Deck & Patio Permits: Kent vs Seattle
How do deck & patio permits rules compare between Kent, WA and Seattle, WA?
Kent and Seattle have similar restriction levels.
Kent, WA
King County
Decks not exceeding 200 square feet and not more than 30 inches above grade are generally exempt from permits in unincorporated King County. Larger or elevated decks require building permits. Concrete patios at grade do not require permits. Decks in flood zones or critical areas have additional requirements.
View full Kent rules →Seattle, WA
King County
Most decks in Seattle require a subject-to-field-inspection construction permit from SDCI. Patios and platforms under 18 inches above grade that are not over a basement do not need a permit. Decks over 36 inches above ground count toward lot coverage limits.
View full Seattle rules →Key Facts Comparison
| Fact | Kent | Seattle |
|---|---|---|
| Deck Exempt | ≤200 sq ft AND ≤30" above grade | - |
| Guard Rail | 36" min if >30" above grade | - |
| Patio at Grade | No permit needed | - |
| Critical Areas | Additional review required | - |
| Permit Required | - | Yes for most decks (STFI permit) |
| Exempt | - | Platforms under 18 inches above grade |
| Lot Coverage | - | Decks over 36 inches count toward limits |
| Railings | - | Required at 30 inches above grade |
Highlighted rows indicate differences between cities.
Kent FAQ
Do I need a permit for a deck in King County?
Not if the deck is 200 square feet or less, not more than 30 inches above grade, and does not serve a required exit. Larger or elevated decks require a building permit. Attached decks typically require permits regardless.
Can I build a deck near a stream in King County?
Development in critical area buffers (near streams, wetlands, slopes) requires additional review under KCC 21A.24. A critical areas alteration permit may be needed, and the deck may need to be set back from the buffer.
Seattle FAQ
Do I need a permit for a deck in Seattle?
Yes. Most decks require a subject-to-field-inspection construction permit from SDCI. Platforms under 18 inches above grade and not over a basement are exempt.
Does a deck count toward lot coverage in Seattle?
Decks more than 36 inches above the ground count toward lot coverage limits. In residential zones, total coverage cannot exceed 35% of the lot.
Compare other topics
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