Trex decking costs $28–$45 per square foot installed in Western Washington — depending on the collection you choose, your deck’s complexity, and whether you’re replacing an existing structure or building new.
Trex is the most widely specified composite decking brand in King County — and the most Googled. But pricing information online ranges from misleadingly low (material-only costs that leave out labor, permits, and demo) to frustratingly vague. This guide gives you real installed cost ranges for 2026, broken down by Trex collection, project type, and the variables that move the number up or down.
These ranges come from projects we’ve completed across Bellevue, Tacoma, Kirkland, and the broader Puget Sound area — not national averages that don’t reflect Pacific Northwest labor and permitting costs.
Quick Answer — Trex Decking Cost at a Glance
| Cost type | Range (per sq ft) | What’s included |
|---|---|---|
| Material only (boards) | $5–$13 per sq ft | Trex boards only — no labor, no framing, no fasteners |
| Installed — entry level | $28–$35 per sq ft | Trex Select or Enhance, standard ground-level build |
| Installed — mid-range | $35–$45 per sq ft | Trex Transcend, standard complexity, composite railing |
| Installed — elevated/complex | $45–$65+ per sq ft | Trex Transcend, hillside lot, custom railings, multi-level |
| Demo of existing deck | +$3–$8 per sq ft | Demolition and haul-away of old structure |
| King County permits | +$500–$1,500 | Permit fees — required for most deck projects |
A 400 sq ft Trex Transcend deck in Bellevue with composite railing, standard complexity, and demolition of an existing structure typically runs $18,000–$26,000 all-in — including labor, materials, permits, demo, and cleanup. Material-only cost for the boards would be roughly $3,200–$5,200 of that total.
Trex Decking Cost by Collection
Trex offers three main decking lines — each with different pricing, performance specs, and aesthetics. Here’s what each costs and when each makes sense.
Trex Transcend
Premium line — most commonly specified for King County builds
- Material cost: $9–$13/sq ft
- Installed cost: $35–$65/sq ft
- Warranty: 25 years
Transcend is Trex’s flagship line and the one we most commonly spec for Bellevue and Eastside builds. It features the deepest wood-grain embossing, the widest color palette, and Trex’s most comprehensive fade and stain warranty. The capped polymer shell on all four sides provides the best moisture resistance of the three lines — important for Pacific Northwest conditions where boards are wet for 6+ months per year.
Most popular colors for PNW builds: Gravel Path, Spiced Rum, and Havana Gold — these read warm without absorbing excessive heat under Seattle’s summer sun and perform well under tree canopy coverage common in Eastside lots.
Trex Enhance
Mid-range line — good performance, limited color options
- Material cost: $6–$9/sq ft
- Installed cost: $30–$40/sq ft
- Warranty: 25 years
Enhance offers solid composite performance at a lower price point than Transcend. It’s available in two sub-lines: Enhance Basics (solid-color boards, no wood grain) and Enhance Naturals (wood-grain texture). Both are fully capped and carry the same 25-year warranty as Transcend. The tradeoff is a narrower color selection and less realistic wood aesthetics.
Best for: budget-conscious builds where performance matters more than premium aesthetics, or secondary deck areas like pool surrounds and service walks.
Trex Select
Entry-level line — basic composite at the lowest Trex price point
- Material cost: $5–$7/sq ft
- Installed cost: $28–$36/sq ft
- Warranty: 25 years
Select is Trex’s most affordable line. It’s a solid-color board with a smooth surface — no wood-grain texture. The capping and warranty are the same as the higher lines, but the aesthetic is more utilitarian. In the Pacific Northwest we specify Select primarily for commercial applications, under-deck areas, or projects where the lowest material cost is the primary constraint.
Worth knowing: Select is often the line quoted in the lowest Trex pricing you’ll see advertised. If you’re comparing contractor bids, verify which Trex line is specified — a Select quote and a Transcend quote are not comparable.
