kenya making any efforts towards greening?

Yes. In 2013, Laikipia's UasoNyiro Primary School was named one of the two greenest schools on the planet by the US Green Building Council. The school was lionised for taking advantage of the little rainfall available in the semi-arid region and collecting its own water.

"The school collects about 350,000 litres a year, using a big storage tank underneath a central courtyard. Water falls off its roofs (about 6,500 square feet in all) into the yard, where it goes through a clay-based filtration system," Fast Company wrote then.

Many other local buildings such as the Learning Resource Centre, Catholic University of Eastern Africa, United Nations Environment Programme (UNEP) Building, Nairobi, and Strathmore Business School, which has in the past been awarded the Best Green Building Development in Africa by the African Real Estate and Housing Finance (AREHF) Academy Awards, have featured in prominent lists.

The I&M headquarters on 1 Park Avenue, Nairobi has lately joined this impressive list. Located in First Parklands, it is a Grade A category building and has a large installation of the Building Integrated Photovoltaics skylight using amorphous silicon technology.

Most of the functions on the building are solar-powered. It also has a glass roof which allows natural illumination to enter the building.

"The glass also filters out up to 99 per cent of harmful ultraviolet light, 95 per cent of infrared radiation, insulating the building both thermally and acoustically and thus minimising the energy demand of the property while increasing its value," the bank says.

The building uses the solar photovoltaic panel system which produces more energy than the building requires, with the surplus energy traded. The potential electricity generated per year will be 111,359 KwH and hence a potential save of 74,611 kg of carbon dioxide emissions and 145 Barrels of oils annually, I&M says.

The building recycles all waste generated therein, "saving the environmental impact of 61,749km by an average car with fuel consumption of eight litres per 100km, equivalent to 123.5 trips from Nairobi to Mombasa," I&M says.

Between January 2021 - June 2021, 70 per cent of waste was recycled, a saving of 19,050 kgs of Green House Gases (GHG) emissions. Between July 2021 to April 2022, 71.9 per cent of waste was recycled. This translates to a saving of 21,550kg of GHG emissions.

What are the key advantages of greening buildings?

Improved indoor environment: Superior air quality, lighting, thermal conditions and ergonomics have a positive rejuvenating impact on people working inside an enclosed space.

Green buildings not only ensure the quality of life of those in the building is better but also increase their productivity and reduce the chances of injuries.

Green buildings promote the existence of natural ecosystems as well, with some of them promoting natural greenery. [iStockphoto]

With a superior interior, the resale value of a building is consistently and constantly high.

Saving Water: In many green buildings, wastewater from the building can be recycled or reused.

This reduces the wastage of water. In some of them, rainwater is collected and all of it is used inside the building after it has undergone purification. Some of the ways through which to ensure nominal and efficient use of the water available include greywater recycling, pressure reduction, cooling towers (to save on energy) and low-flow plumbing fixtures, which save on water.

Saving energy: Greening of buildings is mainly done to save on energy or to make them reliant on clean sources such as solar energy. Some buildings purely depend on sunlight to light their interiors, cutting down the cost of electricity and powering their needs using easily available, affordable solar.

Green buildings are also made to create a conducive and soundless environment to increase the well-being of those working inside the building. "Green buildings are designed to provide optimum sound presence, which includes proper sound insulation and acoustics.

They are made to fit and amplify the natural sounds and cut out the cacophony of irritating noise," writes Eartheclipse, a site that runs campaigns on climate change. People inside a green building have a heightened awareness and concentration and are likely to perform better.

Conserving the environment: Green buildings also preserve the environment as they are meant to.

They promote the existence of natural ecosystems as well, with some of them promoting natural greenery.

Cost-effectiveness. By efficiently using resources and thus cutting down on the usage of power and water, green buildings are cost-saving for investors and users. A reduction in operational and maintenance costs would mean that landlords can collect more taxes for their buildings.

What are the disadvantages of green buildings?

Initially, it is expensive to build. Apart from the high investment in terms of initial capital, it takes a longer time to complete such buildings. Selecting materials for use is also a daunting task. Often, it is not easy to control the air temperature in green buildings. Lack of expertise when repairing, and maintaining, such buildings are also an industry challenge.