this building component includes a peripheral sidewall and upper and lower walls forming a casing ; a core of shredded waste material and an exterior plastic skin covering the casing . the method of making the component includes the steps of filling a peripheral form with shredded waste material , closing the form at the upper and lower ends incorporating it into the component by applying a reinforced plastic binder over the closed form . a modified component has a rectangular casing formed from structural members and is provided with a braced interior core .