Potential and limitations for ETFE‐foils in pneumatically retractable structures

Abstract Rising urban temperatures due to the urban heat‐island effect increase the demand for multifunctional, lightweight façade and roofing systems that span large areas and enable adaptive envelope functions – such as shading and ventilation – to improve climate resilience. Membrane materials are promising in this context due to their low weight and effective material use. While most retractable membrane structures today employ coated fabrics, a newer approach uses multilayer ETFE‐structures with deformable framework systems to create pneumatically retractable ETFE‐structures. In such systems, retractability is achieved by adjusting the internal pressure, which induces a controlled in‐plane deformation of the deformable framework system. This contribution outlines the potential and limitations of pneumatically retractable ETFE‐structures. ETFE‐foils are inherently transparent, printable for tailored solar control and proven in pneumatically prestressed cushion structures. However, reliable operation requires careful consideration of the material‐structure‐interaction and framework design, while the multiaxial behaviour, long‐term creep under application‐specific durations and the sensitivity to creasing/folding must be considered for the foil component.