Plumbing and gas piping applications and permits

How to apply for a permit

For plumbing and gas piping installations, start by hiring a registered contractor.

Types of permits and fixtures

The Plumbing & Gas Program has updated its permit types and the types of fixtures that need to be listed on permits.

Permits:

•  Permit types and descriptions: Plumbing, fuel gas, backflow, and Medical Gas permit types and descriptions
• Plumbing permit decision tree (28 KB)
• Fuel gas permit decision tree (27 KB)
• Specialty permit decision tree (26 KB)

Fixtures:

• Fixture list with notes (MS Excel, 29 KB)
• Fixture list with notes (PDF, 230 KB)

Submit and manage your permit application

Use the Public Health Permit Center to:

• Apply for plumbing, backflow assemblies, gas piping, and medical gas permits
• Submit design documents for plan review
• Request an inspection
• Renew a permit
• Cancel a permit
• Check the status of your application or inspection

Resources:

• How to Use the Public Health Permit Center
• How to request changes to your plumbing permit (renewals, cancellations, extensions, contractor changes, and additional fixtures)
• Plumbing and Gas Program fees

Expired permits

To close out an expired plumbing or gas permit, you can either:

1. Obtain a new permit (standard approach). Pay the base permit fee. You will not be charged a per-fixture fee unless the original scope of work has changed.
2. Request a permit extension (limited availability, special circumstances). This option is reserved for very large projects with schedules exceeding the 3-year permitting period.  The party request must describe in writing any extenuating circumstances and why a permit extension is preferred over obtaining a new permit. Reviews for permit extension requests are expected to take 1-2 business days.

How to apply for plan review

A plumbing plan review must be completed by Public Health - Seattle & King County (Public Health) for certain occupancies.

1. Check if your project requires plan review: Occupancy and Use
• Some projects (schools, daycares, low-income housing) quality for priority review. Email planreviewinfo@kingcounty.gov to check if your project qualifies
2. View the information you are required to provide as part of your plan review: Plumbing Design Guidance
3. Submit your plan for review through the Public Health Permit Center

Resources to assist with plan review

• Schedule A: Links to water system disinfection requirements, plumbing system design guidance, re-pipe information, water reuse affidavits, and other helpful information
• Example Plan Registry
• Application for Alternate Material, Methods or Modifications (AMMRF)
• Medical gas categories and definitions

Questions about the plumbing plan review process: planreviewinfo@kingcounty.gov

How to get a homeowner's plumbing permit

Plumbing can be difficult. Public Health - Seattle & King County recommends you hire a professional plumber. If you choose to do your own plumbing, please adhere closely to the following instructions.

When a permit is required

Whenever you are going to install, relocate, or change a plumbing or gas piping system, Seattle and King County codes require that you obtain a permit. Public Health has jurisdiction in Seattle and unincorporated King County.

• Activities that require a permit: Description of activities that require or don’t require a plumbing permit, fuel gas permit, backflow permit, or Medical Gas permit
• Apply for a permit using the Public Health Permit Center 
• Find plumbing inspectors serving your area

The permit issued to a homeowner is an authorization for the homeowner to do the plumbing. (See RCW 18.106.150) If you are being authorized by the property owner to apply for the plumbing permit, your signature on the permit application signifies that you have such authorization from the owner of the property. If a professional plumber is contracted with, they must be a registered contractor, See RCW 18.106