Do You Need a Permit to Repipe a House? PEX and Copper

Open wall during a whole-house repipe, with new red and blue PEX lines running through the studs next to old copper pipe

Pinhole leaks keep showing up in your copper, or the inspection report on the house you just bought flagged old galvanized or polybutylene supply lines.

A plumber quotes a whole-house repipe, and then comes the question nobody puts in the quote: do you need a permit to repipe a house? Some installers say yes right away. Others say it's "just replacing pipe" and skip it.

In every building department we checked, replacing the water piping inside a home is plumbing work that needs a permit and inspections, even when the new pipe follows the old routes. What changes from town to town is who can pull the permit, what paperwork you file, and what the inspector checks before the walls get closed. Below is how several real building departments handle it, in their own published words.

The short answer

Yes, a repipe usually needs a plumbing permit. Many cities' exempt-work lists cover stopping a leak, but once you cut out defective concealed pipe and replace it with new material, the work counts as new work. A whole-house repipe is well past that line. Expect a rough-in inspection with a pressure test before drywall goes back up, then a final inspection. If you're moving from metal pipe to PEX or CPVC, also plan for the electrical grounding and bonding question, because it can come up at inspection.

Fixing a leak vs. replacing the pipe

Copper water supply pipes with a ball shutoff valve in a home

Photo: Tony Webster, CC BY 2.0, via Wikimedia Commons

The exemption most homeowners have heard about is real, but it's narrow. Arlington, Texas lists "the stopping of leaks in drains, water, soil, waste or vent pipe" as work that doesn't need a permit. The same line goes on to say that if a concealed pipe "becomes defective and it becomes necessary to remove and replace the same with new material, such work shall be considered as new work, and a permit shall be obtained and inspection made." Repairing leaks in pipes, valves, or fixtures is also exempt only when it doesn't involve replacing or rearranging valves, pipes, or fixtures. (City of Arlington: Work Exempt From Permitting)

Milpitas, California puts it even more plainly: "The installation or replacement of a water piping within a building requires a plumbing permit." Faucets and valves can be replaced in the same location under that same water piping permit. But if the job involves extensive removal of walls or ceilings, Milpitas requires a building permit too. (City of Milpitas: Water Piping (Residential)) If a burst pipe forced you to act fast, our guide to emergency repair permits covers how cities handle work that has to start before the paperwork does.

How a repipe permit works in six places

King County, Washington: an over-the-counter permit for houses

Public Health - Seattle & King County defines a re-pipe as any project whose main scope is replacing all or part of a building's water supply or drainage piping, with the same material or a different one. Re-pipes covering three or more stories go through plan review, but single-family homes, duplexes, triplexes, and townhouses are excepted. For those, the plumbing contractor, or the homeowner if they're doing the work themselves, pulls an over-the-counter permit through the online portal. The permit lists "re-pipe" fixtures (hot water, cold water, drainage) plus any fixture being replaced that needs in-wall changes, such as a tub and shower valve. (PHSKC: Plumbing Permit Application Process for Re-Pipe Projects)

Margate, Florida: contract, plans, and a notarized form

Margate has a dedicated water repipe checklist. The minimum package is a notarized Broward County Uniform Building Permit Application, documented proof of cost covering labor and materials for all trades (a signed contract), and a set of plans. The city says it won't accept the application without them. (City of Margate: Water Repipe Permit Application Checklist) The Broward application in that packet also warns owners that a notice of commencement must be recorded and posted on the job site before the first inspection.

Austin, Texas: homeowners can do it, with conditions

Texas law says a property owner doesn't need a plumbing license "to perform plumbing in the property owner's homestead." (Texas State Board of Plumbing Examiners: Plumbing License Law, Sec. 1301.051) That isn't a pass on permits. Austin requires a Homestead Permit: you need a homestead exemption on file with the county appraisal district, the house has to be your principal residence, the work has to be done by the person who got the permit, and you can't have had a homestead permit for another residence in the prior 12 months. Austin also excludes some systems from homeowner work, including the main electric service and liquefied petroleum plumbing systems. (City of Austin: Homeowner's Permit)

Saint Paul, Minnesota: the water utility may be your permit office

Saint Paul splits plumbing permits between two offices. Its plan review guidelines say that when the scope of work is only the water service, the meter, or the water distribution piping, plans, permits, and fees go to Saint Paul Regional Water Services, not the city's Department of Safety and Inspections (DSI). DSI handles waste, vent, and gas piping. So a supply-only repipe there starts with the water utility. For DSI plumbing permits, an owner-occupant of a single-family home has to apply in person, read and sign the Home Owner's Plumbing Affidavit, show identification, and pay the inspection fee. (City of Saint Paul: Plumbing Plan Review Guidelines)

San Dimas, California: a checklist built for PEX and copper

San Dimas publishes a repipe checklist that reads like an inspector's notes. Pipe running through framing within 1 inch of the exposed edge needs steel nail plates of at least 18 gauge, hose bibs need non-removable backflow preventers, and a metallic gas piping system has to be bonded to the main electrical panel when a PEX repipe goes in. If part of the water line runs in the public right-of-way, a separate encroachment permit from public works may be required. (City of San Dimas: Water Supply Line Repipe & PEX/Copper Repipe Checklist)

Milpitas, California: owner work has a backstop

Milpitas issues building permits only to the owner or an authorized agent. If an owner does the work and an inspection shows it can't be completed satisfactorily, a licensed contractor has to finish it. If the owner hires workers, state law requires workers' compensation insurance, with proof required before inspection. (City of Milpitas)

For more on who should be named on the permit, see owner-builder permits. Our broader plumbing and gas line permit guide covers other plumbing jobs, like moving a sink or adding a fixture.

