Short definition
Rough-in is the construction phase where supply lines, drain lines, vents, and gas lines are installed in framed walls and floors before drywall, finish flooring, or fixtures go in. The pipes “rough out” to the future fixture locations as stub-outs. UK plumbers call the same phase “first fix.”
What it is
Sequence on a typical bathroom remodel: framing → rough-in plumbing (and electrical, HVAC) → rough-in inspection → drywall → paint → tile → flooring → second-fix (trim-out) → final inspection. The rough-in phase is the longest plumbing-labor stage, and it’s the one where the most expensive mistakes get made if the inspection is skipped.
Standard rough-in dimensions (see rough-in dimension for the full table):
- Toilet flange: 12 inches from finished back wall (modern standard)
- Bathroom sink supply: 21 to 22 inches above floor
- Tub valve: 28 inches above floor
- Showerhead: 76 inches above floor (preferred for tall users; 72 was older standard)
- Laundry standpipe: 36 inches; shutoffs at 42 inches
A typical 2026 Seattle bathroom rough-in costs $2,500 to $8,000. A whole-house repipe in rough-in stage runs $7,000 to $25,000.
Why it matters to a homeowner
The single most important rule on any permitted plumbing project: never let a contractor drywall before rough-in inspection passes. That’s the inspection point where nail plates, framing-bore limits, pipe support spacing, slope, materials, and pressure tests all get verified. Closing walls before inspection hides non-compliance — and once the walls are closed, the inspector can order them opened back up at the contractor’s expense, but only if it’s caught.
A specific scam pattern worth recognizing: a contractor proposes drywalling before rough-in inspection “to keep the project moving.” That’s either ignorance of the proper sequence or an attempt to bury non-compliant work. Reasonable contractors will not push to close walls before the inspector has signed off.
Pay-staging matters here too. Final payment should never go out before final inspection passes. Progress payments tied to “drywall installed” before the rough-in inspection passed is putting your money against work that may need to be redone.
When you’ll encounter this term
- A contractor’s quote with separate line items for rough-in and trim-out.
- A permit application listing “rough-in” as a scheduled inspection.
- A bathroom remodel timeline where drywall is scheduled after rough-in inspection.
- A pre-purchase report flagging “rough-in issues” — meaning slope, vent, or material problems behind walls.
Common variants and not the same as
- Rough-in vs. finish (trim-out). Rough-in is the in-wall pipework; trim-out / second-fix is the visible fixture install.
- Rough-in vs. underground inspection. Underground is for drains under a slab BEFORE the slab pour. Rough-in is for above-slab piping before drywall. See rough-in inspection stages.
- Rough-in vs. permit-not-required. Like-for-like fixture swaps don’t trigger a rough-in inspection. Adding or relocating a fixture does.
Common failure modes
- Wrong rough-in dimension. Finish fixture won’t fit. Toilet flange at 11 inches when the toilet is 12. Expensive corrective.
- Rough-in inspection skipped. Drywall closed; inspector orders it opened.
- Trim brand changed mid-job. Rough-in valve incompatible with the new finish trim. Order trim before rough-in.
- Stub-outs uncapped. Water turned on; flooded job site.
Washington note
In Seattle, plumbing permits run $132 base plus $26 per fixture (2025 schedule). Like-for-like fixture replacement in the same location does not require a permit; any layout change or new fixture does. The homeowner exemption (RCW 18.106.150) lets you DIY plumbing in your own owner-occupied home, but you still need permits and inspections for major work. Tacoma, Bellevue, Olympia, Everett, and Spokane each run their own permit programs with similar fee structures.