Seattle, WA
Seattle plumbing permit cost
Seattle does not issue plumbing permits.
Its own fee subtitle sends them to Public Health — Seattle & King County, whose schedule charges $137.00 for a plumbing or backflow permit plus $27.00 for each fixture — $245.00 for four fixtures — with plan review at $273.00 per hour, a $137.00 re-inspection and a $41.00 administrative fee. A gas piping permit uses the same base plus $27.00 per outlet.
How this fee is calculated
These are the components the schedule defines for this permit, as they applied on 2026-09-28. A component only applies to your project if its conditions match — read that column before assuming a figure. Want a figure for your own project? Estimate this fee with the permit fee calculator.
| Component | Formula | Applies when | Range |
|---|---|---|---|
| Already Built Construction permit, $273.00 plus $55.00 per fixturePermit fee | $273.00 plus $55.00 per fixture | permit kind is already built | — |
| Plumbing or backflow permit, $137.00 plus $27.00 per fixturePermit fee | $137.00 plus $27.00 per fixture | permit kind is not provided | — |
| Re-inspectionPermit fee | $137.00 flat fee | reinspection is true | — |
A real permit fee is these components added together. The department’s final calculation is the one that applies — this is the schedule it will be based on.
A worked example
Follow the arithmetic by hand. Every line is produced by the engine from the rules above, so the total cannot drift away from the schedule behind it.
Worked example
A bathroom remodel in Seattle replacing four plumbing fixtures, filed as one plumbing permit with the county health department.
| Input | Value |
|---|---|
| Fixtures | 4 |
Example total
$245.00
An estimate, not an official fee. It is calculated from the published fee schedule as it applied on 2026-09-28. The permit office’s own calculation is the one that applies, and your project may fall under rules this schedule does not describe.
Fee schedule as of 2026-09-28Rules applied 1Rules considered 3
| Component | How it is calculated | Amount |
|---|---|---|
Plumbing or backflow permit, $137.00 plus $27.00 per fixturePermit feePlumbing and Gas Piping Program fees: "Plumbing/Backflow Permit — $137 plus $27 per Fixture", effective January 1, 2026. The $137 is a base charge rather than a first fixture, which is why the allowance is zero and a one-fixture permit pays $164.00.Show the working
| $137.00 plus $27.00 per fixture | $245.00 |
| Total | $245.00 |
Fees that do not apply here
Listed so you can see what was considered and left out, rather than wondering whether something is missing. A rule can also be left out because it is not published for this permit at all, and that is stated where it matters.
- Already Built Construction permit, $273.00 plus $55.00 per fixture — This fee does not apply to the inputs provided.
- Re-inspection — This fee does not apply to the inputs provided.
Assumptions
- Calculated from 1 fee rule in effect on 2026-09-28.
- Amounts are rounded to the nearest cent, once, at the end of each component.
Four fixtures at $27.00 is $108.00, and the permit's $137.00 base is added to it rather than covering the first fixture: $245.00. A single-fixture permit is $164.00, not $137.00. Nothing Seattle charges is added, because the City does not issue this permit — the building permit, its plan review fee, the 5% technology fee and the state fee are separate charges from a different authority. A gas piping permit for the same job would be $137.00 plus $27.00 for each outlet.
What is different in Seattle
This is the only permit in this dataset whose authority is named by the jurisdiction that does not charge it. SMC 22.900G.030, inside Seattle's own fee subtitle, says: "Fees for plumbing, medical or dental gas, lab gas, and fuel gas piping shall be collected by the Director of King County Public Health in accordance with the fee schedule as set forth in Seattle Municipal Code Section 504." The City therefore publishes no plumbing fee of its own — and a reader who looks for one in the subtitle finds the instruction instead.
The schedule that instruction points to is short. A plumbing or backflow permit is $137.00 plus $27.00 per fixture. A gas piping or medical gas permit is the same $137.00 plus $27.00 per outlet. Plan review is $273.00 per hour, for either. A re-inspection is $137.00. An Already Built Construction permit, for work done without one, is $273.00 plus $55.00 per fixture or outlet, with fees already paid deducted from it. An inspection outside regular hours is $410.00 per hour, a requested site visit where no permit exists is $273.00, a permit renewal is $68.00 and an administrative fee for a modification, a correction or refund processing is $41.00.
The reading that matters most is the first one: the $137.00 is a base charge, not a first fixture. One fixture costs $164.00 rather than $137.00, because the row states the base without attaching an allowance to it. That single decision changes the price of every small permit, and it is the answer to the question people actually ask, which is what a water heater or a single fixture costs.
