Cost Guides
Plumbing Rough-In Cost 2026: New Builds, Additions and Remodels
Per-fixture and per-square-foot rough-in pricing, PEX vs copper material costs, and why moving a toilet three feet costs more than adding a sink.
What 'rough-in' includes
Rough-in is everything behind the walls: supply lines, drain-waste-vent (DWV) piping, and the stub-outs each fixture connects to. It ends at inspection, before drywall. Finish plumbing — setting the toilet, hanging the faucet, connecting the disposal — is a separate line, typically 20–30% of the plumbing budget.
Plumbers price rough-in per fixture, because each fixture means supply, drain and vent, not per foot of pipe.
Per-fixture rough-in cost, 2026
| Fixture | Rough-in cost | Finish set | Notes |
|---|---|---|---|
| Toilet | $450 – $900 | $150 – $350 | 3 in drain, wet-vented where allowed |
| Lavatory sink | $400 – $800 | $150 – $400 | Simplest fixture to add |
| Kitchen sink + disposal | $550 – $1,100 | $200 – $500 | Disposal needs a dedicated circuit |
| Bathtub | $700 – $1,400 | $250 – $600 | Access panel strongly recommended |
| Shower (standard) | $700 – $1,500 | $250 – $700 | Pan and drain critical |
| Shower (multi-head / body sprays) | $1,400 – $3,000 | $600 – $1,800 | May require 3/4 in supply |
| Washing machine box | $400 – $800 | $100 – $200 | Add a pan on upper floors |
| Water heater connection | $500 – $1,200 | $300 – $900 | Tankless adds gas or 240V work |
| Hose bib / exterior spigot | $250 – $600 | — | Frost-free type in cold climates |
| Gas line run | $350 – $900 | — | Per appliance, typical run |
Whole-project pricing
For new construction and additions, plumbers often quote per square foot or per bathroom as a sanity check against the fixture count.
| Scope | Typical cost |
|---|---|
| New build rough-in | $4.50 – $9.00 / sq ft |
| Full bathroom (3 fixtures), same location | $2,000 – $4,500 |
| Full bathroom, fixtures relocated | $3,500 – $8,000 |
| Kitchen remodel, sink stays put | $800 – $2,000 |
| Kitchen remodel, sink moves to island | $2,500 – $6,500 |
| Whole-house repipe (PEX, 2 bath) | $4,500 – $12,000 |
| Whole-house repipe (copper, 2 bath) | $9,000 – $22,000 |
| Sewer line replacement | $3,500 – $15,000 |
Why moving a toilet costs more than adding a sink
A lavatory drain is 1.5 or 2 inches and can often tie into existing waste with minimal work. A toilet needs a 3-inch drain at a minimum 1/4 inch per foot slope, and that slope has to be found somewhere — usually by cutting the floor, and on a slab foundation by cutting and re-pouring concrete.
Slab cutting is what turns a $600 fixture move into a $4,000 one: saw-cutting, excavation, pipe, backfill, patch and often a structural check on post-tension slabs, which cannot be cut at all without engineering.
- Slab-on-grade toilet relocation: $2,000 – $5,000
- Joist-floor toilet relocation: $600 – $1,800
- Post-tension slab: engineering required before any cut
PEX vs copper in 2026
PEX-A and PEX-B dominate residential new construction because material costs are roughly a third of copper and installation is dramatically faster — fewer fittings, home-run manifolds, no torch in a framed wall. Copper still wins on UV exposure, high-temperature applications and resale perception in some markets.
| Material | Material $/ft | Installed $/ft | Lifespan | Notes |
|---|---|---|---|---|
| PEX-B | $0.40 – $0.90 | $2.50 – $5.00 | 40–50 yrs | Cheapest, crimp/clamp fittings |
| PEX-A | $0.70 – $1.40 | $3.00 – $6.00 | 40–50 yrs | Expansion fittings, full-bore |
| CPVC | $0.50 – $1.10 | $2.50 – $5.50 | 40–50 yrs | Brittle with age, solvent weld |
| Copper type L | $3.50 – $7.00 | $8.00 – $16.00 | 50–70 yrs | Best longevity, highest cost |
Permits and inspection
Rough-in plumbing requires a permit and a pressure test inspection in essentially every US jurisdiction. Drywall cannot legally go up until that inspection passes. If a contractor suggests skipping it, understand that you inherit the liability, the insurance problem and the disclosure obligation at sale.
Tools & guides for this project
Material Cost Calculator
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Waste Factor Calculator
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Project Budget Calculator
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Labor Cost Calculator
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