Deck Permit in King County, Washington

Permit required?

Sometimes, depending on the project.

Typical threshold: uncovered decks 30 inches or less above ground do not require a building permit in unincorporated King County; decks over 30 inches above grade require a permit.

When a permit is usually needed

Before building an uncovered deck over 30 inches above ground in unincorporated King County

Permit cost and what affects it

Most permit fees increased approximately 14% on January 1 2026 plus a $126 application screening fee

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 deck permit in King County?

In unincorporated King County uncovered decks that are 30 inches or less above ground do not require a building permit. Decks more than 30 inches above grade require a building permit applied for through MyBuildingPermit.com. These rules apply to unincorporated King County only. If the deck is covered or attached in a way that affects structure contact the Permitting Division to confirm requirements. The typical threshold is uncovered decks 30 inches or less above ground do not require a building permit in unincorporated King County; decks over 30 inches above grade require a permit. Always confirm with the office before starting.

How much does a deck permit cost in King County?

Most permit fees increased approximately 14% on January 1 2026 plus a $126 application screening fee Contact the office for current amounts.

How long does a deck permit take in King County?

Processing time for a deck permit in King County varies by workload and project scope. Contact the King County Department of Local Services Permitting Division for a current estimate.

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

You can apply through the King County permit portal or contact the King County Department of Local Services Permitting Division directly. The links are listed on this page.

Official sources

• https://kingcounty.gov/en/dept/local-services/certificates-permits-licenses/permits/permits-inspections-codes-buildings-land-use/do-you-need-a-permit
• https://kingcounty.gov/en/dept/local-services/certificates-permits-licenses/permits