New construction plumbing in Knoxville, TN runs in three stages: underground and rough-in drains and water lines before the slab or subfloor, top-out through the framing before insulation, and trim once cabinets and tile are finished. Each stage is inspected, and the city plumbing permit fee is $55 plus inspection.
Updated October 2026
Plumbing on a Builder's Schedule
On a new build, plumbing happens in pieces between other trades, and missing a window holds up everyone behind it. Underground work has to pass before the slab is poured, top-out before insulation, and trim after countertops. We schedule each stage with the builder and show up when the framing is actually ready.
We work from the plans and fixture schedule, pull the permit, and coordinate the water service, sewer or septic connection and gas lines. For business spaces, see commercial plumbing; for a new bath in an existing home, bathroom remodel plumbing.
What New Construction Plumbing Costs Depends On
Priced from the plans and the fixture count.
More bathrooms and fixtures mean more pipe and labor.
A slab means underground plumbing before the pour.
Tap, meter, sewer or septic connections.
Piping to appliances and the water heater.
The city fee is $55 plus inspection.
Rough-In
Rough-in covers the drains, vents and water lines that sit under the slab or subfloor and inside the walls, set to the fixture positions on the plans. On a slab, underground drains are laid, tested with water or air, and inspected before the pour. Over a crawlspace, the building drain and branches run under the joists. Stub-outs are set at the heights the chosen fixtures require, which is why a fixture schedule early in the job prevents moving pipe later. Everything stays capped and tested until the next stage.
Top-Out
Top-out finishes the piping through the framing: vent stacks through the roof, water lines to every fixture, tub and shower valves set, and the water heater location plumbed. The whole system is pressure-tested and inspected before insulation and drywall cover it. This is where coordination matters most, since electricians, HVAC installers and framers all work in the same walls. We protect pipe from nails with plates where it passes through studs, and confirm tubs and shower bases are set before the walls close.
Trim and Final
Trim comes after cabinets, countertops and tile: toilets set, faucets and sinks mounted, shower trim installed, the water heater started, appliances connected, and every fixture tested for flow and leaks. The final inspection follows. We walk the building with the builder, clear the punch list, and make sure the owner or tenant knows where the main shutoff and the water heater controls are before the keys change hands. A clean final is what lets the certificate of occupancy move forward.
What Our New Construction Plumbing Covers
- Plan review and fixture schedule
- Permit pulled for each project
- Underground drains tested before the pour
- Rough-in and top-out with pressure tests
- Water heater and gas lines plumbed
- Trim, fixtures and appliance hookups
- Final inspection and walkthrough
Which Water System a New Knoxville Lot Connects To
Framing ready? Get the rough-in on the schedule.
(865) 344-9122From Plans to Final Inspection
- 1
Review plans
Fixture schedule and routes confirmed.
- 2
Underground
Drains laid and tested before the slab.
- 3
Rough-in and top-out
Drains, vents and water lines through the framing.
- 4
Inspections
Each stage inspected before it's covered.
- 5
Trim and final
Fixtures set, system tested, final inspection.
New Construction Plumbing Questions From Knoxville Homeowners
Do you work for builders and homeowners?
Yes, on custom homes, additions and tenant spaces.
When should the plumber be scheduled?
Before the foundation for underground work, then at framing and again after finishes.
Can you work from our plans?
Yes. An early fixture schedule prevents moving pipe later.
Do you pull the permits?
Yes, and we schedule each inspection.
PEX or copper for new construction?
Most new homes use PEX; copper remains an option where preferred.
Do you handle the water heater and gas?
Yes, including gas piping sized for every appliance.
Other Commercial Jobs We Handle
Kitchen Plumbing Remodel
Island sink drain and vent and pot filler line.
Kitchen Plumbing Remodel in KnoxvilleTankless Water Heater Installation
Gas line upsizing and venting and condensate.
Tankless Water Heater Installation overviewPlumbing Winterization
Crawlspace pipe insulation and hose bib shutoffs.
Plumbing Winterization detailsBuilding in the Knoxville area?
Call to schedule the plumbing for your next project.