Seattle, Washington · Deck Building
Deck Builder in Seattle
A new deck around Seattle typically costs $40–$110 a square foot installed, and the material, the height and the slope of your yard decide where yours lands. Describe the project and our vetted local deck pro looks at the site and puts a price in writing.
Tell us about the deck and your town, and our vetted local deck pro gets back to you. No obligation.
Typical price in Seattle: Composite deck, installed$40–$75 per sq ft of deckSource: 5 Seattle-area contractor price pages, price data from September 17, 2026
How it works
1. Describe the deck
Choose the type of project, your town and how the company can reach you. The request takes a minute.
2. One vetted deck pro takes it on
Your details go to one vetted local pro and nobody else — no lead lists, no five sales calls. Until our vetted local deck pro is confirmed for your area, with its Washington contractor registration checked, the request is held and not shared with anyone. Once one is, that pro contacts you.
3. Site visit and written quote
The pro looks at the yard, height and access, then gives you a written quote. Whether you hire them is up to you.
Quick facts
- Composite deck, installed: $40–$75 per sq ft around Seattle. Cedar: $34–$45 per sq ft.
- Seattle permit needed for decks more than 18 inches above the ground, roof decks and decks in critical areas.
- Building a new deck typically takes 2–4 weeks once the permit is in hand.
- Cedar in Seattle's rain: restain every two to three years at $6–10 per sq ft.
- Tearing out an old deck adds $3–$8 per sq ft.
- Price ranges from sourced dataUpdated September 17, 2026
- 6towns covered in Seattle
- Registration checkedEach builder's Washington contractor registration is checked on L&I Verify before a request is passed onL&I Verify tool
Deck projects around Seattle
Composite decks
Low-upkeep boards on a wood frame, the pricier option up front. Prices, framing and railings: composite decks in Seattle.
Cedar and wood decks
Lower build cost, more finish work in a wet climate. See cedar and pressure-treated decks.
Repair and replacement
New boards on a sound frame, or a full tear-out and rebuild. Start with deck repair and replacement.
Railings, stairs and covers
Cable or glass rails, new stairs or a cover over an existing deck. Describe it in your quote request.
What does a deck cost in Seattle?
An installed composite deck costs $40–$75 per square foot around Seattle and a cedar deck $34–$45, based on the prices local contractors publish. Four things move the total most:
- Material. Composite costs more to build; cedar costs more to keep, with restaining every two to three years.
- Slope. Hillside requirements add $8–$20 per square foot over a flat-lot build.
- Railings. Cable rail runs $80–$150 per linear foot and glass panels $150–$300.
- Stairs and tear-out. A short 2–3 step run of stairs costs $1,200–$3,500, and removing an old deck adds $3–$8 per square foot.
The deck cost guide ranks each one with sources, how these ranges are compiled explains the method, and common Seattle deck questions covers build time and re-decking.
| Job | Price range | Source and date |
|---|---|---|
| Composite deck, installed | $40–$75 per sq ft of deck | Source: 5 Seattle-area contractor price pages, price data from September 17, 2026 |
| Cedar deck, installed | $34–$45 per sq ft of deck | Source: 3 Seattle-area contractor price pages, price data from September 17, 2026 |
| New deck, any material, installed | $40–$110 per sq ft of deck | Source: 4 Seattle-area contractor price pages, price data from September 17, 2026 |
| Removing an old deck | $3–$8 per sq ft of deck | Source: 3 Seattle-area contractor price pages, price data from September 17, 2026 |
Sources: 5 Seattle-area contractor price pages (listed in the cost guide) (September 17, 2026); 3 Seattle-area contractor price pages (listed in the cost guide) (September 17, 2026); 4 Seattle-area contractor price pages (listed in the cost guide) (September 17, 2026).
Prices are typical ranges, not quotes. Your price depends on the size, condition and access of the job.
Does your deck need a permit in Seattle?
Seattle requires a permit for a deck more than 18 inches above the ground, a roof deck, or a deck in an environmentally critical area such as a landslide-prone slope. Most decks go through the city's quicker subject-to-field-inspection permit. The suburbs set their own lines: Renton counts a 5 foot perimeter around the deck when it measures height, and Edmonds requires a permit even for repairs. Details are in the Seattle deck permit guide.
Composite or cedar for a Seattle deck?
Cedar costs less to build and more to keep: plan on restaining every two to three years at $6–10 per sq ft. Composite skips that work but typically runs $40–$75 per square foot installed around Seattle. Sun, shade and drainage on your lot tip the balance; the composite and wood deck guides go through both.
What does Seattle's rain mean for how a deck is built?
It means extra care where water collects, above all at the ledger: the board and flashing where the deck meets the house run $400–$1,200, and local builders treat that detail as non-negotiable in this climate. The city also requires treated or naturally decay-resistant wood wherever wood touches concrete close to the ground. Sun and drainage matter for the boards too: cedar only pays off on south-facing, well-drained flat lots, in neighborhoods like Beacon Hill, Columbia City and parts of West Seattle.
How do you know a deck builder is registered?
Look its registration number up on the state's L&I Verify tool before you sign; it shows the bond, insurance and any infractions. Washington law requires that number in all of a contractor's advertising, including internet ads, so it should be easy to find. The deck builder hiring checklist walks through it.
Planning a deck?
Send one request and we pass it to our vetted local deck pro in Seattle for a written quote.
Areas in and around Seattle
Requests are welcome from every Seattle neighborhood, including Ballard, West Seattle, Capitol Hill, Queen Anne, Northgate and Beacon Hill, and from these nearby cities, which each run their own permit counters.
Towns
Frequently asked questions
How much does a deck cost in Seattle?
About $40–$75 per square foot installed for composite and $34–$45 for cedar, going by the prices Seattle-area contractors publish. A 12 by 16 foot deck, a common Seattle backyard size, comes in near $10,500. The deck cost guide shows what moves the total.
Do you need a permit to build a deck in Seattle?
Yes, if the deck is more than 18 inches above the ground, is a roof deck, or sits in an environmentally critical area. Most decks qualify for the quicker subject-to-field-inspection permit, and each suburb sets its own threshold; see the Seattle deck permit guide.
How long does it take to build a deck?
Usually 2–4 weeks of building for a new deck. Permitting comes first: the city issues some simple permits within 48 hours, while decks that need full plan review take longer; more in Seattle deck questions.
Is composite or cedar the right choice for Seattle's rain?
Composite, if you want to skip the finish work: a cedar deck wants restaining every two to three years at $6–10 per sq ft. Cedar makes financial sense mainly on south-facing, well-drained flat lots. Compare composite decks with cedar and wood decks.
Should I repair or replace my deck?
Repair if the frame is sound, replace if it isn't. Re-decking a sound frame runs $55–$75 per square foot, against $70–$95 for a new composite deck; deck repair and replacement lists what to check first. Send a request and our vetted local deck pro will look at the job.
Who applies for the deck permit in Washington?
Usually the contractor you hire. In most instances a hired contractor is required to take out the permits, and the state treats a builder who asks you to get the permit as a warning sign; see the hiring checklist.
Reviewed by: Patrik Lorentzson, Editor, Seattle Quality Decks · Last reviewed
General information only, not advice for your project. Seattle Quality Decks does not advise on, design or manage projects; the contractor you choose does.