Deck Building Cost in Washington (2026)
Deck Building in Washington runs about 15% above the national average. A typical 320 sq ft project starts around $5,520–$9,200 for pressure-treated wood. Estimate your exact project below.
Washington runs above the national average on cost, driven by a strong Seattle-area labor market and a higher cost of living west of the Cascades.
Reviewed by the AnyCoster Research Team · How we estimate costs
Deck Building Cost Calculator
Adjust the details for an installed-cost range tailored to you.
Length × width of the deck surface. A 16×20 deck is 320 sq ft.
Ballpark estimate for planning — not a quote.
Get your exact price from local deck pros
This is a ballpark — compare up to 3 free, no-obligation quotes from vetted contractors in Washington.
Deck Building cost in Washington by material
Installed cost for a typical 320 sq ft project in Washington.
| Material | Per sq ft | Typical WA project |
|---|---|---|
| Pressure-treated wood | $17.3–$28.7 | $5,520 – $9,200 |
| Cedar / redwood | $28.7–$46.0 | $9,200 – $14,720 |
| Composite (Trex-style) | $34.5–$69.0 | $11,040 – $22,080 |
What affects your Washington cost
- Decking material and railing style
- Height off the ground and stairs
- Footings, framing and permits
- Built-ins (benches, pergola, lighting)
- Local labor rates
Deck Building in Washington: local factors that move the price
Climate & weather
Wet, mild winters west of the Cascades bring persistent rain, so drainage, rot resistance, and mold-resistant finishes are essential, while the drier east is hotter and sunnier. Seismic risk is a significant regional concern.
Regional norms in Washington
Wood and fiber-cement siding with pitched roofs and robust gutter systems suit the wet western climate.
Best time to schedule
The drier summer months are strongly preferred for exterior work west of the Cascades.
Permits & code
Washington enforces a statewide code with strong energy provisions, and permits are generally required for structural, roofing, and electrical work, with seismic considerations in construction.
Washington deck building — FAQ
How much does deck building cost in Washington?
In Washington, a typical 320 sq ft deck building project runs about $5,520–$9,200 for pressure-treated wood, installed. That's about 15% above the national average. Higher-end materials cost more — use the calculator above for your exact size and material.
How much does deck building cost per sq ft in Washington?
In Washington, installed deck runs about $17.3–$69.0 per sq ft depending on material (pressure-treated wood $17.3–$28.7, cedar / redwood $28.7–$46.0, composite (trex-style) $34.5–$69.0). That's about 15% above the national average.
Do I need a permit for deck building in Washington?
Washington enforces a statewide code with strong energy provisions, and permits are generally required for structural, roofing, and electrical work, with seismic considerations in construction. Always confirm requirements with your local building department, and factor permit time and inspections into your schedule.
When is the best time to do deck building in Washington?
The drier summer months are strongly preferred for exterior work west of the Cascades. Wet, mild winters west of the Cascades bring persistent rain, so drainage, rot resistance, and mold-resistant finishes are essential, while the drier east is hotter and sunnier. Seismic risk is a significant regional concern.
How much does it cost to build a deck in 2026?
A typical 320 sq ft deck runs about $5,000–$8,000 in pressure-treated wood, or $10,000–$19,000 in composite, installed. Size, height, railings and material drive the price — use the calculator for a localized estimate.
Is composite decking worth it?
Composite costs roughly 1.5–2× wood up front but eliminates staining/sealing and lasts 25–30+ years, so total cost of ownership is often lower. It's the popular choice for homeowners who don't want annual maintenance.
Top cities in Washington
Metro-level deck building costs — usually a bit above the Washington state average.