Deck permit requirements across 16 Seattle-area cities
Side-by-side: which of Seattle, Bellevue, Kirkland, Redmond, Sammamish, Issaquah, Renton, Kent, Federal Way, Mercer Island, Shoreline, Tacoma, Lakewood, Puyallup, Everett, Lynnwood require a permit for a deck, and what triggers one — each row quoted from the city's own code or permit page, with the source linked. Fees and review times appear where the city publishes them.
14 of 16 cities have authoritative rules on file · 1 always require a permit · 15 depend on the scope · 0 do not.
King County
| Jurisdiction | Permit? | Threshold | Fee | Review days | Source |
|---|---|---|---|---|---|
city | Depends on scope | A deck 30 in or less above grade needs no permit, attached or not, unless it is over a story below or part of an accessible route or an exit path. Bellevue's permit FAQ (Work Requiring Permits, Decks): no permit is required for installing or repairing a deck that is less than 30 inches above the ground. A permit with plan review is required for installing, repairing, replacing and adding to decks where the highest walking surface is more than 30 inches above the ground. A permit is required for repairs to existing deck or porch handrails and stairs. Bellevue LUC sets setbacks by zone. | — | 7–14 days | Cite verified 2026-08-04 |
city | Depends on scope | A detached deck up to 200 sq ft and 30 in above grade that does not serve the exit door needs no permit outside a critical area. A larger, higher or attached deck, one serving the exit door, or any deck in a critical area or flood hazard area, needs one. A building permit is required for a deck larger than 200 sq ft, OR greater than 30 inches above the ground, OR attached to the house, OR within an environmentally critical area or buffer. Decks ≤200 sq ft and ≤30 inches above grade are exempt. | — | — | Cite verified 2026-05-29 |
city | Depends on scope | A deck no more than 30 in above grade needs no permit, attached or not, and replacing decking boards alone needs none; in a flood hazard or critical area every deck needs a permit. A permit is required before any repairs, additions, or modifications to a deck more than 30 inches above grade (measured to the lowest point within 6 feet of the deck). Setbacks per IMC 18.404 by zone; decks in mapped ECA areas trigger critical-area review. | — | 14–28 days | Cite verified 2026-05-29 |
city | Depends on scope | Exempt only when all hold: 200 sq ft or under, 30 in or under at any point, not attached, and not serving a required exit door. A deck is exempt only if ≤200 sq ft, ≤30 inches above grade at any point, not attached to a dwelling, and does not serve a required exit door (IRC R311.2); otherwise a building permit is required. | — | — | Cite verified 2026-05-29 |
city | Depends on scope | A deck at a house 30 in or under above grade and not over a basement or story below needs no permit, attached or not, and neither does replacing decking boards alone, except in a flood hazard area, a critical area or its buffer, or a wildland-urban interface (WUI) location. The City's "Deck Installation or Repair" page, citing KMC 21.06.215: a building permit is NOT required for a deck that is (a) not more than 30 inches above grade, AND (b) not over any basement or story below, AND (c) not part of an accessible route. All three must hold — a 24-inch deck over a basement, or one forming an accessible route to an entrance, still requires a permit. The code's own list, KMC 21.06.215(1)(F), exempts decks "constructed under the provisions of the IRC, which are not more than thirty inches above grade and not over any basement or story below"; the accessible-route condition is the City page's. Decking-board replacement that does not change/add structural members or remove guardrails is separately exempt: KMC 21.06.215(1)(U), "Decking replacement on decks without changing or adding any other structural members or removing guardrails." The guard is not covered by this exemption: Kirkland Development Services confirmed at the counter on 2026-08-06 that a deck may be exempt while its railing still requires a permit, so the deck and the guard are evaluated separately. None of this is exempt in a flood hazard area, a critical area or its buffer, or where the International Wildland-Urban Interface Code applies. KMC 21.06.215: "Permit exemptions shall not apply to areas of flood hazard or city land use critical areas and their required buffers, or locations subject to the construction requirements of the International Wildland-Urban Interface Code." | — | — | Cite verified 2026-08-05 |
city | Depends on scope | A deck 30 in or less above grade and not over a story below needs no permit, attached or not, and neither does replacing decking boards alone. A higher deck, one over a story below, or any deck work in a critical area, a flood hazard area or a wildland-urban interface (WUI) location needs one. Permit NOT required for sidewalks, decks and driveways constructed under IRC, not more than 30in above grade and not over any basement or story below. Decking replacement on existing decks WITHOUT changing/adding structural members and WITHOUT removing guardrails is also exempt. Per the multi-jurisdiction tip sheet, the 30-inch measurement is taken vertically to the grade below at any point within 36 inches of the outer edge of the deck. Critical-area / flood-hazard exemption rule applies. | — | — | Cite verified 2026-04-29 |
city | Depends on scope | A detached deck up to 200 sq ft and 30 in or less above grade that does not serve the required exit door needs no permit; an attached, larger or higher deck does. A permit is required for a deck that is attached to a structure, over 200 sq ft, or more than 30 inches above grade. A detached deck not over 200 sq ft and under 30 inches in height is exempt. | — | — | Cite verified 2026-05-29 |
