When Grundfos, one of the world’s leading pump manufacturers and committed proponent of sustainable development, partnered with Growthpoint Properties, South Africa’s largest listed property company, to create a state-of-the art office and warehouse facilities, the outcome was inevitably cutting edge. The offices have a gross floor area of 3 400 m², while the warehouse covers 6 500 m² and has been designed to complement the iconic office building.
Two major challenges were encountered on the project: that of a very sloped site with large amounts of storm water flow during rainstorms, calling for innovative design techniques, and the need to implement Environmentally Sustainable Design (ESD) to the highest standards, including achieving ‘minimal usage of potable water’ status.
The challenging slope of the site was cleverly used to accommodate parking underneath the building, as well as an innovative storm water attenuation facility, resulting in the need for minimal ground works from a fill perspective, overall better space utilisation and faster construction time.
The project’s rainwater harvesting system incorporates Grundfos’ own customised plant for purifying harvested rainwater to drinking water quality. This is believed to be the first implementation in a commercial office and warehouse building in South Africa. The domestic water supply of the building is designed to utilise three different sources of water, namely rain, borehole and municipal water.
With an extensive rain water catchment area, oversized attenuation tank and purification plant the quantity of rain water supplied to the building exceeds the demand for municipal water, except in the dry months of July and August.
To address this shortage, which is weather dependent, the system makes use of borehole water. The building will be supplied with municipal water only in the event of rain and borehole water being exhausted.
With expected zero demand for municipal water supply during the period of October through to May, the design of the rain water harvesting system, incorporating the Grundfos technology for water treatment to drinking quality, considerably contributes to the alleviation of the stress in the bulk potable water supply network.
The office component of the development has since been awarded a 5 Star Green Star SA – Office Design v1 rating by the Green Building Council of South Africa (GBCSA) and is the first industrial facility to be associated with a 5 Star rating in RSA. There are currently 54 Green Star SA certifications in South Africa and Aurecon’s client, Growthpoint Properties, has achieved six of these.