Rough-In Plumbing Cost: New Construction
The rough in plumbing cost new construction buyers and builders should budget in 2026 is $4,500 to $12,000 for a typical single-family home, with most standard three-bedroom, two-bathroom houses landing between $6,000 and $9,000. Rough-in is the phase of plumbing where all the supply lines, drain lines, and vent pipes are installed inside the walls and floors before drywall goes up, and it is one of the largest single plumbing expenses in a new build. The final number depends on the number of fixtures, the number of bathrooms and kitchens, the size of the house, the pipe material, and local labor rates. A small one-bathroom home can rough in for as little as $3,000, while a large custom home with four or more bathrooms, a laundry room, and a wet bar can exceed $20,000. Understanding what rough-in includes and how it is priced helps you read a builder's bid, spot missing scope, and avoid change orders that blow up your budget mid-build.
Average Rough-In Cost
National averages for rough-in plumbing in new construction cluster around $7,000 for a mid-size home, but the range is wide. A small home under 1,200 square feet with one bathroom runs $3,000 to $5,000. A typical 1,500 to 2,500 square foot home with two bathrooms and a kitchen runs $5,000 to $9,000. A larger home of 3,000 to 4,000 square feet with three or four bathrooms runs $9,000 to $15,000. Luxury homes over 5,000 square feet with multiple kitchens, wet bars, and specialty fixtures can reach $20,000 to $30,000. These figures cover labor and materials for the rough-in phase only: the pipes, fittings, valves, and the labor to install them, plus the pressure test and inspection. They do not include the water service line from the street, the sewer or septic connection, fixtures such as toilets and faucets, or the finish plumbing phase. Labor accounts for 60 to 70 percent of the rough-in cost, so regional wage differences matter: rough-in labor in California or New York can run 30 to 50 percent higher than in the Midwest or South. For a full overview of plumbing pricing across a build, see our plumbing costs hub.
What Rough-In Plumbing Includes
Rough-in is everything hidden behind the walls. It starts with the main water supply lines running from the water meter or well to a manifold or trunk line, then branching to every fixture location. Drain lines and vent stacks are installed for every sink, toilet, tub, shower, and appliance, with proper slope so wastewater flows by gravity: drains need a quarter inch of fall per foot, and getting the slope right is one of the most skill-intensive parts of the job. The plumber installs water supply stub-outs and drain stub-outs at each fixture location, capped and ready for the finish phase. Gas lines are roughed in too if the home uses gas for the water heater, stove, or furnace. The water heater connections are roughed in, and the main shutoff valve, pressure regulator, and hose bibs are installed. Once the piping is in place, the system is pressure-tested with air or water and inspected by the local building department before the walls are closed. If the inspection fails, the plumber fixes the problem and calls for a re-inspection, so the rough-in phase is not complete until it passes.
What rough-in does not include is just as important to understand. Fixtures themselves, toilets, sinks, tubs, showers, faucets, and showerheads, are part of the finish phase and are priced separately, often as an allowance in the builder's contract. The water service line from the street to the house is usually a separate line item, and the water line installation cost can add $1,500 to $5,000. The sewer lateral or septic system connection is also separate. Appliances such as dishwashers and washing machines are connected during finish, not rough-in. When you compare builder bids, make sure each one defines rough-in the same way, or you will be comparing different scopes.
Cost Per Fixture
Plumbers often price rough-in by the fixture, which makes it easy to estimate a job from a floor plan. A standard bathroom rough-in, including a toilet, a sink, and a tub or shower, costs $1,500 to $2,500. A half bathroom with just a toilet and sink runs $800 to $1,500. A kitchen rough-in, including the sink, dishwasher, and refrigerator water line, costs $1,000 to $2,000. A laundry room with a washer hookup and a utility sink runs $600 to $1,200. A wet bar adds $500 to $1,000. Individual fixture rough-ins break down roughly as follows: a toilet costs $300 to $500, a bathroom sink $250 to $450, a bathtub $400 to $700, a shower $400 to $800, a kitchen sink $400 to $700, and an outdoor hose bib $150 to $300. These per-fixture figures include the supply lines, drain, vent, and labor for that fixture only. Fixtures that are far from the main stack cost more because they need longer pipe runs and additional venting. A bathroom on the opposite side of the house from the main drain stack, or a second-floor bathroom above an unconditioned space, will cost more than one stacked directly above the first-floor bath.
