In line with the shift towards ‘green’ living, an increasing number of old South African buildings are being retrofitted to become more eco-friendly. One of the latest buildings to join the green ranks is the 5600sqm ‘Eastgate 20’ office building on the corner of Grayston Drive and Katherine Street in Sandton. Redeveloped along sustainable lines, the building was recently awarded a 4 Star Green Star SA –Office v1 Design certification by the Green Building Council of SA (GBCSA).
For buildings to be rated by the GBCSA, they need to comply with certain environmental criteria in eight environmental categories including energy, water, materials and emissions. Points are awarded in each category and these are then collated to determine the building’s Green Star rating. At present the highest achievable South African rating is a six star rating.
According to the GBCSA, Eastgate 20 is unusual in that its re-development involved the incorporation of a pre-existing car dealership, the upshot of which was that the project required far less new materials which is good news for the environment.
Briefly, the project entailed the demolition of the existing roof, the second floor and half of the first floor slab. Following the reconstruction of the first floor slab, an additional three floors were developed to accommodate the building’s contemporary office and conference facilities. The office now features four levels of office space and parking which can accommodate approximately 340 people.
Emphasis was placed on incorporating fresh air and natural light into the building’s re-development. To this end, extensive computerised daylight modelling was carried out to predict and optimise the levels of daylight achieved. The impact of glare was minimised by external louvres on the north-west façade and deep set window openings on the north-east and south-west facades. Performance glass was used on the south-east façade to control the amount of light entry and blinds were used in other select tenant areas to eliminate any remaining glare.
The GBCSA explains that Eastgate 20’s air quality was improved through the use of a mechanical ventilation system which provides 15 litres of fresh air per second per person which is a 150 percent improvement on the Green Star SA green building baseline. Low VOC paints (which use water instead of petroleum as a base), adhesives and sealants were also used inside the building, thus minimising the amount of potential chemicals that can be breathed in by occupants.
Eastgate 20 also scored well in the GBCSA’s water category thanks to the installation of water efficient fittings and meters which were installed throughout the building and on the incoming mains supply, shower supply and irrigation supply. Hot water for hand washing is provided by solar water heaters and a storm water treatment system has been installed in the exiting storm water piping.
In addition to these initiatives, Eastgate 20’s developers implemented a number of eco-friendly transport initiatives. The area in which the building scored the highest though was in the energy category. Through including efficient cooling and lighting systems, it is projected that Eastgate 20 will save approximately 40 percent of the electrical energy usage of a similar building built to the requirements of the SANS 204:2008 guide for energy efficient buildings.
Says Brian Wilkinson, CEO of GBCSA: “Buildings such as Eastgate 20 are setting the bar for the industry and prove that it is possible to reinvent our aging building stock in SA. In overseas markets such as Australia and Europe, it is becoming too risky commercially to develop buildings that are not green and we are very pleased that the South African market is rapidly following suit.”