Estimates are for planning purposes only and based on 2025 contractor data.
Always get at least 3 quotes before hiring. Prices vary by ZIP code, site conditions, and contractor availability.
Deck costs in Washington state are above the national average in 2026, particularly in the Seattle metro area. Expect to pay $24 to $42 per square foot for pressure-treated wood and $42 to $78 per square foot for composite decking. A standard 12×16 deck in Washington typically costs between $6,500 and $14,500.
Frequently Asked Questions
How much does a deck cost in Washington state in 2026?
Washington homeowners typically pay between $6,000 and $15,000 for a new deck in 2026. Seattle and Bellevue metro areas run significantly higher than eastern Washington cities like Spokane due to higher labor costs.
What is the best decking material for Washington state?
Composite decking is the top choice for Washington due to the regions heavy rainfall and moisture. Western red cedar is also a popular local option as it is naturally rot-resistant and holds up well in wet climates.
Do I need a permit to build a deck in Washington state?
Yes, Washington requires building permits for most deck projects. Seattle has detailed requirements including structural calculations. Permit costs range from $200 to $1,000 depending on your city or county.
How does rain affect deck construction in Washington?
Washington gets significant rainfall particularly west of the Cascades. This makes moisture-resistant materials critical. Composite decking, proper drainage design, and quality sealants on any wood components are essential for long-term durability.