Abstract: An outer skin or facing of wood sheet material and an inner skin or facing of wood sheet material are adhesively bonded to opposite sides of a core of rigid expanded foam material to form an elongated wall unit having a horizontal length greater than its vertical height. A longitudinally extending upper portion of the wall unit incorporates adhesively bonded members which form an integral continuous beam extending horizontally from one end of the wall unit to the opposite end. The integral beam has a vertical height substantially greater than its thickness for supporting a substantial load above a door or window opening which may be subsequently formed within the wall unit at any selected location between the ends of the wall unit. A plurality of spaced wood furring strips are adhesively bonded to the inner facing of the wall unit and are provided with channels adjacent the inner facing for receiving electrical wiring.