Plumbing permits in Seattle: fees, timeline & requirements (2026)
Everything you need to know about pulling a plumbing permit in Seattle, Washington — when one is required, what it costs, how long review takes, what documents are required, and which inspections you can expect. Cited to Public Health – Seattle & King County.
Free lookup, no account needed — the office that issues the permit at your address, cited to Seattle's source.
When does plumbing work need a permit in Seattle?
SDCI does NOT issue plumbing permits in Seattle — the Seattle Plumbing Code is enforced by Public Health – Seattle & King County, and plumbing permits are applied for there. Side sewer is a third authority (SPU). WAC 51-56 requires a plumbing permit for installation, replacement, or relocation; like-for-like fixture/faucet replacement in the same location is generally exempt. Separately, SDCI requires no construction permit for minor repairs or alterations costing $6,000 or less in any 6-month period — but that exemption never covers load-bearing supports, building-envelope changes, or work reducing egress, light, ventilation or fire resistance, regardless of cost.
How Seattle adopted this rule
The threshold comes from the state code (WAC 51.56), which Seattle adopts by reference in the provision quoted below.
“The Seattle Plumbing Code consists of: (1) all of chapter 51-56 of the Washington Administrative Code (WAC) in effect on March 15, 2024, except Sections 51-56-008 and 51-56-0100; (2) amendments and additions to chapter 51-56 WAC adopted by the City Council by ordinance; and (3) Chapter 1, which is composed of all local provisions.”Source ↗verified 2026-07-27
Required submittals
- Fixture count + DFU calc
- Water heater specs
- Sewer line plan if site work
Inspection sequence
- Rough-in / pressure test
- Final
Contractor specialties needed
Plumber
Who can do this work in Seattle?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, active through April 10, 2027, bonded and insured — working throughout Seattle and King County. Kolmo manages the plumbing job from start to finish: a licensed plumbing contractor performs the work and the permit, and Kolmo coordinates the scope, schedule, inspections and any related construction. Call (206) 410-5100 for a Seattle plumbing quote.
Notes & caveats
Route plumbing permit questions to Public Health – Seattle & King County (kingcounty.gov → environmental health → plumbing & gas piping), NOT SDCI. Water heater: T&P relief, expansion tank if pressure >80psi. Sewer line: SPU side-sewer permit required for any work in ROW.
How to apply yourself
- 1. Check who issues the permit. Run an address lookup for your plumbing work in Seattle — we'll confirm which office issues the permit at that address.
- 2. Assemble submittals: the 3 documents under Required submittals above.
- 3. Apply with Public Health – Seattle & King County.
- 4. Track review. Respond to reviewer comments promptly.
- 5. Pay issuance fees (Public Health – Seattle & King County sets them) and pick up the permit. Inspection card travels with the job.
Or have Kolmo do it
Kolmo runs the job: a licensed plumbing contractor does the plumbing work and pulls the permit, and Kolmo coordinates the scope, schedule, inspections and any related construction.
Licensed WA general contractor KOLMOL*753JS · bonded & insured
Plumbing permits in Seattle — FAQ
When does plumbing work need a permit in Seattle?
SDCI does NOT issue plumbing permits in Seattle — the Seattle Plumbing Code is enforced by Public Health – Seattle & King County, and plumbing permits are applied for there. Side sewer is a third authority (SPU). WAC 51-56 requires a plumbing permit for installation, replacement, or relocation; like-for-like fixture/faucet replacement in the same location is generally exempt. Separately, SDCI requires no construction permit for minor repairs or alterations costing $6,000 or less in any 6-month period — but that exemption never covers load-bearing supports, building-envelope changes, or work reducing egress, light, ventilation or fire resistance, regardless of cost.
How much does a plumbing permit cost in Seattle?
Plumbing and gas piping permits in Seattle come from Public Health – Seattle & King County, not SDCI: apply and request inspections through Public Health (https://kingcounty.gov/en/dept/dph/health-safety/environmental-health/plumbing-gas-piping/applications-and-permits). Public Health's 2026 fee is $137 plus $27 per fixture ($137 plus $27 per outlet for a gas piping permit).