The metalized surface creates an R-2 thermal resistance in the wall cavity when facing a minimum ¾-inch air space. DuPont weatherization systems are part of the Energy Star home sealing labeling program. Builders who use DuPont Tyvek ThermaWrap can earn up to 2 points toward certification to the NAHB National Green Building Standard , and may also contribute toward U.S. Green Building Council LEED certification points. Homeowners may also qualify for an energy tax credit through their use.