The invention concerns a component for building wall elements or the like, comprising a cuboidal base element that has one or more grooves at least in one part of its periphery. One implementation involves determining a performance cost in deploying the virtual appliance to different pairings of candidate host and storage subsystems. The nozzle is positioned in a mixing chamber adjacent to an inlet coupled to a source of dry polymeric material. Actuatable means mounted on the frame are provided for displacing the axle between a first raised position and a second lowered position; also provided are means for actuating the actuatable means to permit the actuatable means to raise and lower the auxiliary axle as desired.