Once the shell is finished, siding and roofing can be installed. At the same time, the electrical and plumbing contractors start running pipes and wires through the interior walls, ceilings, and floors. Sewer lines and vents, as well as water supply lines for each fixture, are installed. Bathtubs and one-piece shower/tub units are put in place at this point because there’s more room to maneuver large, heavy objects.
After the roofing goes on, the house is considered “dried in.” An electrician then installs receptacles for outlets, lights, and switches, and runs wires from the breaker panel to each receptacle. Wiring for telephones, cable TV, and music systems is included in this work.