Abstract: The present invention relates to a reflective insulation and radiant barrier intended for use in creating more than one insulating air space in wall cavities formed by parallel structural members attached to the inside of building walls. Specifically, a reflective sheet that is folded to form an insulating panel for positioning between the structural members generally parallel to the building wall, a pair of creases for spreading along the inside surface of the structural members generally normal to the insulating panel, and a pair of tabs for attaching the reflective insulation to the face of the structural members generally parallel to the insulating panel is disclosed. Accordingly, the length of the pair of creases is such that the insulating panel generally bisects the cavity formed by the structural members to create two dead air spaces.