Estimate what your building permit will cost anywhere in Washington State. Enter your zip code and project type to get a fee range calibrated to your county.
Estimated Range
Permit Fee Breakdown
What affects your cost:
Important: These are estimates. The exact fee depends on your project's final scope and valuation. Contact the county building department for exact pricing.
Need help with your permit? Book a free call and we'll handle the whole process for you.
These are planning ranges, not a city invoice. We read each county's own published fee schedule directly wherever one exists. Where a county doesn't publish one, we estimate from comparable nearby counties instead of guessing, and every result clearly says which one you're looking at. The exact fee is always set by the issuing department.
✓Official county fee schedules used wherever one is published
✓Every result is clearly marked as "verified fee schedule" or "estimate only"
✓Final fees should always be confirmed with the issuing department
Does your project require a permit? Book a free call and let us handle it from drawings to approval.
How Permit Fees Are Calculated
Permit fees vary by city, but Washington jurisdictions generally rely on one or more of these methods:
Flat fee
A fixed amount based on project type. Common for smaller scope work like fences and water heater swaps.
Valuation-based formula
Most Washington jurisdictions charge a base fee plus a rate per $1,000 of project valuation, scaling in tiers.
Trade permits
Electrical, plumbing, and mechanical work are often permitted separately from the building permit, each with its own fee.
Plan review surcharge
Projects requiring plan review, like additions or structural changes, typically add 50-65% on top of the base permit fee.
Our estimates are based on published Washington State fee schedules. Actual fees may vary by jurisdiction. Check your city's adopted fee schedule for exact pricing.
Typical Permit Fee Ranges by Project
Calculated from real 2026 fee formulas in Washington State, applied at typical project valuations for each category.
Deck
$140 – $1,510
Fence
$105 – $785
Roof Replacement
$140 – $1,050
Adding Bathroom
$280 – $1,255
Interior Remodel
$370 – $1,650
Room Addition
$625 – $5,450+
DADU/ADU
$1,400 – $6,250+
Pool
$140 – $2,140
These are permit fees only and don't include construction costs, contractor fees, or inspection fees. Ranges are calculated from real published 2026 valuation-based fee formulas in Washington State, applied at typical project values for each category, then extended statewide using regional cost patterns.
Free Tool
Not Sure If You Need a Permit?
Before you estimate the cost, check whether your project needs a permit at all. Enter your zip code, pick your project, and get a clear yes, no, or maybe with a cited source, in under a minute.
How much does a building permit cost in Washington State?+
Most residential building permits in Washington cost between about $100 and $6,000, depending on the project and where you build. A fence typically runs $105 to $785, a deck $140 to $1,510, a bathroom addition $280 to $1,255, and a DADU or ADU $1,400 to $6,250 or more. Enter your zip code in the calculator above for an estimate calibrated to your county. The final fee is always set by the issuing building department.
How much does a building permit cost in Seattle?+
Seattle (SDCI) charges a base permit fee from its fee table, plus plan review equal to 100% of that fee and a 5% technology fee, which makes it one of the higher-cost places to permit in Washington. For example, a typical $8,000 deck comes to about $920, an $18,000 bathroom addition to about $1,250, and a $150,000 DADU to about $4,640 in building permit and plan review fees.
How much does a building permit cost in Snohomish County?+
In unincorporated Snohomish County, most residential permits are a $150 application fee plus a valuation-based permit fee, with plan review added at 65%. An $18,000 bathroom addition comes to about $875 and a $60,000 room addition to about $1,670, while decks, re-roofs and pools are a flat $140. Cities such as Everett, Lynnwood and Edmonds have their own building departments and fee schedules.
How much does a building permit cost in Bellevue or Sammamish?+
Bellevue and Sammamish are incorporated cities in King County, so each has its own building department and fee schedule, separate from Seattle and from unincorporated King County. Fees are generally based on project valuation with plan review added on top. Enter a Bellevue or Sammamish zip code in the calculator above for an itemized estimate based on the city's own fee schedule, and confirm the final amount with the city before you budget.
How are building permit fees calculated in Washington?+
Most Washington counties and cities base the fee on your project's valuation: a base fee plus a set rate for every $1,000 of project value, scaling in tiers. Plan review is usually added on top, typically 50% to 65% of the permit fee (100% in Seattle), and some jurisdictions add a small technology fee. Simpler projects like re-roofs, fences and pools are often charged a flat fee instead.
How much does a deck permit cost in Washington?+
A deck permit in Washington typically costs $140 to $1,510. Unincorporated Snohomish County charges a flat $140, while a typical deck in Seattle comes to about $920 once plan review is included. Small, low decks may not need a permit at all, while larger or taller decks usually need structural plan review.
How much does an ADU or DADU permit cost in Washington?+
Permit fees for an ADU or DADU in Washington typically run $1,400 to $6,250 or more. In Seattle, a typical $150,000 DADU comes to about $4,640 in building permit and plan review fees. Most jurisdictions treat a detached ADU like a small new home, so utility connection, site review or impact fees can add to the total.
Do I need a building permit for my project in Washington?+
Most structural, electrical, plumbing and mechanical work in Washington needs a permit, while some small repairs and low fences may be exempt. Use our free Do I Need a Permit tool to check your specific project against local code.
