Passive design and insulation can reduce a building’s energy demand and the city’s overall demand for energy, making renewables a more viable option. Increasingly, African cities have guidelines to make these shifts, but the challenge lies in making them legal requirements.
As global awareness around the impact of fossil fuels and the need for cleaner alternatives continue to grow, cities around the world are making commitments to switch to renewable energy. Yet meeting our current energy demand with renewable sources is a daunting task, especially in fast-growing African cities where energy demand and access is consistently and rapidly increasing.
Globally, buildings can account for up to 40 percent of total energy consumption and 20 percent of greenhouse gas emissions. In many African cities, residential buildings are the second largest energy consumer after transport meaning that energy efficiency in the buildings sector presents a valuable opportunity to reduce emissions. By implementing simple, affordable changes, cities are increasing efficiency, and thereby significantly reducing energy demand. Apart from lessening the city’s dependence on fossil fuels, the reduced energy demand in turn increases the viability of renewable energy systems.
Simple, affordable, building greening
Through passive design, energy efficient lighting, material adjustments and insulation, especially new buildings can greatly limit energy demand. Cities in Africa are considering green building guidelines created through the Urban-LEDS project that look not only at energy, but reducing the building’s total environmental impact. If implemented, the green building guidelines will set certain legal requirements for building efficiency.
One such city is KwaDukuza Municipality in South Africa. The green building guidelines under consideration have great potential for simple, affordable shifts that all buildings can follow. These primarily rely on passive solar design as a cost effective way to improve thermal efficiency and daylighting and decrease energy use.
Where a building has large windows, developers are required to build shading devices positioned in a way to block the summer sun, while letting in the lower-hanging winter sun. These shades will reduce the need for electric cooling in summer and heating in winter.
By building houses to face north, placing bedrooms and living areas in the north or west of the house, and service areas in south or east, both the temperature and the lighting in the building is optimized, further reducing the need to switch on electric lights. All electric lights in a building should be LEDs.
Insulating the ceilings, windows and floors provide further savings. In fact, insulating the ceiling has been shown to better manage air temperatures than heaters, fans and air-conditioning. This type of insulation, as well as insulating all exposed water pipes, is a requirement in the Green Building Guidelines of KwaDukuza.
One major shift already in place in South Africa is that at least 50 percent of a new house’s hot water has to be provided by solar heating, heat pumps, heat recovery or fuel from renewable energy (sun, wind, geothermal, biomass, etc.).
Leading the way on implementing green building guidelines
Green building guidelines can significantly reduce the energy demand in rapidly growing African cities. The challenge is to get these guidelines implemented and made a requirement for all new buildings and major building retrofits planned in the city.
A recent focus of The Building Efficiency Accelerator (BEA) is specifically on institutionalizing the Guidelines. In KwaDukuza, ICLEI Africa met with city officials to start this process. The first step was to make city leaders aware of the guidelines and to make sure that they understand them. It was also important for officials to grasp the benefits of implementing the green building principles, making them champions for the work rather than putting an onerous burden on them.
The workshop dove deep and officials co-developed ways in which to include the guidelines in application forms and processes developers and builders have to follow when building new houses.
The City’s Senior Manager of Building Control, Ms Thandeka Thwala, attended the KwaDukuza workshop and commented: “This session is the first step to realizing the municipality’s goal towards developing a green building by-law.”
A by-law would provide the push the guidelines need to become requirements and ultimately reduce the city’s energy demand as much as possible as it continues to grow.
During a separate event, the KwaDukuza Municipality joined Umhlathuze Municipality, Msunduzi Municipality, The City of Tshwane, the Kenya Green Building Society, ICLEI and the WWF to grapple with the process of developing, approving and institutionalizing green building guidelines and building codes. Bringing together the region meant that cities and municipalities could exchange knowledge and experience to collectively find ways to embed green building guidelines and green building codes in their municipalities to realize their vision to accelerate resource efficiency in buildings.
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