19 prefabricated non-metal room units for structurally engineered prefabricated non-metal buildings; non-metal building parts, namely, windows, window sills, doors, door frames, partition walls, outer walls, panel and cover elements for facades, venetian blinds, roller blinds, sunshades, roofs, gutters, stairs, staircases, landings, banisters, false ceilings, floor tiles, pipes and plumbing