How Much Does a Deck Cost in Seattle? 2026 Prices, Permits & Materials Guide

Updated October 2026 · Written by the Craft Boys crew — licensed Washington deck builders (Lic. #HOMERRA771N2) based in Redmond, with 300+ decks built and restored across Seattle and the Eastside.

"How much will my deck cost?" is the first question almost every homeowner asks us — and the honest answer is a range, not a single number. Below we break that range down: what decks actually cost in the Seattle area in 2026, why two decks of the same size can be priced $15,000 apart, how wood compares to composite in our wet climate, what each city requires for permits, and how to budget so there are no surprises.

Key takeaways

• A new deck in the Seattle area typically costs $45–$105 per square foot installed in 2026, depending mostly on the decking material.
• A common 16×20 ft (320 sq ft) deck lands around $14,000–$21,000 in pressure-treated wood, $18,000–$26,000 in cedar and $22,000–$34,000 in composite.
• Height, stairs, railing style, site access and demolition of an old deck move the price as much as the decking itself.
• Composite costs roughly 25–35% more upfront than cedar, but skips the re-sealing every 1–3 years that wood needs in the Pacific Northwest.
• Seattle requires a permit for most decks more than 18 inches above the ground; Eastside cities generally draw the line at 30 inches, attached decks or decks over 200 sq ft.
• Washington sales tax (about 10.35% in Seattle) applies to the whole project, labor included.

In this guide

1. How much does a deck cost in Seattle in 2026?
2. What drives the price of a deck
3. Wood vs. composite in the Pacific Northwest
4. Repair, restore or replace?
5. Covered decks, pergolas and patio covers
6. Railings and stairs: costs and code basics
7. Sealing and staining in a rainy climate
8. Do you need a permit?
9. How long does it take to build a deck?
10. Does a deck add value to your home?
11. How to choose a deck builder in Washington
12. Paying for your deck
13. Where we build
14. Deck cost FAQ

How much does a deck cost in Seattle in 2026?

In 2026 most professionally built decks in Seattle and on the Eastside cost $45 to $105 per square foot, all-in: footings, framing, decking, a standard railing, simple stairs and labor. Pressure-treated wood sits at the low end, cedar in the middle, composite near the top, and tropical hardwoods like Ipe above that. Seattle prices run higher than national averages because local labor, permitting and sales tax cost more.

For context, national cost guides put an average professionally built deck at about $30–$60 per square foot, while Angi's Seattle-specific data shows $44–$88 per square foot. The 2025 Cost vs Value report priced a 16×20 ft deck addition at $18,263 in wood and $25,096 in composite as a national average — Seattle projects usually come in above those figures.

Table 1. Typical installed cost per square foot in the Seattle area (2026)

These are market ranges for a deck at ground level to about one story high. Second-story decks, steep lots and custom shapes push toward the top of each range — or past it.

Deck cost by size

Multiply the area by the per-square-foot range and you get a realistic starting budget. Smaller decks usually cost more per square foot, because footings, stairs, permits and setup are fixed costs spread over fewer boards.

Table 2. Typical total cost by deck size and material (Seattle area, 2026, before sales tax)

Want to see what these budgets look like in real life? Browse our portfolio and recent projects, or read how we approach custom deck building from design to final inspection.

What drives the price of a deck?

Size and material set the baseline, but the structure underneath and the site around it often decide whether a deck lands at the bottom or the top of its range. These are the factors we price on every estimate.

Table 3. Cost factors and how much they move the price

One more line item people forget: in Washington, retail sales tax applies to construction labor as well as materials. In Seattle that is about 10.35% of the total, and most Eastside cities are close to it.

Wood vs. composite decking in the Pacific Northwest

In Seattle's climate — roughly nine wet months a year — composite usually wins on maintenance and lifespan, while cedar and pressure-treated wood win on upfront cost and natural feel. Composite costs about 25–35% more to install than cedar, but you skip the cleaning and re-sealing that wood needs every one to three years here.

Table 4. Decking materials compared for the Seattle climate

The 10-year math

Take a 320 sq ft deck. In cedar it costs roughly $17,600–$25,600 to build. Professional cleaning and sealing runs about $2–$4 per sq ft, so re-sealing every two years adds around $3,200–$6,400 over a decade. Composite costs about $22,400–$33,600 upfront and needs little more than a wash. Over ten years the two end up surprisingly close — and after that, composite keeps pulling ahead.

Whatever you choose, the framing underneath is usually pressure-treated lumber, and its condition is what really decides how long the deck lasts. That's why ground-contact-rated posts, proper ledger flashing and joist protection matter as much as the boards you pick.

Deck repair costs: repair, restore or replace?

If the framing — posts, beams, joists and ledger — is solid, repair or restoration almost always costs far less than a new deck. If rot has reached the structure, or the deck was built without flashing or with undersized lumber, replacement is safer and often cheaper long-term. Angi's Seattle data puts repairs on a 12×12 deck anywhere from about $630 to $9,500, depending on how deep the damage goes.

Table 5. What you see vs. what it usually takes

Warning signs worth a professional look: boards that feel spongy, posts sitting directly on soil, rusted hangers and fasteners, water stains on the siding below the ledger, and any railing that moves when you lean on it. Learn more about our deck repair and deck restoration services, or see a real example: a Redmond deck rebuild and expansion.

