Plumbing encompasses the water distribution system, sewage disposal system, and heating/cooling piping in a building. The installation occurs in three stages: first, the service entrance provisions are made during foundation work; second, rough-in plumbing is completed before wall and floor finishes; and third, finish plumbing involves installing fixtures after the structure is completed. Common materials for water distribution pipes include copper and plastic, with plastic varieties like PVC and PEX gaining popularity for their versatility. HVAC technicians handle climate control systems, including ductwork installation and system fine-tuning, while building codes dictate pipe types, fixture requirements, and testing procedures