There is one more thing worth knowing, and it is why this page exists at all in a city whose own subtitle prices everything else. Because the plumbing authority is the county's, the same schedule prices plumbing permits in unincorporated King County, so Seattle and the unincorporated county share a plumbing fee while their building permits are priced by completely different governments — the City's index on one side, the county's two valuation tables on the other. A plumber working across the line pays the same plumbing permit either way and a very different building permit.
What this figure does not include
Impact fees, utility connections and other departments’ permits are the usual omissions, and in some jurisdictions they are larger than the permit fee itself.
Not included in these figures
This estimate is the Plumbing and Gas Piping Program's permit fee for the fixtures or outlets entered. It excludes:
- Plan review, which this program charges at $273.00 per hour rather than as a percentage of the permit, for both plumbing/backflow and gas piping.
- The $137.00 re-inspection, the $68.00 permit renewal, the $41.00 administrative fee, the $273.00 site visit where no permit exists, and $410.00 per hour for an inspection outside regular hours.
- The re-pipe supplemental fee, which the schedule calculates from the number of anticipated inspections times the program's hourly operating rate, using a worksheet it publishes.
- Gas piping priced per outlet, which is the same base with $27.00 per outlet rather than per fixture, and medical or lab gas, which is priced on the same rows.
- The Already Built Construction premium unless it is selected: $273.00 plus $55.00 per fixture or outlet, less any permit fees already paid.
- Everything Seattle itself charges for the same project — the building permit and its Development Fee Index, the plan review fee, the 5% technology fee and the state building code council fee — which are separate permits and separate authorities.
- Side sewer and drainage connection charges, which Seattle Public Utilities bills on its own accounts, and on-site septic work, which the same health department reviews under a different program.
- The cost of the fixtures and their installation, which is the work rather than the permit.
What you need before applying
- The plumbing permit is issued by the county health departmentRequired
SMC 22.900G.030: "Fees for plumbing, medical or dental gas, lab gas, and fuel gas piping shall be collected by the Director of King County Public Health in accordance with the fee schedule as set forth in Seattle Municipal Code Section 504." The schedule charges $137.00 plus $27.00 per fixture, and plan review at $273.00 per hour. Seattle does not publish a plumbing fee of its own.
Common questions
Who issues a plumbing permit in Seattle?
Public Health — Seattle & King County, not the City. Seattle's own fee subtitle says so at SMC 22.900G.030: "Fees for plumbing, medical or dental gas, lab gas, and fuel gas piping shall be collected by the Director of King County Public Health in accordance with the fee schedule as set forth in Seattle Municipal Code Section 504." The City publishes no plumbing fee of its own.
How much is a plumbing permit in Seattle?
$137.00 plus $27.00 per fixture, so four fixtures is $245.00 and one fixture is $164.00. The $137.00 is a base charge rather than a first fixture, which is why a single-fixture permit is not $137.00. Plan review is charged separately at $273.00 per hour.
How much is a water heater permit?
A replaced water heater is a fixture on the same schedule: $137.00 plus $27.00 for it, which is $164.00 if it is the only fixture on the permit. There is no separate flat water heater row in this program's schedule, so the per-fixture arithmetic is the published price rather than an estimate.
What is the difference between a fixture and an outlet?
Both are charged at $27.00, on different permits. A plumbing or backflow permit is $137.00 plus $27.00 per fixture; a gas piping or medical gas permit is $137.00 plus $27.00 per outlet. The base is the same, and the two are separate permits rather than two rows on one.
What if the work was done without a permit?
The Already Built Construction permit applies: $273.00 plus $55.00 per fixture or outlet for work "done without having paid any permit fees", with the schedule's own note that fees already paid are subtracted from the total. Four fixtures would be $493.00 before any such deduction.
Is this the same fee as in unincorporated King County?
Yes — the same schedule, because the same program prices both. A plumber working in Seattle and in unincorporated King County pays the same plumbing permit fee on either side of the line, while the building permit for the same job comes from the City's index in one case and the county's valuation tables in the other.
Source and verification
The documents behind every figure on this page, with the dates that make them checkable.
- Fee schedule (PDF)CountyPrimary source
Plumbing and Gas Piping Program service fees (effective January 1, 2026)
A county document that prices City permits, which is why it is recorded against Seattle as well as against King County. SMC 22.900G.030 is the City's own instruction: "Fees for plumbing, medical or dental gas, lab gas, and fuel gas piping shall be collected by the Director of King County Public Health in accordance with the fee schedule as set forth in Seattle Municipal Code Section 504." The figures are $137.00 plus $27.00 per fixture. The same PDF appears in the King County payload under the same key, because it is the same document and the same fee.
Verification
Last verified against the official source in Sep 2026.