Abstract: A unique one-piece molded insulating and drainage panel for use for basement subterannean walls is disclosed. The panel is molded from expanded polystyrene having very low water permeability. When installed, the panel has two sides having vertically oriented grooves on both sides. The grooves abutting the foundation wall are typically rectangular whereas the vertical channels on the outside wall are specifically designed to be self-clearing to avoid blockage by backfill. Typically a bell-bottom shaped narrow opening and a wider inner channel is used.

Abstract: A unique wall panel is constructed from expanded polystyrene beads in an expanded polystyrene mold with structural members embedded in it during the molding process. The structural members are in the form of two by four studs placed at sixteen inch centers. Adjacent panels have interlocking grooves and ridges which fit together. The advantage of the present invention is that a total insulated wall is created with no cracks or spaces in the insulation. These lightweight panels can be carried to the building site, where base and top plates are applied and the panels interlocked to form a perfectly insulated wall.