Expansion of the headquarters of the Würzburg Chamber of Commerce and Industry in 2003 gave it more room for training. Transparency and light were the basic design elements in the concept of the architects GÖG/Redelbach. Accordingly, they covered the newly created courtyard of the annex with three light funnel-shaped membrane screens that have a transparent effect.
The square screens, which are made of a single layer of ETFE fabric, offer protection against the elements for the plethora of events held in the courtyard. The fabric structure of the membranes meets the high standards for light permeability and the requirements for fire protection classification DIN 4102-B1. The three screens set at different levels, with side lengths of 11, 12.5 and 14 metres, cover a total area of 480 m2, while maintaining a light and filigree appearance. One advantage of the funnel shape is that rainwater is diverted inside the supports, making additional drainage systems unnecessary.
The screens’ supporting structure comprises fixed steel supports and attached cantilevered beams. The load is carried via the fixed supports through the ground floor ceiling to the subterranean parking garage under the courtyard, where it is borne by the foundation plate. To absorb the tensile forces, integrated tensile structures support the transparent ETFE fabric cover. Each of the tensile structures, consisting of radial and ring cables, is friction-locked using plate-like couplers.