Do I Need a Permit to Build a Deck in Washington?

Deck permit requirements. When you need a permit, footing depth, guard rail rules, and inspection stages.

Yes — unless it's a small ground-level platform under 200 sq ft.

In Washington

WASHINGTON HAS ONE STATE BUILDING CODE IN FORCE EVERYWHERE, ADOPTED BY REFERENCE: "Except as otherwise provided in this chapter, there shall be in effect in all counties and cities the state building code which shall consist of the following model codes which are hereby adopted by reference:" IN ALL COUNTIES AND CITIES - the model codes named in that section are the code, without any act by your city. AND YOUR LOCAL GOVERNMENT MAY CHANGE IT, BUT ONLY IN ONE DIRECTION: "The governing bodies of counties and cities may amend the codes enumerated in RCW 19.27.031 as amended and adopted by the state building code council as they apply within their respective jurisdictions, but the amendments shall not result in a code that is less than the minimum performance standards and objectives contained in the state building code except as provided in subsection (2) of this section." NOT LESS THAN THE MINIMUM. So a local amendment may add to the state code and may not fall below it. That is the opposite arrangement from states that cap local rules at the model code, and it means a stricter local requirement in Washington is normal rather than suspect. FOR A HOUSE THERE IS A SECOND GATE, AND IT IS THE PART MOST READERS WOULD NEVER GUESS: "Except as provided in subsection (2) of this section, no amendment to a code enumerated in RCW 19.27.031 as amended and adopted by the state building code council that affects single-family or multifamily residential buildings shall be effective unless the amendment is approved by the building code council under RCW 19.27.074 (1)(b)." SHALL BE EFFECTIVE ONLY IF APPROVED BY THE BUILDING CODE COUNCIL. A local amendment touching single-family or multifamily residential buildings is not merely constrained - it does not take effect at all until a state council approves it. If you are told a local residential rule differs from the state code, that approval is the thing to ask about. BUT THE STATE CODE DOES NOT FIX THE NUMBERS YOU ACTUALLY DESIGN TO. The climatic and geographic design criteria - ground snow load, wind speed, seismic design category, frost line depth - are set by each city in its own code, and neighbouring Washington cities do not agree. STANWOOD AND AIRWAY HEIGHTS DISAGREE ON EVERY ONE OF THEM. Stanwood amends the International Residential Code table to a "Ground Snow Load 25 (roof snow load must also be 25psf unless proven otherwise by the structural engineer of record)", a "Wind Speed 110 mph", "Seismic Design Category D2" and a "Frost line depth 12"". Airway Heights publishes a "Ground Snow Load*: 39 lbs/ft2", a "Wind Speed (Gust): 85 mph", "Seismic Design Category: C" and a "Frost Line Depth: 24"" - with its own footnote that the "Minimum roof snow load to be 30 lbs/ft2 in the City of Airway Heights." READ THE LABELS, NOT ONLY THE NUMBERS. Airway Heights states its wind figure as a GUST; Stanwood's is unqualified. So the two cities do not even record the same measure, which is a further reason a figure cannot simply be carried across - you would be comparing one city's gust to another city's unlabelled speed. SO A FIGURE CARRIED FROM ONE WASHINGTON CITY TO THE NEXT WILL BE WRONG, and it can be wrong in either direction: Stanwood's ground snow load is LOWER than Airway Heights' while its stated wind speed is HIGHER. A plan drawn to one city's criteria is not a plan that passes in the other. AND ONE OF THOSE FIGURES IS NOT A FIXED NUMBER AT ALL. Stanwood's roof snow load is a default an engineer may displace - 25 psf "unless proven otherwise by the structural engineer of record". The way out is evidence, not discretion, and the code says so. ASK YOUR CITY FOR ITS DESIGN CRITERIA BEFORE YOU DRAW ANYTHING. They are published in the municipal code, not in the state code, and this guide cannot give them to you for your address. AND ON DECKS THE EXEMPTION IS NEVER JUST A HEIGHT. Shoreline exempts "Decks not more than 30 inches (762 mm) above grade at any point and detached from the dwelling and which are not part of an exit route." THREE CONDITIONS JOINED BY AND - a low deck that touches the house, or that carries the route out of a door, is not exempt however low it is. Spokane Valley's low-deck exemption likewise turns on all of its conditions being met rather than any one. AND WHERE A PERMIT IS REQUIRED, THE NUMBER YOU DESIGN TO CAN CHANGE WITHIN A SINGLE CITY: Bellevue's ground snow load is 25 psf below 500 feet, 30 psf from 500 to 600 feet, and 50 psf from 600 to 1,000 feet - so two decks in the same city, built to the same drawing, are not necessarily built to the same load. FIND YOUR SITE ELEVATION BEFORE YOU SIZE ANYTHING.

