Circularity of Ethylene Tetrafluoroethylene Foils in Architecture: Evaluating Post-Consumer Recycling Through Life Cycle Assessment

Ethylene tetrafluoroethylene (ETFE) foil is an ultralightweight fluoropolymer membrane covering large-span structures, yet the environmental impacts of its recycling remain largely unquantified. This study assesses an experimental recycling pathway in which 2235 kg of post-consumer ETFE foil, recovered from the Chelsea and Westminster Hospital in London after 33 years, was cleaned, agglomerated, pelletised and extruded into foil with 100% recycled content. The life cycle assessment follows ISO 14040/14044, applies EN 15804+A2 and the cumulative energy demand, and adopts an end-of-life-to-gate boundary under the cut-off approach, with 1 kg of recycled foil as the functional unit. The calculated material yield, based on adopted process-loss values, is 93.7%. Producing 1 kg of recycled foil results in a fossil global warming potential of 3.33 kg CO2 eq. and a cumulative energy demand of 64.1 MJ, of which 80% is non-renewable. Pelletisation, agglomeration electricity, road transport from London to Bremen and foil extrusion account for 70% of the fossil global warming potential. Scenario analysis, dominated by the proxy datasets for pelletisation and extrusion, yields a GWP-fossil range of 2.63–5.17 kg CO2 eq. These values are lower than those published for the GWP of virgin ETFE foil (12.0–20.9 kg CO2 eq.), highlighting the promising environmental potential of closed-loop recycling, which a harmonised comparison would confirm.