Abstract: The building panel of the invention is made in accordance with a novel process. A plurality of frame members are laterally spaced with respect to each other. A particular process is used to form a dry coating of polystyrene disposed on at least one side of each frame member. The frame members are placed in a mold cavity where styrene beads are placed adjacent the dried coating of polystyrene on each frame member. The styrene beads are then expanded through a heating step thereby causing the molded styrene section formed between the frame members to be integrally bonded or fused to the frame members through the mechanism of the expanding stryene beads fusing with the polystyrene of the dried coating.