When a Permit Is Required

Most jurisdictions require a deck permit for: decks over 200 square feet, decks more than 30 inches above grade, any deck attached to the house via a ledger board, and decks with structural modifications. A small freestanding platform under 200 sq ft and under 30 inches high may be exempt — but check with your city.

Footings and Frost Line

Deck footings must extend below the local frost line — the required depth varies by climate and elevation, so confirm the depth your city requires. This is one of the most common inspection points. Footings that are too shallow will fail inspection.

Guards and Railings

Guards are required when the deck surface is 30 inches or more above grade. Minimum guard height is 36 inches for residential decks (42 inches for commercial) under the IRC. Baluster spacing must be less than 4 inches — the classic 'sphere test' (a 4-inch sphere should not pass through).

Ledger Board Attachment

The ledger board (where the deck attaches to the house) is the #1 failure point for decks. Inspectors check that ledger boards are attached with lag screws or through-bolts — nails are never acceptable. Proper flashing above the ledger is also required to prevent water damage.

Most useful decks need a permit. Plan for three inspections (footings, framing, final) and confirm your local frost-line footing depth.

Permit fees by city in Washington

Verified from each city’s published fee schedule. Where a city has no separate fee listed for this project, open the city page for the current requirements and amount.

25 rows

Permit fees by city in Washington
	Permit fee	Source
Bellevue	See city page for the current Deck Permit fee	Deck Permit →
Bonney Lake	Set by city council resolutionVerifiedvia Residential building permit	Residential building permit →
Clarkston	See city page for the current Deck Permit fee	Deck Permit →
Des Moines	Set by the City Manager or designeeVerifiedvia Residential building permit	Residential building permit →
Edmonds	Set by council resolution; not in codeVerifiedvia Residential Building Permit (New Construction)	Residential Building Permit (New Construction) →
Issaquah	$33.26 minimum, tiered by valuationVerifiedvia Residential Building Permit (New Construction)	Residential Building Permit (New Construction) →
Kenmore	Set by adopted fee scheduleVerifiedvia Residential building permit	Residential building permit →
Lake Stevens	Set by city council resolutionVerifiedvia Residential Building Permit (New Construction)	Residential Building Permit (New Construction) →
Longview	Set in the master fee scheduleVerifiedvia Residential Building Permit (New Construction)	Residential Building Permit (New Construction) →
Lynnwood	Set by city council fee ordinanceVerifiedvia Residential Building Permit (New Construction)	Residential Building Permit (New Construction) →
Maple Valley	Set by Development Fee ScheduleVerifiedvia Residential building permit	Residential building permit →
Mercer Island	Set by city council resolutionVerifiedvia Residential building permit	Residential building permit →
Moses Lake	Set by city council resolutionVerifiedvia Residential building permit	Residential building permit →
Mountlake Terrace	Set by annually adopted fee scheduleVerifiedvia Residential building permit	Residential building permit →
Pullman	Set by city council resolutionVerifiedvia Residential building permit	Residential building permit →
Puyallup	Set by city manager executive orderVerifiedvia Residential Building Permit (New Construction)	Residential Building Permit (New Construction) →
Sammamish	See city page for the current Residential Building Permit fee	Residential Building Permit →
SeaTac	Set by City of SeaTac Fee ScheduleVerifiedvia Residential building permit	Residential building permit →
Spokane	See city page for the current Deck Permit fee	Deck Permit →
Spokane Valley	See city page for the current Deck Permit fee	Deck Permit →
Tumwater	Set by city council resolutionVerifiedvia Residential building permit	Residential building permit →
University Place	Set by city council fee resolutionVerifiedvia Residential Building Permit (New Construction)	Residential Building Permit (New Construction) →
Vancouver	See city page for the current Deck Permit fee	Deck Permit →
Walla Walla	From $30.00, tiered by valuationVerifiedvia Residential building permit	Residential building permit →
Wenatchee	Not published in code; ask the cityVerifiedvia Residential Building Permit (New Construction)	Residential Building Permit (New Construction) →

See the national overview for this permit →