Trex Decking Cost by Project Type and Size
| Project type | Typical size | Trex Transcend — total installed | Trex Enhance — total installed |
|---|---|---|---|
| Small ground-level deck | 150–200 sq ft | $7,000–$13,000 | $5,500–$9,000 |
| Standard residential deck | 300–400 sq ft | $13,000–$22,000 | $10,000–$16,000 |
| Large deck with railing | 400–600 sq ft | $18,000–$35,000 | $14,000–$26,000 |
| Elevated hillside build | 300–500 sq ft | $22,000–$42,000 | $18,000–$32,000 |
| Multi-level deck | 500–800 sq ft | $30,000–$55,000+ | $24,000–$42,000 |
Ranges reflect King and Pierce County 2026 pricing for licensed, permitted projects including labor, materials, standard framing, and cleanup. Demolition of an existing deck and permit fees are additional.
What Drives Trex Decking Cost Up or Down
Variables that increase cost
- Lot slope and elevation — Hillside builds in Bellevue’s West Side or Somerset require engineered footings, taller posts, and more complex framing. This can add $8–$20 per sq ft over a flat-lot build of the same size.
- Railing choice — Trex composite railing adds $60–$120 per linear foot. Cable railing systems (which pair well with Trex decking) run $80–$150 per linear foot. Glass railing is $120–$200+.
- Demolition of existing deck — Removing an existing structure adds $3–$8 per sq ft depending on size and construction type.
- Stairs — Each stair run adds $800–$2,500 depending on length and railing requirements.
- Hidden fastener systems — Trex’s Hideaway fastener system (which gives a clean, no-screw surface look) adds $1–$2 per sq ft in material cost and modest labor time.
- Deck lighting, built-in seating, or pergolas — These are all additive costs on top of the base deck price.
Variables that decrease cost
- Ground-level builds — Flat lots with minimal post height significantly reduce framing complexity and cost.
- Existing framing in sound condition — If you’re replacing surface boards only (resurfacing) on sound existing framing, installed Trex costs drop to $15–$25 per sq ft since you’re skipping the framing rebuild.
- Choosing Enhance over Transcend — The material cost difference is $3–$6 per sq ft, which translates to $900–$2,400 on a 300 sq ft deck.
- Simple rectangular layout — Complex angles, curves, and custom patterns require more waste factor and labor time.
Material Cost vs. Installed Cost — The Real Difference
This is the most common source of confusion when researching Trex pricing. Material-only costs (boards alone) look like this:
| Collection | Material cost (boards only) | What’s not included |
|---|---|---|
| Trex Select | $5–$7 per sq ft | Labor ($15–$25/sq ft) · Framing · Fasteners · Joist tape · Railing · Footings · Permits · Demo · Cleanup |
| Trex Enhance | $6–$9 per sq ft | |
| Trex Transcend | $9–$13 per sq ft |
The Trex boards themselves typically represent only 25–35% of the total installed cost. Labor, framing, fasteners, railing, permits, and cleanup make up the remaining 65–75%. A quote for “$9 per sq ft Trex Transcend” is a material-only quote — the installed cost for the same project will be $35–$55 per sq ft.
When comparing contractor quotes, always confirm whether pricing is material-only or fully installed and itemized. Our full deck replacement cost guide breaks down every line item so you can evaluate bids accurately.
Pacific Northwest Cost Factors
National Trex pricing guides typically use U.S. average labor rates. In Western Washington, expect the following differences:
- Labor rates are 15–25% higher than national averages, reflecting King and Pierce County wage levels and cost of doing business.
- Permits are required and enforced — Bellevue, Seattle, Tacoma, and surrounding cities all require permits for deck construction. Add $500–$1,500 to any project estimate.
- Moisture-rated hardware is mandatory for long-term performance — standard steel corrodes in 3–5 years in our climate. This is a non-negotiable spec for any reputable contractor in the region.
