Deck Permit in Seattle, Washington
By Mario Bailey Last verified 2026-06-17 · 2 official sources
Quick answer
In Seattle decks more than 18 inches above the ground require a building permit from SDCI. Platforms and decks 18 inches or less above grade and not over a basement do not require a permit. Decks over 8 feet in height or over 750 square feet require a full addition/alteration permit rather than a simpler field-inspection permit.
Permit required?
Sometimes, depending on the project.
Typical threshold: decks more than 18 inches above grade require a permit; decks 18 inches or less above grade and not over a basement do not require a permit.
When a permit is usually needed
Before building any deck over 18 inches above grade or in an environmentally critical area in Seattle
Permit cost and what affects it
Fees are set by the locality and are not published here. See the official fee schedule or contact the office for current amounts.
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
Seattle Department of Construction and Inspections
- 700 5th Ave Suite 2000, Seattle, WA 98104
- Phone: (206) 684-8600
Frequently asked questions
- Do you need a deck permit in Seattle?
- In Seattle decks more than 18 inches above the ground require a building permit from SDCI. Platforms and decks 18 inches or less above grade and not over a basement do not require a permit. Decks over 8 feet in height or over 750 square feet require a full addition/alteration permit rather than a simpler field-inspection permit. The typical threshold is decks more than 18 inches above grade require a permit; decks 18 inches or less above grade and not over a basement do not require a permit. Always confirm with the office before starting.
- How much does a deck permit cost in Seattle?
- Fees are set by Seattle and are not published here. Contact the office for current amounts.
- How long does a deck permit take in Seattle?
- Processing time for a deck permit in Seattle varies by workload and project scope. Contact the Seattle Department of Construction and Inspections for a current estimate.
- Where do you apply for a deck permit in Seattle?
- You can apply through the Seattle permit portal or contact the Seattle Department of Construction and Inspections directly. The links are listed on this page.
Official sources
Last verified: 2026-06-17 Report an error on this page
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