How much does it cost to build a deck in Seattle, WA?
A new deck in Seattle, WA typically costs $30–$65 per square foot installed — a 16×20 pressure-treated deck runs roughly $10,000–$18,000, and composite decking pushes the same deck to $16,000–$28,000. Honest quotes include permits, footings, stairs, and railings; they're the most common 'extras' in cheap ones. Height matters: a raised deck costs meaningfully more than a ground-level one.
What you can check yourself
- Decide material first: pressure-treated lumber is cheapest; composite costs ~60% more upfront but skips sealing and most maintenance.
- Ask whether the quote includes the permit and inspections — most towns require both for raised decks, some for all decks.
- Get the footing depth and ledger-attachment method named in writing; ledger failure is how decks collapse.
Typical cost
Typical in Seattle, WA: $30–$45/sq ft pressure-treated; $50–$65/sq ft composite. Stairs, benches, and lighting add $500–$3,000.
When to call a pro
Decks attach to the house and carry crowds — permit-and-inspection work for a licensed contractor, not a weekend crew. An existing deck with a pulling-away ledger board or rotted posts shouldn't host a party until it's inspected.
General Contractor pros in Seattle, WA
- ALTA CONSTRUCTION INCORPORATED · 300 PINE ST, SEATTLE, WA · 9512792762
- A2 BUILDS LLC · 526 1ST AVE S # 213, SEATTLE, WA · 2069208215
- 1029 SOUTH JACKSON STREET APTS INVESTORS LLC · 1029 S JACKSON ST, SEATTLE, WA · 2067286543
- ACMS NORTHWEST · 450 ALASKAN WAY S # 223, SEATTLE, WA · 5034905673
- 3 4 5 BUILDERS LLC · 516 29TH AVE, SEATTLE, WA · 2064236089
- ABBOTT CONSTRUCTION LLC · 3408 1ST AVE S # 101, SEATTLE, WA · 2064678500
- ACME CONSTRUCTION SUPPLY CO INC · 4747 1ST AVE S, SEATTLE, WA · 5038729805
- ACTION INDUSTRIES · 2417 10TH AVE E, SEATTLE, WA · 2063108463
Get free quotes from Seattle, WA pros →
Data by Servik — verified local pros from official license records and public sources. Cost figures are typical ranges, not quotes; a pro's written estimate is the real number.