The “Siemens Group Headquarters” project in Munich, which has an office atrium roofed over with air-filled membranes, is a good example of sustainable building with ethylene tetrafluoroethylene, or ETFE for short.
The three air-filled chambers of the four-layer foil elements, manufactured and installed by seele cover, improve the thermal insulation effect significantly. And with printing on the uppermost membrane layer, the build-up of heat in the atrium due to solar radiation in the summer is also reduced. With its high total thermal resistance, the ETFE material therefore represents an efficient way of preventing high energy losses. The pneumatic ETFE systems also attenuate and absorb the effects of the wind and are low-flammability products (class B-s1d0 fire rating) with a self-extinguishing effect. The foil has an anti-adhesive surface and so is self-cleaning because dust and dirt hardly sticks to it – and any that does is simply washed off by rainwater. The design life of an ETFE roof is about 25–30 years and the foil can be fully recycled.
This special membrane roof and its delicate supporting structure reduce the overall weight. That in turn has a positive effect on the cost of fabricating the membrane structure due to the reduced consumption of material. Compared with other systems, that means a further increase in energy efficiency.