Rough-In vs Finish Plumbing
Rough-in and finish are two distinct phases with separate pricing, and confusing them is the most common budgeting mistake in a new build. Rough-in is the hidden work: pipes inside walls and floors, installed before drywall. Finish plumbing, also called trim-out, happens after drywall, paint, and flooring are done: the plumber returns to install the toilets, sinks, faucets, showerheads, and appliance hookups, and to test everything. Finish plumbing typically costs $2,000 to $5,000 for a standard home, depending on the quality of the fixtures, and the fixtures themselves can cost $2,000 to $10,000 or more as an allowance. Together, rough-in and finish usually total $8,000 to $20,000 for a typical new home, which is why a builder's plumbing allowance should be read carefully. If the allowance seems low, ask what it covers: a $5,000 plumbing allowance that only covers rough-in leaves you paying for finish and fixtures out of pocket.
What Affects the Price
Several factors move rough-in cost beyond the fixture count. The number of stories matters: a two-story home needs longer vent stacks and more complex drain routing than a single-story home, adding 10 to 20 percent. The foundation type matters too: slab foundations require all drain lines to be installed before the concrete is poured, which is unforgiving of mistakes and can add cost, while crawl space and basement foundations allow easier access and future changes. Pipe material is a factor: PEX is the cheapest and fastest to install, copper costs 30 to 50 percent more in material and labor, and CPVC sits in between. The layout matters: bathrooms stacked vertically share a drain stack and a vent, which is cheaper than bathrooms spread across the floor plan. Local code requirements vary: some jurisdictions require larger vent pipes, specific materials, or additional cleanouts, all of which add cost. And labor rates vary widely by region, so a rough-in that costs $6,000 in Ohio might cost $10,000 in California for the same house.
Rough-In for Additions and Remodels
Rough-in is not only for new construction. Adding a bathroom to an existing home requires rough-in work that typically costs $2,000 to $5,000 for the piping alone, plus demolition and finish work that can bring the total bathroom addition to $10,000 or more. The cost depends heavily on access: if the new bathroom is near existing plumbing, the tie-in is simple, but if it is on the far side of the house or on a slab, the plumber may need to cut concrete or run long pipe runs through finished walls. Remodel rough-in, such as moving a kitchen sink or relocating a toilet, costs $500 to $2,000 per fixture moved, and moving a toilet is the most expensive because the drain must be relocated. Before committing to a layout change, get a rough-in estimate from a licensed plumber, because the cost of moving plumbing often changes the design decision. Homeowners planning a full pipe replacement should also compare our repiping cost guide to understand whole-house pricing.
Budgeting Tips for Builders
Builders and owner-builders can control rough-in costs with a few smart decisions. Finalize the floor plan before rough-in starts: moving a fixture after the pipes are in costs $500 to $2,000 per change and delays the drywall schedule. Stack bathrooms and kitchens vertically and back-to-back so they share drain stacks and venting, which is the single biggest layout saving. Choose PEX over copper unless the project spec or local code requires copper. Buy fixtures early and have them on site before the finish phase so the plumber does not make extra trips. Get the rough-in bid in writing with the fixture count, pipe material, and inspection scope spelled out, and confirm whether the water service line, sewer connection, and gas piping are included or separate. Hold a contingency of 10 percent for rough-in, because hidden conditions such as rock, a high water table, or a failed inspection can add cost. Finally, schedule the inspection as soon as the rough-in is complete, because a failed inspection discovered after drywall is far more expensive to fix than one caught while the walls are still open.
Hiring a Rough-In Plumber
Rough-in is skilled work that sets the foundation for the entire plumbing system, so hire carefully. Verify the license and insurance, ask for references from recent new construction or addition jobs, and confirm the plumber has experience with your foundation type and pipe material. Get at least two or three written bids with the same fixture list so you can compare apples to apples. Ask whether the bid includes the pressure test, the inspection fees, and any re-inspection if the first inspection fails. Ask how change orders are priced, because a vague change-order policy is where budgets go to die. Confirm the schedule: rough-in must be coordinated with the framing crew and completed before insulation and drywall, so a plumber who cannot meet the schedule can delay the entire build. A reputable rough-in plumber warranties the workmanship for at least a year and stands behind the pressure test and inspection. For a free rough-in estimate on your new construction or addition project, call (877) 762-1902.