Free Tool
Seattle Deck Permit Checker
Answer 5 questions to find out whether your deck project requires a City of Seattle building permit — based on current SDCI rules.
Answer all 5 questions above to see your result.
Do You Need a Permit for a Deck in Seattle?
Most deck projects in Seattle require a building permit through the Seattle Department of Construction and Inspections (SDCI). Whether you need one depends on several factors: the deck’s height above grade, whether it’s attached to the house, its square footage, location relative to Environmentally Critical Areas, and whether you’re adding electrical.
The main exception is a small, freestanding, low deck: under 18 inches above grade, under 200 square feet, detached from the house, outside any ECA, and with no electrical work. If all five conditions are met, Seattle’s residential code generally exempts the project from requiring a permit.
Permit costs for residential decks in Seattle typically run $300–$1,200 depending on project valuation. Seattle uses a valuation-based fee schedule, so larger or more complex projects pay higher fees. Budget $500–$800 for most mid-size decks.
How long does a Seattle deck permit take?Most standard residential deck permits through SDCI’s online portal currently take 4–8 weeks. Projects in Environmentally Critical Areas, or those with unusual complexity, can take considerably longer. Starting your permit application early — even before finalizing design details — is almost always worth it.
What’s included in a deck permit package?A typical Seattle deck permit submittal requires a site plan showing the deck’s footprint, setbacks, and relationship to the house; a framing plan with lumber species and sizing; footing and pier details; and at least one cross-section. Attached decks also require a waterproofing detail at the ledger connection. If electrical is involved, that’s a separate permit.
Working with a licensed GC like Timber & Rain means we prepare and submit all permit documents on your behalf. We’re familiar with current SDCI requirements and typically get a clean first submission — avoiding costly revision rounds that can add weeks to your timeline.