An agency of the Department of Transport is leading the way for government as the first parastatal in South Africa to achieve a Green Star SA rating for one of its buildings. Worldwide, buildings are responsible for a third of all carbon emissions and, given that SA has boldly committed to reducing our carbon emissions by 34% by 2020 and 42% by 2025 and that the lowest hanging fruit to reduce our emissions is through the built environment, it is especially significant that our government is demonstrating its commitment in this manner.

This step in the right direction takes the form of the new Corporate Head Office for the South African National Roads Agency SOC Ltd (SANRAL), which has been awarded a 4-Star Green Star SA - Office Design v1 rating by the Green Building Council of SA (GBCSA) - South Africa's green building authority. A 4-Star rating is defined as "Best Practice" in the rating system.

"Green Star SA rates buildings on nine categories - eight of them environmental, including Indoor Environmental Quality, Energy, Water, Materials and Emissions, and the ninth category is Innovation. The Green Star SA rating tool sets out specific targets (credits) in each environmental category, and buildings are awarded points for each credit that they comply with. The total points will determine the building's Green Star SA rating," explains Brian Wilkinson, CEO of the GBCSA.

the major focus

"Energy is a major focus, and as such, points earned in this category carry significant weight in the Green Star SA rating tool. Projects are rewarded for reducing their energy consumption. But there are a wide number of other initiatives that go into a rating." Some of those within the SANRAL building, which is situated in Pretoria, include the green roof planted with water-wise succulents, solar-generated hot water for a fresh air heating system, a facade consisting of two layers that increases natural light and views whilst decreasing heat build up. Furthermore, a specialised outer shading layer, which provides essential sun screening, has been designed.

This innovative vertical green walling system, as well as the green roof, has a substantial and significant environmental benefit by combating and reducing the Urban Heat Island Effect (UHIE). The air conditioning systems consist of two air cooled reverse cycle (heat pump) chillers with a combined capacity of approximately 75% of the peak building design cooling load. Ice is produced and stored during the "off-peak" night cycle which can supplement the cooling requirement during the day.

In the winter mode the chillers run as heat pump units to meet the heating requirements while the ice produced the previous night is melted to meet the cooling requirements. Fresh air is pre-cooled or pre-heated by recovering energy from the exhaust air by means of Heat Recovery Wheels and in winter stored solar heated hot water supplements the pre-heating of outside air by means of coils in the fresh air system.

a ground-breaking achievement

The SANRAL building scored particularly well in the Energy and Water category - significantly reducing the buildings' use of these scarce resources. "The GBCSA would like to offer our congratulations to SANRAL, the Department of Transport and the SA government for this ground-breaking achievement as the first parastatal building in SA to achieve a Green Star rating," says Wilkinson.

"Also, congratulations to the professional team involved in the development of the SANRAL building. These are Activate Architecture (Pty) Ltd; Koor Dindar Mothei Quantity Surveyors; Plantech Electrical and Mechanical Consulting Engineers; Civil Concepts (Pty) Ltd and the Project Manager and Principal Agent, Rouillard Consulting."

"Green building offers one of the simplest, most immediate and cost effective ways to reduce human generated carbon emissions - it is essentially the 'low hanging fruit' - and it is through the efforts made with buildings such as the SANRAL Corporate Head Office that South Africa will begin to move towards our commitment of reduced carbon emissions."

"The GBCSA tirelessly strives to change the way the world is built, in order to create a more sustainable future for South Africa.We are pleased and excited to have the support and buy-in from the South African government," concludes Wilkinson.

green government initiatives

Other exciting "green" government initiatives include the announcement at COP17 by the Department of Public Works that they plan to launch a National Green Building Framework that will align its green building initiatives, which will result in various national green building policies being developed to ensure that South Africa's built environment is developed in a more sustainable manner. The Construction Industry Development Board (cidb), an agency of the Department of Public works (DPW) sponsored the development of the Green Star SA - Public &Education Building Tool. In addition to this, another parastatal, Eskom, represented by its Integrated Demand Management department (IDM), has become a Platinum founding member of the GBCSA. Eskom also contributed significant sponsorship and technical input towards the development of the Energy and Water Benchmarking tool currently being developed by the GBCSA.

For more information about Green Star SA rating tools, the certification process, the Green Star SA professional accreditation and courses offered by the GBCSA, visit www.gbcsa.org.za.