This paper discusses the use of gas-filled panel technology as a high-performance, non-CFC insulation for building applications. Gas-filled panels (GFPs) combine low-emissivity surfaces and multiple, low-conductivity gas-filled cavities to minimize radiation, convection, and conduction. The thermal performance of some GFP designs has been independently tested (ASTM 1989) at a national laboratory. Measurements on first-generation prototypes yielded R-5.2/in. (5.2 h.ft2.?F/Btu.in. [36 m.K/W]) with an air fill, R-7.1/in. (49.3 m.K/W) with an argon fill, and R-12.5/in. (86.8 m.K/W) with a krypton fill. This paper discusses technical aspects of GFP barrier materials and their gas transmission rate requirements, baffle component characteristics, and potential gas fills. We present examples of potential GFP products for various building applications with cost and performance estimates.