Radiant Barrier

Radiant barriers are reflective materials designed to reduce radiant heat transfer between surfaces, most commonly installed in attics to reflect solar-driven heat away from living spaces below. Unlike conventional insulation that slows conductive and convective heat flow by trapping air in fibrous or cellular materials, radiant barriers work by reflecting up to 97 percent of incoming thermal radiation. The technology was originally developed by NASA for spacecraft thermal protection and was subsequently adapted for building applications. Radiant barriers are particularly effective in hot climates where solar heat gain through the roof is the dominant cooling load. A radiant barrier typically consists of a highly reflective aluminum foil surface bonded to a substrate material like kraft paper, plastic film, or oriented strand board. Installation methods include draping the material across attic rafters, attaching it to the underside of roof decking, or laying it across the attic floor insulation. In hot climates, radiant barriers can reduce attic temperatures by 20 to 30 degrees Fahrenheit and cut cooling costs by 5 to 10 percent. They are most effective when paired with adequate conventional insulation, as the two materials address different heat transfer mechanisms. For interior designers working on renovation projects in warm climates, recommending a radiant barrier installation is one of the most cost-effective comfort improvements available.