How Much Does a Deck Cost in Seattle? (2026 Guide)

The five biggest drivers of deck cost in Seattle: 1. Size (square footage) — The most obvious factor. Most decks are 200–500 sq ft. Every 100 sq ft adds roughly $3,000–$6,000 depending on material. 2. Material choice — Cedar is the most affordable natural option. Entry composite (Trex Enhance) costs about the same as cedar but lasts longer. Premium composite (Trex Transcend) costs 40–60% more than cedar upfront but has zero maintenance. 3. Height off grade — A ground-level deck needs minimal framing. A deck 8+ feet off the ground requires significantly more structural lumber, larger posts, and more complex engineering. Height adds 20–40% to base cost. 4. Complexity — Simple rectangular decks cost less. L-shapes, multi-levels, built-in seating, pergolas, and wraparound designs add cost proportionally. 5. Permits — All attached decks or decks over 30" require permits in Seattle. We handle all permitting — it's included in our price.

Upfront cost is only part of the story. Here's a realistic 20-year cost comparison for a 300 sq ft deck: Cedar deck: • Initial cost: $14,000 • Staining/sealing every 2–3 years: $600 × 8 times = $4,800 • Board replacements over 20 years: ~$1,500 • Total 20-year cost: ~$20,300 Trex Select composite deck: • Initial cost: $9,600 • Maintenance: $100/year (occasional rinse) × 20 = $2,000 • No board replacements needed • Total 20-year cost: ~$11,600 In most cases, composite decking costs less over 20 years despite the higher initial price — and the maintenance savings are significant for Seattle's busy homeowners.

Deck pricing varies significantly based on your specific property — slope, access, existing structures, soil conditions, and HOA requirements all affect cost. We provide fixed-price quotes for every deck project — not ranges or "starting at" prices. Here's our process: 1. Free in-home consultation (45–60 minutes) 2. We measure your space and discuss your vision 3. You receive a written, itemized quote within 3 business days 4. Our quote includes materials, labor, permits, and cleanup No surprises. No change orders for "discovered issues." One price from estimate to final invoice. Call [PHONE] to schedule your free deck consultation.