Building Permits in Washington

We cover 37 cities in Washington. Select a city below to see local permit requirements.

37 Cities Covered

3,848 Permit Rules

IRC Building Code Base

Building Codes in Washington

Building permit requirements in Washington are enforced at the local level, each city and county building department sets its own rules, fees, and timelines. Most cities in Washington follow the 2021 IRC.

We cover 37 cities in Washington with 3,848 specific permit rules. That's real, locally researched data, not generic advice. Each city page shows exactly what triggers a permit, what's exempt, estimated fees, and how to apply.

The bottom line: don't assume your city follows the same rules as the one next door. A fence that's exempt in one town might need a full permit two miles away. Always check your specific city.

Permit Fees Across Washington

Across the 37 cities we cover in Washington, permit fees range from $25 – $7,500. The average sits around $183 – $759.

Fees vary a lot by city and project type. A simple fence permit might run you $50, while a full room addition could be $2,000+. Most cities calculate fees based on your estimated project value, typically 1–2% of construction cost. Check the specific city page for accurate numbers.

Common Permit Exemptions in Washington

These are the most common projects that don't require a permit across cities in Washington. Keep in mind, "exempt from a permit" doesn't mean "exempt from code." You still have to build to code even without a permit.

Fence: Exempt in 66 of our 37 covered cities

Windows and Doors: Exempt in 64 of our 37 covered cities

Tree Removal: Exempt in 37 of our 37 covered cities

Siding: Exempt in 37 of our 37 covered cities

Shed: Exempt in 37 of our 37 covered cities

Exemptions vary by city. Always verify with your local building department before starting work.

Contractor Licensing in Washington

If you're hiring a contractor in Washington, make sure they're properly licensed. You can verify credentials through the Washington L&I – Contractor Registration.

Two rules of thumb: never pay a contractor in full upfront, a third down is standard. And if a contractor tells you "we don't need a permit for this," that's a red flag. Use PermitMint to verify before you sign anything.