city | Depends on scope | A deck 30 in or less above grade needs no permit, attached or not, unless it is over a story below, part of an accessible route, or in a wildland-urban interface area, a flood hazard area or a critical area. A deck is exempt only if 30 inches or less above grade, not over a basement/story below, and not part of an accessible route (RMC 4-5-060 §105.2). Above 30 inches a building permit is required; guards are required at walking surfaces over 30 inches. | — | — | Cite verified 2026-05-29 |
city | Depends on scope | A deck 30 in or less above grade needs no permit, attached or not and at any size, unless it is over a story below, part of an accessible path, in a critical area or within the standard shoreline setback. Replacing only the decking boards needs no permit. Plans are required for new or enlarged decks. A deck is exempt only if it is ≤200 sq ft, ≤30 inches above grade at any point, not attached to a dwelling, and does not serve a required exit door (adopted 2021 WA IRC R105.2(10)). Deck repair that does not expand or change the footprint needs no site plan. | — | — | Cite verified 2026-05-29 |
city | Depends on scope | A deck 18 in or less above grade, not over a basement or story below, outside a flood hazard area and not on an environmentally critical area parcel needs no permit, at any size and attached or not. Otherwise it needs a permit or approval. Permit required if: deck >18in above grade, OR roof deck, OR in an ECA. Decks ≤18in above grade and outside ECAs are exempt. If deck >36in above grade, it counts toward lot coverage. If deck >8ft tall, has long beams, is a roof deck, or in an ECA → Construction Permit (Addition/Alteration); otherwise Subject-to-Field-Inspection. | — | — | Cite verified 2026-04-26 |
city | Depends on scope | A detached deck no more than 30 in above grade at any point, and not part of an exit route, needs no permit; an attached deck or anything higher does. A construction permit is not needed for decks 30 inches or less above grade and not over a basement; above 30 inches a building permit is required. Footing inspections must be made after forms are set and steel placed but before pouring concrete. | — | — | Cite verified 2026-05-17 |
Pierce County
| Jurisdiction | Permit? | Threshold | Fee | Review days | Source |
|---|---|---|---|---|---|
city | Always | Lakewood's building code gives no permit exemption for decks, so building a deck needs a building permit. Permit NOT required if ALL of: not attached + <30in above grade at any point + <200sqft + does not serve as main entry door + (for shoreline properties) not more than 18in high. Critical-area proximity always triggers permit. | — | — | Cite verified 2026-04-29 |
city | Depends on scope | A deck 30 in or less above grade that is not over a basement or story below needs no permit in Puyallup, attached or not. A higher deck, one over a story below, or a covered deck needs one. Permit required for uncovered decks >30in above grade OR decks serving the exit door required by IRC Section R311.4. Covered porches and patios also require permit (counted as additions). | — | — | Cite verified 2026-04-29 |
city | Depends on scope | A free-standing deck 30 in or under is exempt. Higher, or attached, needs a permit. Tacoma TMC 13.05: permit if deck >30in above grade or attached. Apply via Accela ACA. | Tacoma counts an attached deck as an addition: the combination permit is 2.81% of valuation (uncovered wood decks valued at 67% of ICC Building Valuation Data, Table 8-5), plan review 45% of that fee, and the site development permit at 65% plus 45% for its review, which Table 8-4 Note 1 lets the city adjust where all hard surfaces total under 2,000 sq ft. Table 1 adds the Technology Program (5%), Natural Resources Program (5%) and Reserve Fund (2%) on permit and plan review fees and Emergency Preparedness (5%) on permit fees; the state building code fee is $6.50. | 10–21 days | Cite verified 2026-04-29 |
Snohomish County
| Jurisdiction | Permit? | Threshold | Fee | Review days | Source |
|---|---|---|---|---|---|
city | Depends on scope | A free-standing deck 30 in or less above grade is exempt under the state code. Attached decks and anything higher need a permit. Everett follows IRC default: permit required if deck >30in above grade or attached. Critical-area overlays may require additional review. | — | 10–21 days | Cite verified 2026-04-26 |
city | Depends on scope | Under the state code a deck needs no permit only when it is 200 sq ft or less, no more than 30 in above grade at any point, not attached to the house, and does not serve the required exit door. Many cities change this in their own codes. 2021 IRC R105.2 (Building, item 10), adopted in Washington without amendment by WAC 51-51-003, exempts a deck only when it does not exceed 200 sq ft, is not more than 30 in above grade at any point, is not attached to a dwelling, and does not serve the exit door required by R311.4. Many cities set their own rule (Seattle: 18 in). | — | — | Cite verified 2026-10-02 |
How this table is built
Each row reflects the most-recently-verified authoritative rule on file for that jurisdiction and project type. “Pending verification” means we have the jurisdiction in our database but haven't yet personally checked the city page for deck rules — those rows fall back to county or WA-state baselines until verified. Sources link directly to the city or county page we read on the verified-on date. See our data-quality leaderboard for how we keep these current.