3. Complete Rough-in Plumbing, Electrical and HVAC
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During this stage, the following items are installed:
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Pipes and wires
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Sewer lines and vents
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Water supply lines
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Bathtubs and shower units
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Ductwork for HVAC system
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HVAC vent pipes
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Electrical wiring and receptacles
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.
Ductwork is installed for the heating, ventilation, and air conditioning (HVAC) system, and possibly the furnace. HVAC vent pipes are installed through the roof, and insulation is installed in the floors, walls, and ceilings.
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.
Note that HVAC ducts and plumbing are usually installed before wiring because it’s easier to run wires around pipes and ducts than vice versa.
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Cost Breakdown.
Installing rough plumbing in an entire home can cost anywhere from $8,000 to $12,000, or an estimated cost of $4.50 per square foot for new construction.
The national average to wire a new home can be anywhere from $3,269–$6,084 for a 1,000-square-foot house.
Installing an HVAC system with ductwork can cost $7,000 to $16,000, but add-ons can bring this range up to $13,000 to $17,000.
Timeline.
While HVAC may only take three to seven days to install, the rest of the mechanicals, from plumbing to electrical, can take two to four weeks. This step shouldn’t be rushed, because getting stuck in inspections can draw out construction even longer and prevent the project from moving forward.