A film for use in architectural applications (e.g. for roofs, walls or windows of buildings) comprises a polymeric material and an additive, wherein said polymeric material is a fluoropolymer and said additive is selected from titaniumnitride and tungsten oxide. Preferred polymeric materials may be ethylene chlorotrifluoroethylene (ECTFE) or an ethylene-tetrafluoroethylene copolymer (ETFE).