n. The pipes, fixtures, etc., necessary for the flow of water to a building, and flow of sanitary waste from a building. In days gone by, the art of casting and working in lead, and applying it to building purposes; especially, the business of furnishing, fitting, and repairing pipes for conducting water, sewage, etc. The pipes, copper or plastic, and other apparatus, used in conveying water, sewage, etc., in a building.