Future requirements for architecture and civil engineering

From an economic view, ETFE-foils are to be assessed positively. The production costs of foils are relatively low. Due to their self-cleaning surface properties, maintenance costs in the form of cleaning of the building envelopes are lower compared to glass. The energy costs for the stabilising pressures of pneumatic foil cushions are also relatively low due to the low pressures (ETFE-foU cushions constitute a low pressure system with pressures usually lower than 1000 Pa). 

From an ecological perspective, sustainabihty of a construction method will certainly be of central importance in the future. What environmental 

building envelopes and structural elements have to take on a variety of central functions. They determine the energy consumption and fundamentally dominate the overall impression of a building from a design perspective. In terms of the functional and architectural requirements of the building envelopes, ETFE-foils offer interesting application possibilities. 

From a building-physics perspective, the high transmissibility of the entire radiation spectrum is of fundamental importance. As already explained, the especially high transmissibility of the UV spectrum is already specifically utilised. Due to the high transmissibility of radiation, durability and selfcleaning surface properties, ETFE-foils are especially suited for the generation of solar energy. The first tests with flexible photovoltaic cells placed between two ETFE-foil layers have already been done. 

From a creative, engineering point of view, the feasible forms and maximum spans of ETFE-foil constructions are decisive factors which will determine the further success of this construction method. ETFE-foils possess positive load-bearing behaviour which is characterised by material and geometrical nonlinearities. The ground plan shapes, realisable to almost any desire, offer the architect a multitude of design possibilities. Spans of ETFE-foil constructions can be enlarged through support measures like 

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