Do I Need a Permit to Build a Deck in Seattle, WA?

Interactive check

Check your deck details

Client-side only. No runtime backend required.

Fees

Estimated city fees

Baseline for a simple permitted deck: $250–$700 estimated city fees for a permitted residential deck (varies by construction valuation; Washington State surcharge included)

Fee	Amount	Notes
Building permit fee	$250–$700 (estimated, based on construction valuation)	Seattle DCI calculates permit fees using a valuation-based sliding scale per the Seattle Construction Permit Fees schedule. Verify the current rate at seattle.gov/sdci/permits/permits-we-issue/building-permits before submitting.
Plan review fee	65% of the building permit fee (estimated)	Seattle DCI assesses a plan review fee equal to approximately 65% of the building permit fee for projects requiring plan check. Simple residential decks eligible for over-the-counter (OTC) review may have a streamlined plan review charge assessed at submission.
Washington State surcharge	Included in permit fee	Washington State Building Code Council assesses a small surcharge per permit, collected by Seattle DCI at the time of permit issuance and forwarded to the State Building Code Council.
Inspection fee	Included	Required inspections (footing/foundation, framing, final) are covered under the permit. Re-inspection fees apply if work fails or is not ready when the inspector arrives.

Documents

Required documents

Completed building permit application submitted through the Seattle Services Portal (seattleservicesportal.seattle.gov).
Site plan drawn to scale showing property lines, setbacks, critical areas, easements, existing structures, and the proposed deck location and dimensions.
Construction drawings including plan view, elevations, framing layout, footing sizes, and overall dimensions.
Structural details for footings, posts, beams, joists, connectors, guardrails, and stair configuration where applicable.
Ledger attachment detail and flashing specifications if the deck is attached to the dwelling.
Property survey or plot plan if the deck is near a setback line, easement, critical area, or utility corridor.
Critical area report or waiver if the property contains or is adjacent to steep slopes, landslide-prone areas, shorelines, or wetlands.
Owner authorization or contractor license documentation (Washington State contractor registration required) if a contractor applies on the owner's behalf.
Any required HOA approval documentation per your subdivision restrictions.

Timeline

Typical timing

Plan review: 10–20 business days (standard); over-the-counter same-day review available for eligible simple projects
Total cycle: 4–8 weeks from application to final inspection

Seattle DCI workload, critical area review requirements, resubmittals for plan corrections, and inspection scheduling can push the timeline toward the high end. Expedited review is available for an additional fee on eligible projects.

Process

How the permit process works

Determine whether your deck requires a permit Check whether the deck is attached to the house, or whether it exceeds 30 inches above grade at any point or 200 square feet as a freestanding structure. If any condition applies, a building permit is required through Seattle DCI. Also check whether your property is in or adjacent to a critical area, which may require additional review.
Prepare plans and supporting documents Draw up a site plan and construction drawings showing footings, posts, beam sizes, joist spacing, decking layout, guardrail details, and stair layout if applicable. Seattle plan reviewers reference the Washington State Building Code (WSBC), which is based on the 2021 IRC with Washington-specific amendments under WAC 51-51. Standard IRC-compliant structural details are generally accepted.
Submit through the Seattle Services Portal Create or log in to an account at seattleservicesportal.seattle.gov, select the appropriate residential building permit type, upload your documents, and pay the plan review deposit. Simple residential deck projects may qualify for over-the-counter (OTC) review, which can be completed the same day at the Seattle DCI permit counter at the Seattle Municipal Tower.
Respond to plan review comments Seattle DCI reviewers evaluate the submittal against the WSBC and Seattle Municipal Code Chapter 22.600. If corrections are requested, update the drawings and resubmit through the portal. OTC projects are reviewed while you wait at the DCI permit counter (700 5th Ave, Suite 2000, Seattle, WA 98104).
Receive approval and pay remaining fees Once the permit is approved and all fees are paid in full, download or print the issued permit. Keep the permit and approved plans accessible at the job site during all phases of construction. Seattle requires approved plans to be on-site during inspections.
Schedule required inspections Request inspections through the Seattle Services Portal or by calling the Seattle DCI inspection request line as construction progresses. A typical deck requires a footing or foundation inspection before pouring concrete, a framing inspection before covering structural members, and a final inspection.
Pass final inspection and close out the permit After the inspector signs off on the final inspection, the permit is closed and the completed deck becomes part of the official city record. This protects you during home sales, insurance claims, and future permitting in Seattle.

Code basis

What Austin reviews against

Washington State Building Code (WSBC) as adopted under WAC 51-51, based on the 2021 International Residential Code (IRC) with Washington-specific amendments. Enforced by the City of Seattle Department of Construction and Inspections (DCI) under Seattle Municipal Code Chapter 22.600 (Seattle Building Code).

Residential permit page AB+C portal

If you skip the permit

What can go wrong

Seattle DCI can issue a stop-work order if unpermitted construction is discovered.
The city may require the deck to be removed or structurally opened for inspection at the owner's expense.
Civil penalties and daily fines can accrue under the Seattle Municipal Code until the violation is resolved.
Homeowner's insurance may deny claims for damage caused by or related to unpermitted structures.
Unpermitted work flagged during a home sale can delay or derail a transaction, and retroactive permitting (an after-the-fact permit) is significantly more expensive and disruptive than doing it upfront.
Unpermitted decks may create liability exposure if a guest is injured on a structure not inspected for code compliance.
Washington requires a registered contractor for permitted work performed by a contractor; using an unregistered contractor can expose both owner and contractor to additional penalties under RCW 18.27.