An extruded composite utilized as a building material includes a base polymer, unseparated processed recycled carpet waste, and a filler material, which may be a wood filler or other natural fiber. The recycled carpet waste may be used to decrease the amount of both base polymer and wood filler to achieve an equivalent product at lower cost. The extruded composite may also utilize chemical foaming agents to reduce density. Both foamed and non-foamed composites may be capstocked.