23 June 2014 - South Africa’s largest listed property company, Growthpoint Properties, has added another world-class building to its portfolio – 44 on Grand Central, Midrand. Engineering management and specialist technical services group, Aurecon, was commissioned to provide sustainable development guidance to the project team and to manage the achievement of a 4-Star Green Star SA – Office Design v1 rating from the Green Building Council of South Africa (GBCSA).
The elegant, high quality 7 000 m² development is located immediately opposite the Gautrain’s Midrand Station. Not unsurprisingly, Gautrain is a major tenant, having taken up 2 500 m².
Two major challenges were encountered on the project: that of a sloped site, calling for an innovative building circulation model, and the need to implement Environmentally Sustainable Design (ESD) to the highest standards, despite minimal site space.
Unique circulation model
The design of 44 on Grand Central uses a unique circulation model to accommodate a steep slope from south-east to north-west, with the south-east low point being close to Gautrain Station. Entering here at ground level, access to the rest of the building is gained via an escalator up to the main lobby which functions as an internal courtyard. This large courtyard enables daylight harvesting through central atriums at each storey.
The circulation model was thoroughly modelled using Aurecon’s energy and daylight modelling expertise, while the choice of glazing, as well as design of glare reduction features, was also optimised to ensure the maximum penetration of light as well as the comfort of building users.
The ‘green’ design of the building reflects the growing realisation that sustainable design is the means to ‘future-proof’ a building against the increasing scarcity and expense of energy and resources.
All aspects of the design were carefully scrutinised and assessed for their cost-effective contribution to the targeted Green Star rating, from structural aspects such as the use of zero carbon rated fly ash in the concrete and recyclable steel, energy efficient motors, pumps and fans, to rainwater harvesting. Finishing items such as paint and carpets were tightly specified for minimum volatile organic compounds, and a building management system was developed to reduce energy and water consumption, as well as optimise waste reuse and recycling. Air conditioning energy requirements were reduced through measures such as extensive roof insulation and zone control.
Some of the innovative aspects introduced by the mechanical engineers on the project included maximising comfort and ensuring a healthy environment for the occupants through the specification of a high fresh air ratio HVAC system, linked to fresh air fans on the roof.
The company was also appointed as landscape architects. “We addressed the problem of minimal surrounding space for landscaping and an existing unsightly walkway between the site of the building and the Gautrain Station by advising the client to turn these challenges into a positive feature for the development,” says Marni Punt, Associate – Environmentally Sustainable Design (ESD) Consultant at Aurecon. “Even though the walkway is not on the client’s property, we are busy landscaping it as a boulevard. In the process, we used the opportunity to propose a new GBCSA Green Star credit, that of ‘Transport Accessibility’, which earned the project innovation points under INN-03.”
The boulevard solution is also a way of encouraging the building’s occupants to make use of public transport as it enables more users to walk safely and comfortably form the station to their destination.
“We also earned the credit for the careful design of the external lighting,” added Karen Govender, Junior ESD Consultant at Aurecon. “By selection of appropriate fittings and specifying that the orientation of the lighting not be directed into the atmosphere, we minimised upward and horizontal lighting pollution.”
Positive tenant feedback
Completed on time and on budget after a 12-month construction schedule, 44 on Grand Central has been occupied since June 2013. The tenant feedback has been extremely positive. In addition to the high standard of operational efficiency achieved, the attention paid to external infrastructure and landscaping is expected to be catalyst for further development in Midrand’s attractive commercial node.