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PermitRoadmap

Building permits in Unincorporated King County

Most construction, renovation, and repair work in Unincorporated King County, King County needs a building permit from Department of Local Services, Permitting Division. Below are the office's contact details and online portal, plus step-by-step guides for the projects homeowners ask about most, from roofing and solar to fences, sheds, pools, and HVAC.

Unincorporated King County is covered by the Washington State Building Code (RCW 19.27), which is in effect in every city and county and currently includes the 2021 International Residential Code as amended in chapter 51-51 WAC, the 2021 Uniform Plumbing Code (chapter 51-56 WAC), and the Washington State Energy Code (chapter 51-11R WAC). Building, plumbing, and mechanical permits are issued by the city, or by the county in unincorporated areas; a city or county without its own building department must contract with another jurisdiction or an approved inspection agency to enforce the code. Electrical permits and inspections come from the Department of Labor & Industries (L&I) unless the address is inside a city that runs its own electrical inspection program or inside Tacoma Power's service area. There is no statewide dollar-value permit exemption, although state law allows a city or county to adopt its own exemption for residential work valued at $1,500 or less. Confirm the requirements with the building department and the electrical inspection office that have jurisdiction over the address.

Permit guides for Unincorporated King County

Roof replacement or repairWindow or exterior door replacementSolar panel installationShed or accessory structureAddition or structural alterationInterior remodelingScreen enclosure or pool cageFence installation or replacementSwimming pool or spaPavers, driveway, or hardscapeHVAC replacement or installationElectrical panel or service upgradeStandby generator installationWater heater replacementPlumbing fixture or repiping

Permit FAQs for Unincorporated King County

Do I need a building permit in Unincorporated King County?
Most construction, renovation, and repair work in Unincorporated King County needs a permit, including structural changes, electrical, plumbing, mechanical, roofing, and pools. Small cosmetic work is sometimes exempt. Every project must still meet the 2021 International Residential Code as adopted and amended by the Washington State Building Code Council (chapter 51-51 WAC), even when a permit is not required. Check your exact project with the free PermitRoadmap check.
Who issues building permits in Unincorporated King County?
Department of Local Services, Permitting Division issues permits for property inside Unincorporated King County, King County. Your mailing city is not always the authority that permits your property, so confirm the jurisdiction before you apply. This page lists the department's phone, address, website, and online portal.
Can I pull my own permit as a homeowner in Unincorporated King County?
In Unincorporated King County, Washington law lets a property owner work on their own property without registering as a contractor (RCW 18.27.090), and do their own electrical work (RCW 19.28.261) and plumbing work (RCW 18.106.150), with exceptions such as electrical work on a new building intended for sale, rent, or lease, or on property offered for sale within 12 months of buying it. Owner-performed work still needs the same building, plumbing, mechanical, and electrical permits and inspections as work done by a contractor.
Is there a dollar amount under which no permit is needed in Unincorporated King County?
Not statewide. Washington sets no statewide dollar threshold that waives a building permit, so whether small or cosmetic work needs a permit is decided locally. Confirm the exempt-work list and any value threshold with Department of Local Services, Permitting Division before you start.
How much does a permit cost and how long does it take in Unincorporated King County?
Fees and review times are set locally and change often, so confirm the current numbers with Department of Local Services, Permitting Division or its online portal. Fees are usually based on the value of the work or a fixed schedule, and simple residential permits are frequently reviewed faster than new construction.

PermitRoadmap is an independent informational service and is not affiliated with any city, county, state agency, or permitting authority. Results are informational and do not replace confirming requirements with the local permitting authority.