Plumbing Rough-In Cost: What Contractors Charge and Why
Plumbing rough-in costs $1,500–$8,000+ depending on scope, fixture count, and whether walls are open. Here's the full breakdown — what rough-in includes, what moves the price, and how to vet bids.
Plumbing rough-in is one of those line items that catches homeowners off guard — the work is invisible (literally inside walls), but it's load-bearing for everything that comes after. A bad rough-in means failed inspections, opened walls, and rescheduled finish work. Here's how to understand the cost and what you're actually paying for.
Rough-In Cost by Scope
| Scope | Typical Cost Range |
|---|---|
| Single bathroom addition (new construction) | $1,800–$3,500 |
| Bathroom remodel — no relocation | $800–$2,000 |
| Bathroom remodel — fixtures relocated | $2,500–$5,500 |
| Kitchen remodel — sink stays in place | $500–$1,500 |
| Kitchen remodel — sink relocated | $1,500–$4,000 |
| Laundry room addition | $1,200–$2,800 |
| Full addition (bath + kitchen rough-in) | $5,000–$12,000+ |
| Slab penetration (moving drain in concrete) | $1,500–$4,500 additional |
What Rough-In Includes
Supply lines: Hot and cold water pipes from the main supply running to stub-outs at each fixture location. Modern construction uses PEX tubing (flexible, freeze-resistant, easy to run) or copper. PEX is significantly cheaper to run — a major reason plumbing costs have come down in the last decade.
Drain, waste, and vent (DWV) lines: The drain system — ABS or PVC pipe — that carries wastewater from each fixture to the main stack. This includes vent pipes that run up through the roof to equalize pressure. DWV is almost always the most labor-intensive part of a rough-in because pipe sizing, slope, and vent configuration are code-specific.
Stub-outs: Short pipe sections that extend through walls or floors at each fixture location, capped during rough-in and later connected during finish plumbing. Each stub-out location must be precise — toilet flanges, shower drain locations, and sink drain locations are hard to move after drywall.
Inspection: Most jurisdictions require a rough-in inspection before walls close. Your plumber should be familiar with local code and schedule the inspection as part of the job. Never close walls before the inspection sign-off.
What Moves the Price
Fixture count: Each fixture (toilet, sink, shower/tub, dishwasher, laundry) adds supply and drain lines. A 3-fixture bathroom (toilet, sink, shower) costs significantly less than a 5-fixture master bath (toilet, double sink, shower, tub, bidet).
Distance from main stack: The farther the new fixtures are from the main drain stack, the more pipe and labor required. A bathroom addition on the opposite side of the house from the main stack can require routing drain lines through multiple floor cavities or exterior walls.
Access: Finished ceilings and walls below the work area must often be opened to run drain lines. A first-floor addition requiring drain lines run through a finished basement ceiling is more expensive than running new lines in an unfinished space.
Slab vs. above-slab: First-floor bathrooms (or any bathroom over a concrete slab) require cutting the slab to run drain lines. This adds $1,500–$4,500 depending on how much concrete must be removed and patched. Above-slab work (second floor, basement with wood subfloor) is significantly cheaper.
Pipe material: PEX supply lines are the current standard — faster to install, cheaper than copper, and more forgiving. Copper is still used in some high-end projects or where local codes require it. If your house has galvanized supply lines and you're doing significant plumbing work, a licensed plumber may recommend replacing sections. Budget for this possibility in older homes.
Reading a Plumbing Bid
A complete rough-in bid should specify:
- Number of fixtures included (toilet, shower, sink — listed individually)
- Pipe material (PEX, copper, ABS, PVC)
- Whether the bid includes permit and inspection fees
- What's NOT included (finish fixtures, connection to fixtures, appliance hookup)
- Whether concrete cutting is included if slab work is required
Be cautious of bids that don't break out fixture counts — this makes change orders easier to justify. If the bid says "bathroom rough-in: $2,800" without listing what's included, ask for a line-item breakdown before signing.
How to Vet Plumbers
A plumber doing rough-in work should hold a Master Plumber license (required in most states for any work that touches supply or sewer connections). Verify the license at your state contractor board — it takes two minutes and is non-negotiable.
Ask for proof of general liability insurance. Plumbing failures in walls cause water damage — insurance protection is essential.
Get 2–3 bids. The range on plumbing rough-in is wide. A $1,000 spread between two bids on a $3,000 job is normal — a $3,000 spread should trigger questions about scope differences, not just price shopping.
For homeowners doing their own pre-inspection prep or minor rough-in connections, SharkBite push-to-connect fittings are approved for use inside walls and underground, require no soldering, and allow quick connection changes if a plumber needs to modify the layout.
Related: How to Read a Contractor Bid · Bathroom Addition Cost · Renovation Budget Calculator
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Written by BlueprintKit
BlueprintKit publishes expert construction and renovation content based on real project experience. Every guide is reviewed by a licensed general contractor.