Inspections: keep the walls open until the rough-in passes

New water supply pipe visible through a section of drywall cut open during a repipe

Photo: heymarchetti, CC BY-SA 2.0, via Flickr

In a finished house, new lines often run through openings cut in drywall and ceilings. That's where the timing matters. Milpitas says two inspections are typical: a rough plumbing inspection after the new piping is in but before wall or ceiling coverings go on, and a final after all work is done. The pressure test usually happens at the rough inspection. Under Milpitas' handout, a water test has to be at least the system's working pressure, an air test has to be at least 50 psi, plastic pipe can't be tested with air, and the system has to hold for at least 15 minutes without leaking. (City of Milpitas)

Cover the pipe too early and you'll be opening it back up. San Antonio's plumbing bulletin says permitted plumbing work has to stay accessible and exposed until the code official approves it, and "if any such work is covered, it shall be uncovered." The same bulletin says a failed inspection is automatically assessed a reinspection fee, listed at $57.50. (City of San Antonio: Information Bulletin 182)

Two more things can catch you at the final. In Milpitas, required smoke and carbon monoxide alarms and water-conserving fixtures have to be in place and verified as a condition of final approval. (City of Milpitas) Our guide to smoke and CO alarm rules when you pull a permit explains why a plumbing job can trigger an alarm check. And for the patching afterward, see how much drywall you can replace without a permit. For a walk-through of rough-in and final visits, read building permit inspection prep. If you plan to add a whole-house softener while the lines are open, read do you need a permit to install a water softener.

Switching from metal pipe to PEX or CPVC: the grounding question

Copper grounding wire clamped to a metal water pipe near the water main

Photo: z22, CC BY-SA 3.0, via Wikimedia Commons

In some homes, the metal water pipe is part of the electrical grounding system. Pull it out and replace it with plastic, and that path can disappear. Milpitas' handout says that where metal water piping is used for grounding, replacement piping has to be a like material, unless a grounding system acceptable to the building official is installed, inspected, and approved. Then the metal pipe can be replaced with nonmetallic pipe. (City of Milpitas)

San Dimas goes further on its checklist. Replacing a metallic water service with plastic may require a new grounding electrode system, a label stating "This structure has a nonmetallic water distribution line" has to be fastened to the main electrical meter panel where plastic piping is used for the building supply, and the gas pipe bonding mentioned above applies to PEX repipes. (City of San Dimas) This is a common surprise. One r/HomeImprovement thread is titled "PEX repipe job is complete. Planned to get it permitted, but plumber says electrical may be flagged." Ask your plumber who will handle the grounding before the first pipe is cut. If an electrician is needed, our whole-home rewire guide explains how electrical permits run alongside other trades.

Repipe permit checklist

Call your building department and ask: does a repipe need a plumbing permit, a building permit for wall openings, or both?
Ask who may pull it. Some places let an owner-occupant do it (King County, Saint Paul through DSI, Austin with a Homestead Permit). Elsewhere you may need a licensed plumber.
Confirm the pipe material is approved locally. Milpitas, for example, requires potable water pipe and fittings to comply with NSF/ANSI/CAN 61 and the materials table in the California Plumbing Code (City of Milpitas).
Get the paperwork together: signed contract, scope, and plans if your city asks for them, as Margate does.
Settle grounding and bonding before work starts if you're replacing metal pipe with plastic.
Leave every opening uncovered until the rough-in inspection and pressure test pass.
Before the final, check smoke and CO alarms and any fixture rules your city attaches to plumbing permits.

FAQ

Do I need a permit to replace copper pipe with PEX?

Usually yes. Milpitas requires a plumbing permit for installing or replacing water piping inside a building, and King County's re-pipe definition covers new piping of the same or a different material. A material change can also bring up grounding, as covered above.

Do I need a permit to fix a pinhole leak?

Often not, if you're only stopping the leak. Arlington exempts stopping leaks, but treats removing and replacing defective concealed pipe with new material as new work that needs a permit. Check your own city's exempt-work list.

My contractor says a permit isn't necessary. Who's right?

Ask the building department directly, in writing if you can. As the owner, you're the one who lives with unpermitted work. That can include having to open walls later so an inspector can see the pipe, as San Antonio's rule on covered work shows.

The repipe is already done without a permit. What now?

Many cities let you apply after the fact, though you may have to expose pipe for inspection. Our guide to after-the-fact permits walks through the process.

Local rules change, and every city above can update its handouts. Confirm with your own building department before you start.

If the job is only replacing a toilet, faucet, or sink rather than the supply pipes, see our guide to permits for replacing plumbing fixtures.

Last checked: October 31, 2026.

Official sources

Edited by Ahmed Khalifa, founder of PermitCove. Sources are linked inline; see our Editorial Policy.

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