The Unilever Head Office is located in an exposed position directly on the banks of the River Elbe. Around 1,000 staff members work here in the 25,000 square meters of space. Alongside the holistic lighting and energy concept, the other thing that catches the eye, even from afar, is the polygonally folded curtain shrouding the building in 6,200 square meters of ETFE foil. The engineers at Radolfzell-based formTL designed this wind-protection of single-layer ETFE foil on a unbending frame, shaping, load-bearing stainless steel guy ropes, and a transparent Textlon-brand ETFE foil made by Vector Foiltec. The curtain protects the solar protection blinds behind it - ensuring they can be used on sunny days when the wind nevertheless blows strong.
Ethylene tetrafluoroethylene (ETFE) is an extremely resilient plastic foil, low in weight but high in light permeability. It ages very slowly, and its service life is about 25 years. The overall structure generates low surface tension meaning that dirt is hardly able to settle firmly on the foil and instead gets washed away by the rain. When the wind blows, the foil oscillates slightly, such that the building does not have the hard-edged feel so typical of glass facades.
The transparent skin gives the building an open and light touch. Moreover, reminiscent of the sails of old schooners, it also testifies to the location's former function.
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