01. Aug 2018

Rotunda: Metallic fabric as effective solar protection

South African architecture firms GLH and Terra Ether selected OMEGA metal fabric from GKD – GEBR. KUFFERATH AG for the distinctive rotunda at the main entrance of the new headquarters of Statistics South Africa in Pretoria (Stats SA). The façade cladding, decorated with over half a million buttons, offers effective solar protection and fulfills the exacting Green Building requirements. Thanks to the elasticity of the cable mesh fabric, it traces the shape of the rotunda seamlessly.

The HQ of the National Statistical Office provides over 31,800 square meters office space for 3,500 employees. Like a gigantic drum with five fingers, the building complex, which was awarded four stars by the Green Building Council South Africa (GBCSA), blends in harmoniously with the surrounding environment. The glazed rotunda at the main entrance was covered with a visually seamless shell made of metal fabric from GKD. A total of 41 panels of different widths, each measuring 10.14 meters in length, were wrapped around the building to give it the appearance of a drum. In African culture, the drum is considered an invitation to communicative cooperation. The metallic membrane not only makes a key contribution to fulfillment of the Green Building requirements, but also serves as effective solar protection for the fully glazed façade. The fabric reduces solar input into the building, while at the same time significantly reducing the heating up of the façade. This interaction leads to considerably reduced air conditioning costs. At the same time, the woven shell grants employees at the National Statistical Office unrestricted views out of the building thanks to its high degree of transparency. Another plus point of the stainless steel fabric with regard to the client’s exacting sustainability goals was the fact that it can be almost entirely recycled at the end of its useful life. However, the flexible tensibility of the woven texture is ultimately what gave the key impetus for use of the textile membrane. This makes it possible for the façade cladding to trace the form of the rotunda in a visually seamless way, thereby creating the impression of a drum. As an additional visual highlight, some 500,000 stainless steel buttons of varying sizes were applied to the building shell as a symbolic image of the authority. Following a design by Marius Botha, the shimmering metallic buttons, some of which were left untreated and some of which were coated in a bronze color, were fixed in place on the façade by hand by countless local workers. This presented GKD with the additional challenge of first aligning the specimen transitions and then fixing them in place precisely on the curved panels using tailor-made clamps.