Abstract: Relatively lightweight precast building panels for use as wall, roof or floor sections are provided. Each panel is molded in a form which is generally rectangular in configuration and provides a cavity into which concrete is poured, the floor of the form being comprised of a plurality of recessed styrofoam inlays separated by wood strips such as furring strips which are also used as a separation between the entire inside perimeter of the form and the styrofoam inlays. After the styrofoam inlays and wood strips are placed, concrete is poured into the form and finished off in the conventional manner. The side walls of the form are removed after the cement sets up and there results a concrete building panel with an adhered styrofoam coating permanently bonded over one surface with wood strips around the perimeter thereof and between each pair of styrofoam inlays.