Rough-in work gets bid per fixture because it’s the one unit that scales with the job. Counting fixtures is fast, a builder understands it, and it travels between houses in a way that square footage does not.
What people want when they search plumbing rough-in cost per fixture is a dollar figure. We aren’t going to print one, and it’s worth saying why: that number swings enormously by region, by labor market, by whether it’s slab or crawlspace, by PEX or copper, and by whether you’re a one-truck shop or carrying a yard and a crew. Any national average you read is somebody else’s cost, and bidding off it’s how shops end up busy and broke.
What’s useful is the method. Here’s how to build your own.
What counts as a fixture
A fixture is a point that needs supply, drain, or both. Agree on the count before you price, because this is where bids diverge from each other.
- Toilet, lavatory, tub, shower, kitchen sink, laundry box, hose bib, floor drain.
- A tub and shower combination is normally one fixture. A separate tub and a walk-in shower are two.
- Water heater, softener loop, and the main service are usually priced separately rather than counted as fixtures.
Write your definition on the bid. When the other bidder counted fifteen and you counted eighteen, the builder needs to see why.
The three phases a fixture price has to cover
Per-fixture pricing usually spans all three, which is why it looks high at first glance.
- Underground. Sleeves, the drain and vent below slab, inspection before the pour.
- Rough-in. Drain, waste and vent in the walls, supply lines, nail plates, test and inspection.
- Trim. Setting the fixture, stops, supplies, trim kits, final test.
If you quote a per-fixture number for rough-in only and the builder assumed it included trim, you’ve lost the difference and the relationship.
Building your own number
Do this once off your own completed jobs, not off a forum post. Pull three finished houses of similar construction.
- Count the fixtures on each, using the definition you just wrote down.
- Total the labor hours that went into each house across all three phases. Real hours from timesheets, including the trips back for inspection.
- Total the material at what you paid, not what you quoted.
- Divide both by the fixture count to get hours per fixture and material per fixture.
- Apply your fully loaded hourly rate to the hours, your markup to the material, and add profit on top.
As arithmetic rather than advice: if three houses average eleven fixtures and sixty-six labor hours, that’s six hours per fixture. At your own loaded rate, plus your own material per fixture, plus your markup and profit, you’ve a number that’s true for your shop. Do not borrow the six. Count yours.
What makes the number move
- Slab versus crawlspace versus basement. Underground work in a slab is a different job with a different inspection.
- Material. PEX manifold, PEX home run, and copper aren’t the same labor.
- Fixture grouping. Two baths stacked back to back are cheaper per fixture than two baths at opposite ends of the house.
- Ceiling height and framing. Open web trusses versus solid joists changes how long the DWV takes.
- Who you’re working for. A builder who schedules well and pays on time costs you less than one who does not, and that belongs in the price.
Re-check it every year
A per-fixture price built two years ago is carrying two-year-old material cost and a labor rate from before your last raise. Recount from recent jobs at least annually, and any time your crew or your supplier pricing changes materially. The same discipline that keeps a plumbing price book current applies here.
A note on scope
BidRise prices from the numbers you give it. It doesn’t do takeoffs from a plan set and it won’t count fixtures off drawings for you. For residential service and replacement work it writes the estimate while you talk, and the method above is how you decide what goes in it. If you’re bidding new construction off plans, this guide is the useful half and the app isn’t the tool.
For pricing day-to-day service work, the shorter path is how to bid a plumbing job.