Deck & Patio Cost in Seattle, WA
Estimate your deck & patio budget in Seattle with local cost data. Average costs range from $18 to $92/sq ft.
Budget
$18
per sq ft
AVERAGE
Mid-Range
$43
per sq ft
High-End
$92
per sq ft
Deck & Patio Budget Calculator — Seattle
100 sq ft500 sq ft
0% (none)25% (generous)
Estimated Total for Seattle, WA
$14,190
300 sq ft × $43/sq ft$12,900
Contingency (10%)$1,290
Total Estimate$14,190
* Estimates are based on 2026 average costs for Seattle, WA. Actual costs may vary based on specific project requirements, contractor pricing, material selections, and permit fees.
About Deck & Patio in Seattle
Building or replacing outdoor decks and patios including framing, decking material, railings, and finishing.
Typical Duration
2–6 weeks
Cost Range (Seattle)
$18 – $92/sq ft
Frequently Asked Questions: Deck & Patio in Seattle
How much does a deck cost to build?
Deck construction costs $15–$75 per square foot. A 300 sq ft pressure-treated deck averages $10,000–$15,000, while composite decking costs $15,000–$25,000.
How long does it take to build a deck?
A standard deck takes 2 to 6 weeks. Simple ground-level decks can be completed in a week.
Do I need a permit for a deck?
Most municipalities require permits for decks above 30 inches from the ground or over 200 sq ft. Check local building codes.
Wood vs composite decking — which is better?
Composite costs more upfront but requires less maintenance and lasts 25-30 years vs 10-15 years for pressure-treated wood.
How should I budget for a deck project?
Get at least 3 contractor bids and add a 10% contingency. Use BuildLedger to compare bids side-by-side and track all costs throughout the project.
Track Your Deck & Patio Budget
BuildLedger helps you manage contractor invoices, track payments, and keep your remodel on budget — all in one place.