Plumbing Permit in King County, Washington

Permit required?

Yes, a permit is required.

When a permit is usually needed

For all residential plumbing and gas piping installations or modifications in unincorporated King County

Permit cost and what affects it

Fees are set by the locality and are not published here. See the official fee schedule or contact the office for current amounts.

Permit costs generally depend on the project valuation, the scope of work, and the inspections required. Ask the office how the fee is calculated for your specific project.

Where to apply

• Official permit page
• Permit portal

Frequently asked questions

Do you need a plumbing permit in King County?

Residential plumbing and gas piping permits in unincorporated King County are issued by Public Health Seattle and King County not by the King County Permitting Division. A permit is required whenever you install, relocate, or change a plumbing or gas piping system. Homeowners may do their own plumbing but must obtain a permit. Inspections are required. Always confirm with the Public Health Seattle and King County before starting.

How much does a plumbing permit cost in King County?

Fees are set by King County and are not published here. Contact the office for current amounts.

How long does a plumbing permit take in King County?

Processing time for a plumbing permit in King County varies by workload and project scope. Contact the Public Health Seattle and King County for a current estimate.

Where do you apply for a plumbing permit in King County?

You can apply through the King County permit portal or contact the Public Health Seattle and King County directly. The links are listed on this page.

Official sources

• https://kingcounty.gov/en/dept/dph/health-safety/environmental-health/plumbing-gas-piping/applications-and-permits/
• https://kingcounty.gov/en/dept/local-services/certificates-permits-licenses/permits/permits-inspections-codes-buildings-land-use/do-you-need-a-permit