With their thermal conductivity down to 10 mW/m K, gas-filled panels (GFPs) are regarded as possible high performance thermal insulating solutions for building applications. However, thermal conductivities of respectively 46 and 40 mW/m K have so far been achieved for prototype air-filled and argon-filled panels, values slightly higher than currently traditional building insulation materials. Compared to other high performance thermal insulation materials and solutions, e.g. vacuum insulation panels (VIPs), the future of GFPs may therefore be questioned. Nevertheless, the application of a low-conductive gas and reflective barriers may have a potential in the development of new high performance thermal insulation materials. Within this work, a state-of-the-art review is given on the knowledge of GEPs for building applications today. (C) 2010 Elsevier B.V. All rights reserved.