Covered decks, pergolas and patio covers

A cover is what turns a Seattle deck from a four-month space into a year-round one. An open pergola adds shade and structure; a pergola with a clear polycarbonate roof or a solid patio cover keeps the rain off while letting light through. Expect covers to add five figures to a project, with open pergolas costing far less.

Table 6. Typical cost of pergolas and covers (national cost guides)

See how we design pergolas and patio covers for rainy-climate living.

Railings and stairs: costs and code basics

Railings are priced per linear foot and the spread between materials is huge: a wood railing can cost a tenth of a glass one. Because a 16×20 deck can easily need 50–60 feet of railing, this one choice can swing the budget by $5,000–$20,000.

Table 7. Deck railing cost per linear foot, installed (national ranges)

Seattle-area labor typically pushes these national numbers toward the upper half. Whatever the material, the code basics don't change:

• Guards are required where the walking surface is more than 30 inches above the ground below, and must be at least 36 inches high.
• Openings in the railing must not let a 4-inch sphere pass through.
• Stairs: risers no taller than 7¾ inches, treads at least 10 inches deep.
• Handrails on stairs sit 34–38 inches above the stair nosing and must be graspable.

More on design options in our railings and stairs service page.

Sealing and staining in a rainy climate

Wood decks in the Pacific Northwest need cleaning and sealing every one to three years — horizontal boards that sit wet under firs and cedars need it on the shorter end. Professional sealing typically costs $0.75–$4 per square foot, and a full sand, stain and seal about $2–$4 per square foot. Composite needs no sealing at all.

Table 8. Deck care costs and frequency

The simple test: sprinkle water on the boards. If it beads, you're fine; if it soaks in within a minute, book the work for the next dry stretch. See our deck sealing and waterproofing service, including under-deck drainage for the space below.

Do you need a permit for a deck in Seattle or on the Eastside?

Usually, yes. In Seattle a permit is required for any deck more than 18 inches above the ground, any roof deck, and any deck in an environmentally critical area. Most Eastside cities follow the Washington residential code, which exempts only small, low, freestanding decks — 200 sq ft or less, no more than 30 inches above grade, not attached to the house and not serving the required exit door.

Table 9. Deck permit rules at a glance

Rules change and every lot is different, so treat this table as orientation, not legal advice. In Seattle, a deck that qualifies for a subject-to-field-inspection permit pays only 40% of the plan-review fee. Replacing a deck "like for like" still usually needs a permit if the new structure meets the thresholds above. On every Craft Boys project we check your address's requirements during the estimate and handle the drawings, submittal and inspections ourselves.

How long does it take to build a deck?

The build itself usually takes one to three weeks for a new deck; repairs take a few days and restorations two to five days. The calendar time before construction — design, HOA review and permits — is often longer than the build, which is why the best time to plan a summer deck in Seattle is winter.

Table 10. A typical deck project timeline

We build year-round: framing and composite installation are fine in the rain. Staining and sealing need dry days, so those are scheduled for drier stretches, typically late spring through early fall. Spring and summer book up fastest. Read more about how our process works.

Does a new deck add value to your home?

Yes — decks are consistently among the best-returning home projects. In the 2025 Cost vs Value report, a wood deck addition recouped about 95% of its cost at resale nationally, and a composite deck about 88%. In the Seattle market, where usable outdoor space is valued highly, a well-built, permitted deck is also a selling point buyers notice — and an unpermitted or rotting one is a red flag inspectors catch.

How to choose a deck builder in Washington

The cheapest bid is rarely the cheapest deck. Before you sign with anyone — including us — check these points:

1. Verify the registration on Washington L&I's Verify a Contractor tool. Registered contractors must carry a bond and liability insurance.
2. Get a written, itemized estimate — materials, labor, permits, demolition and disposal listed separately — not a number on a business card.
3. Ask who pulls the permit. If a contractor suggests skipping it, walk away: it's your house that carries the risk at resale.
4. Keep the down payment reasonable and tied to milestones, and ask for lien releases from suppliers as the job progresses.
5. Get the warranty in writing. Ours is a 10-year workmanship warranty on top of the manufacturers' product warranties — details on our warranty page.
6. Ask who actually builds it. An in-house crew means the people who quoted the job are accountable for it. Craft Boys uses no subcontractors.
7. Read the reviews and look at finished projects, not renderings. Here are our reviews and a Bellevue townhome deck rebuild.

For a printable version, grab our free contractor safety checklist at the end of this article.

Paying for your deck: financing options

You don't have to pay for a deck in one lump sum. Many homeowners finance through a home-equity line or a home-improvement loan. Craft Boys offers financing for qualified homeowners through GreenSky®; checking your options uses a soft credit inquiry that doesn't affect your score, and we go over terms during the estimate. See financing details.

Where we build: Seattle and the Eastside

Craft Boys is based in Redmond and builds, repairs and restores decks across King and Snohomish counties. Each area page covers what we build there and what to know locally:

• Deck builders in Bellevue
• Deck builders in Redmond
• Deck builders in Kirkland
• Deck builders in Sammamish
• Deck builders in Issaquah
• Deck builders on Mercer Island
• Deck builders in Medina
• Deck builders in Clyde Hill
• Deck builders in Bothell
• Deck builders in Mill Creek
• Deck builders in Laurelhurst
• Deck builders in Madison Park

Not sure if we cover your street? See all service areas or just ask us.

Deck cost FAQ