Abstract: An improved building module suitable for use either in a wall or floor wherein, the module includes a pair of generally parallel side panels interconnected by first and second pairs of end walls to present a space between the side panels. A first tube spans the distance between and is connected to the first pair of end walls and one or more second tubes span the distance between and are connected to the other pair of end walls. The tubes have open ends and the first tube is offset relative to the second tubes. The tubes and side panels can be cut with a hole saw or the like. After the building module has been put in place, electrical wires can be directed through the tubes and to junction boxes placed in holes cut into one or both panels at locations along the length of each tube or at the junctions of two tubes. Tongue and groove means can be provided on the outer peripheral margin of the building module to allow it to mate with and to become coupled to another such building module.