Deck Cost in Greater Seattle — 2026 Edition
Five cost guides for the Seattle, Bellevue, King County, and Pierce County markets — each tied to current permit fee schedules, the 2026 Trex and TimberTech repricing, Q2 2026 lumber moves, and WA-specific structural code.
We publish ranges, not hooks. Open-book pricing is our default posture: every page below explains the math, cites the source, and ends in a calculator plus a direct path to a feasibility consult.
The Five Guides
Comprehensive guideCost to Build a Deck in Seattle (2026)
The broadest entry to the cluster. Materials, labor, permits, sales tax, and 2026 reality layer applied to a representative 400 sqft project from scope through final inspection.
Read the guide →Material deep-diveTrex Deck Cost in Seattle (2026)
Why Trex Transcend Lineage lands at $80-$130/sqft installed in the Pacific Northwest, and how the January 2026 Trex repricing shifted the band. Pulled apart line by line.
Read the guide →Material categoryComposite Deck Cost in Seattle
Standard composite, capped composite, capped polymer PVC. Where the $40, $80, and $130 per sqft thresholds come from, and how they compare to cedar and pressure-treated framing in PNW lifecycle terms.
Read the guide →Per-sqft mathDeck Cost per Square Foot in Seattle
The most-asked question gets a full breakdown. Materials per sqft, labor hours per sqft, permit fees per sqft, sales tax per sqft, with a 500 sqft worked example.
Read the guide →ComparisonIpe vs Cedar vs Composite — Cost Comparison for Seattle
Side-by-side: installed cost band, PNW lifespan, maintenance burden, and CITES context on Ipe. Lifecycle cost over a 25-year horizon for each tier.
Read the guide →2026 Permit Fee Matrix
Four core Greater Seattle jurisdictions, their deck permit thresholds, and the 2026 fee schedules behind every quote you receive.
| Jurisdiction | Permit Threshold | 2026 Fee Structure | Recent Change |
|---|---|---|---|
| Seattle SDCI | >18" above grade; any roof deck; any deck in an ECA overlay | Valuation-based sliding scale. SFI (Subject-to-Field-Inspection) permits run ~40% of the plan review fee. 2026 Fee Code and Fee Estimator published. | +12-19% in 2025, +18% inflation-adjusted hourly rates in 2026 |
| King County (unincorporated) | >30" above ground (uncovered decks at or below 30" outside critical areas exempt) | $772 application review + $2.46/sqft inspection (deck of 500 sqft or less) + new $126 application screening fee | +49% on Jan 1 2025 (Ord. 19857), +~14% on Jan 1 2026 (Ord. 20021) |
| Bellevue | >30" above ground (plan review included in permit) | Valuation-based. Reported by local contractors as relatively faster and less painful than King County unincorporated. | No major fee-schedule shock reported through Q2 2026 |
| Pierce County (unincorporated) | >30" above adjacent grade; guardrail required on all decks >30" | $69 for the first $2,000 of valuation + $12.21 per additional $1,000 up to $25,000. Fast Track available for pre-designed single-level decks up to 14 ft high. | Updated effective Feb 1, 2026 (Pierce County Code 17C.10.070) |
Source: Seattle SDCI 2026 Fee Code; King County Ord. 19857 / 20021; Bellevue Development Services; Pierce County Code 17C.10.070. Threshold and fee data current as of Q2 2026. Final permit cost on any project depends on valuation, site conditions, and whether structural engineering or geotechnical review is triggered.
A deck quote you can read line by line.
We pull the permit in your name, share the SDCI or county tracking number on day one, and itemize every line — materials, labor hours at posted PNW carpenter rates, structural engineering, geotech, sales tax, and jurisdiction permit fees. No flat “starting at” hooks. No bid hooks.