Plumbing permits in City of Seattle: fees, timeline & requirements (2026)
Everything you need to know about pulling a plumbing permit in City of 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 Seattle Department of Construction & Inspections (SDCI).
Free lookup, no account needed — your lot polygon, zoning, setbacks and overlays, cited to City of Seattle's source.
When does a plumbing need a permit in City of 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 City of Seattle adopted this rule
The threshold comes from the state code (WAC 51.56), which City of 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
plumbing
Who can do this work in City of Seattle?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, active through April 10, 2027, bonded and insured — working throughout City of Seattle and King County. Kolmo prepares the drawings and submittals, files the plumbing permit with Seattle Department of Construction & Inspections (SDCI), carries the project through review and inspections, and performs the construction. Call (206) 410-5100 for a City of 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. Confirm your parcel's zoning & overlays. Run an address lookup for your City of Seattle plumbing — we'll pull your specific lot polygon, zoning, setbacks, and any shoreline/ECA/historic overlays.
- 2. Assemble submittals (3).
- 3. Submit through the city portal: Seattle Department of Construction & Inspections (SDCI) ↗
- 4. Track review. Respond to reviewer comments promptly.
- 5. Pay issuance fees (Plumbing permit fees are set by fixture count in the city's fee schedule.) and pick up the permit. Inspection card travels with the job.
Or have Kolmo do it
We pull plumbing permits in City of Seattle every month. We prepare the drawings and submittals, file with Seattle Department of Construction & Inspections (SDCI), handle reviewer comments, and build the project.
Licensed WA general contractor KOLMOL*753JS · bonded & insured
Plumbing permits in City of Seattle — FAQ
When does a plumbing need a permit in City of 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 City of Seattle?
Current fee per the City of Seattle fee schedule: Plumbing permit fees are set by fixture count in the city's fee schedule.. Plus ancillary plan-review/tech-surcharge fees per city schedule.