Cost to Composite Deck Building in Seattle, WA

$11,520–$28,160 in Seattle

28% above the national average · 1.28x cost multiplier

In Seattle, a composite deck building runs $11,520 to $28,160 on average — about 28% above what homeowners pay nationwide. The West Coast market's labor costs account for most of the gap, with material pricing and local permitting fees adding to the spread. Use the cost table below to compare budget, mid-range, and premium options side by side.

Cost Breakdown in Seattle

Line Item	Low	Mid	High
Cost per sq ft	$51	$70	$102
Materials	$5,760	$9,600	$17,920
Labor	$5,120	$9,600	$15,360
Permits	$320	$448	$640
Total	$11,520+28% vs. national avg	$20,480+28% vs. national avg	$35,840+28% vs. national avg

Budget

Entry-level composite (Trex Enhance or Fiberon), ground-level, basic railing, simple rectangular layout, $30-$45/sq ft for 300 sq ft

Mid-Range

Mid-tier composite (Trex Select or TimberTech), standard height, upgraded railing system, $45-$65/sq ft for 300 sq ft

Premium

Premium composite (Trex Transcend or Azek), multi-level or elevated, aluminum railing, built-in lighting, $65-$100+/sq ft for 300 sq ft

Material Options

Material prices below are national averages; availability in Seattle may shift costs slightly.

Material	Cost/Unit	Pros	Cons	Best For
Trex Enhance	$5-$7/sq ft (material)	Most affordable Trex line, good color selection, 25-year warranty	Less scratch resistance than premium lines, fewer color options	Budget-conscious builds where composite is preferred over woodMost affordable Trex line, good color selection, 25-year warranty
Trex Select	$7-$9/sq ft (material)	Better fade and stain resistance, more natural wood grain, 25-year warranty	Mid-range price, still not as premium as Transcend	Most popular mid-range choice, good balance of price and performanceBetter fade and stain resistance, more natural wood grain, 25-year warranty
Trex Transcend	$10-$14/sq ft (material)	Best Trex aesthetics, deep wood grain, superior scratch resistance, 25-year warranty	Premium pricing, heavy boards	Premium builds where appearance is a priorityBest Trex aesthetics, deep wood grain, superior scratch resistance, 25-year warranty
TimberTech / Azek	$7-$12/sq ft (material)	Capped polymer (Azek) is virtually maintenance-free, excellent color retention, 30-50 year warranties	Higher cost, Azek can feel less wood-like underfoot	Homeowners wanting maximum longevity and minimal maintenanceCapped polymer (Azek) is virtually maintenance-free, excellent color retention, 30-50 year warranties
Fiberon	$5.50-$9/sq ft (material)	Competitive pricing, solid warranty, good color options	Less brand recognition, fewer dealer options in some regions	Value-oriented builds, comparable quality to Trex at a lower priceCompetitive pricing, solid warranty, good color options

Other Projects in Seattle

Full Kitchen Remodel

Full Bathroom Remodel

Hardwood Floor Installation

Back to national average for Composite Deck Building

Seattle Estimate

Typical Range

$11,520–$28,160

vs. National Average

28% above national

Cost Multiplier

1.28x

Cost Per sq ft

$51–$102

Estimates apply Seattle's 1.28x regional cost multiplier to national averages. Actual bids vary by contractor, project scope, and timing.

See national average costs →