- Slope premium is common — A significant portion of Bellevue and Eastside residential lots involve meaningful elevation changes, which adds engineering complexity and cost vs. flat-lot national averages.
Trex vs. Cedar — Total Cost Over 20 Years
- Initial install: $8,000–$12,000
- Sealing/staining every 2 yrs: $400–$800/cycle × 10 = $4,000–$8,000
- Board replacements over 20 yrs: $1,500–$4,000
- Likely full replacement at yr 18–22
- Total 20-yr cost: ~$15,000–$26,000+
- Initial install: $16,000–$22,000
- Annual cleaning: $150–$300/yr × 20 = $3,000–$6,000
- Board replacements: minimal to none
- Still performing at year 20 with 5+ years remaining warranty
- Total 20-yr cost: ~$19,000–$28,000
The premium for Trex Transcend over cedar — roughly $4,000–$10,000 upfront — narrows significantly over a 20-year period when maintenance costs are factored in. In Western Washington’s wet climate, that gap closes faster than in drier regions because cedar requires more frequent maintenance cycles to hold up.
For a full breakdown of how Trex compares to TimberTech, PVC, and cedar across all dimensions, our decking material options guide covers every option with PNW-specific performance data.
If you’re deciding between repair and a Trex replacement, our repair vs. replace guide walks through the financial framework for making that call.
Ready to get a real Trex decking quote for your Bellevue or King County project?
Orca Roofing & Exteriors is a licensed deck replacement contractor serving Bellevue, Tacoma, Kirkland, and the broader Puget Sound. We provide fully itemized estimates — labor, materials with specific Trex collection and color, permits, demo if applicable, and cleanup. No single-number bids. Request your free estimate →
FAQs — Trex Decking Cost
How much does Trex decking cost per square foot?
Trex boards (material only) cost $5–$13 per square foot depending on the collection — Select at the low end, Transcend at the high end. Fully installed with labor, framing, fasteners, and standard hardware, expect $28–$45 per square foot for most residential projects in King and Pierce County. Complex builds on sloped lots or with custom railings run $45–$65+.
What is the cost of a 400 sq ft Trex deck?
A 400 sq ft Trex Transcend deck installed in the Bellevue or greater Seattle area typically runs $16,000–$22,000 for a standard build, or $22,000–$32,000 for an elevated or more complex project. Add $500–$1,500 for permits and $1,200–$3,200 for demolition of an existing deck if applicable.
Is Trex worth the cost compared to wood?
Over a 20-year horizon in the Pacific Northwest, Trex Transcend and cedar are within $3,000–$6,000 of each other in total cost when maintenance is factored in. Trex’s advantage is zero maintenance beyond annual cleaning, a 25-year warranty, and no replacement cycle within that period. Cedar requires biannual sealing, board replacement, and typically a full rebuild at 18–22 years. For most homeowners who don’t want to maintain their deck, Trex wins on total cost of ownership.
What is the most expensive Trex decking?
Trex Transcend is the premium collection at $9–$13 per square foot for materials. The Transcend Lineage series (island-inspired color palette) sits at the top of the Transcend range. Installed costs for Transcend run $35–$65+ per square foot depending on project complexity.
How much does Trex decking installation cost in Bellevue or Seattle?
Labor and installation in King County typically runs $15–$25 per square foot on top of material costs — higher than national averages by 15–25% due to regional wage levels and permit requirements. Total installed cost for a standard Trex project in Bellevue or Seattle is $28–$45 per square foot for most residential builds.
Does Trex decking require permits in Washington State?
Yes. Deck construction and full replacements in Bellevue, Seattle, Tacoma, and surrounding King and Pierce County cities require building permits. Permits typically cost $500–$1,500 depending on project scope. A licensed contractor pulls permits on your behalf — any contractor who suggests skipping permits is creating liability for you at resale and with your homeowner’s insurance.
