Ipe vs Cedar vs Composite — Cost Comparison for Seattle
Three materials, three installed bands, three PNW lifecycle paths. Side-by-side comparison with CITES context on Ipe, 25-year lifecycle math, and the 2026 reality layer applied.
2026 Deck Cost Estimator
Directional range based on material tier, slope condition, jurisdiction, and current site state. Built from 2026 PNW dealer-installed cost data.
$18,400 – $46,000
Range covers materials and labor before permit fees, Washington 10.35% retail sales tax, and any project-specific engineering. We refine to a single open-book number after site visit and structural review.
Seattle SDCI valuation-based; SFI permits ~40% of plan review fee. Typical deck permit fee band runs $400-$1,800; ECA-overlay decks add geotech review costs separately. 2025-2026 saw inflation-adjusted hourly rates rise materially.
Range includes January 2026 Trex/TimberTech repricing — composite Signature and Transcend lines were lifted +7-15% YoY per manufacturer notices. Cost guides published before Q4 2025 do not reflect this adjustment.
Estimates are directional only. Final pricing requires site visit, structural review, and permit feasibility check. Slope and ECA conditions in particular shift the band substantially after stamped engineering enters the scope.
Side-by-side cost and PNW context
Three materials behave differently in Greater Seattle’s weather, regulatory, and supply context. The table below draws on 2026 national installed-cost medians (HomeGuide / Angi) and PNW dealer-installed benchmarks and applies the January 2026 Trex/TimberTech repricing on the composite line.
| Field | Ipe | Cedar (WRC) | Capped composite |
|---|---|---|---|
| Installed cost ($/sqft, flat lot) | $110 – $180 | $30 – $90 | $75 – $130 |
| Installed cost ($/sqft, slope / ECA) | $140 – $260 | $45 – $130 | $100 – $190 |
| PNW lifespan | 25 – 40 years | 15 – 25 years | 25 – 50 years |
| PNW maintenance | Annual oil; greys naturally if left untreated | Reseal every 1-3 years; high to maintain warm tone | Annual rinse; no reseal |
| Supply / regulatory context | CITES Appendix II since 2022 — supply tightening, paperwork burden, ethical scrutiny | Domestic; PNW-milled options available | Jan 2026 Trex / TimberTech repricing +7-15% applied |
| Best PNW fit | Architect-led waterfront; exposed top-storey decks | Traditional regional aesthetic; covered or partial-cover sites | Slope, ECA, shaded, north-facing, low-maintenance briefs |
Sources: HomeGuide / Angi 2026 installed-cost data; PNW dealer-installed benchmarks; January 2026 Trex repricing. Ipe CITES status per CITES Appendix II listing.
Lifecycle cost over 25 years
Installed cost is the headline. Lifecycle cost is the truer comparison — particularly on a 500 sqft deck in PNW conditions where moisture and overcast UV exposure dictate maintenance burden. Numbers below assume a flat lot, no ECA overlay, and no mid-life structural replacement.
| Build (500 sqft) | Upfront | Annual | 25-year total |
|---|---|---|---|
| Western Red Cedar (500 sqft, flat lot) | $15,000 – $45,000 | $400 – $700 reseal-amortized | $25,000 – $62,500 |
| Capped composite — Trex Select (500 sqft, flat lot) | $37,500 – $50,000 | $80 – $150 cleaning | $39,500 – $53,750 |
| Capped composite — Trex Transcend Lineage (500 sqft, flat lot) | $50,000 – $65,000 | $100 – $200 cleaning | $52,500 – $70,000 |
| Ipe (500 sqft, flat lot) | $55,000 – $90,000 | $300 – $500 oil application | $62,500 – $102,500 |
| Thermally modified ash / garapa (500 sqft, flat lot) | $55,000 – $90,000 | $250 – $450 oil application | $61,250 – $101,250 |
Cedar reseal cost amortized across 1-3 year cycle. Composite cleaning cost assumes annual rinse and no major refinishing. Ipe oil cycle assumes annual application to maintain color; many PNW Ipe owners allow natural greying and skip the oil. Cost guide source: HomeGuide / Angi 2026; PNW lifespan source: PNW dealer-installed benchmarks.
Ipe and the CITES context
Ipe (Brazilian walnut, Handroanthus spp.) was added to CITES Appendix II in 2022. The listing does not ban international trade but adds permitting and traceability requirements on every shipment from the country of origin and the importing country. PNW dealers report tightening supply, intermittent stock-outs, and rising freight costs through 2025-2026. Architect-led PNW projects increasingly substitute thermally modified ash or garapa, both of which match Ipe’s density and PNW durability without the CITES paperwork burden.
Where Ipe is specified by name in a project (legacy match to existing structures, architect preference, or established residential aesthetic), we source from CITES-documented suppliers only and disclose certificate numbers in the open-book quote. Lead times typically run 4-8 weeks longer than composite. Where the design intent allows substitution, we present thermally modified ash and garapa as default Ipe alternatives in the feasibility consult.
The 2026 reality — how each tier moved
The 18-month window from Q1 2025 through Q2 2026 was unusual: four discrete shocks moved every tier upward at the same time, but not by the same amount. Composite moved more than wood on materials (the Trex/TimberTech repricing was tier-specific) and wood moved more than composite on labor (PNW carpenter wages rose with regional construction tightness). Net result — the band between cedar and composite narrowed.
Permit fees apply across every tier. King County (unincorporated) raised deck permit fees +49% on January 1, 2025 (Ord. 19857), then another ~14% on January 1, 2026 (Ord. 20021), plus a new $126 application screening fee. Seattle SDCI inflation-adjusted hourly billing rates rose +12-19% in 2025 and +18% in 2026. WA-specific 42-inch guard requirement and IRC R507.10 continuous-load-path rules under the 2021 IRC adoption (March 15, 2024) shifted railing system selection and stamped-engineering scope on every deck above 30 inches, regardless of finish material.
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.
Frequently asked
- Do I need a permit no matter which material I choose?
- Yes. The permit attaches to the structure, not the finish material. Seattle requires a permit on any deck more than 18 inches above grade, any roof deck, and any deck in an ECA overlay. King County, Bellevue, and Pierce County use 30 inches. Whether you build in Ipe, cedar, or capped composite makes no difference to the permit threshold.
- Why is Ipe more expensive in 2026 than the cost guides from a few years ago?
- Ipe entered CITES Appendix II in 2022. Each shipment now requires permits from the country of origin and the importing country, supply has tightened, and PNW dealers regularly run out of mill-direct boards. Architect-led projects increasingly substitute thermally modified ash or garapa — same density and durability, no CITES burden. Where Ipe is specified by name, expect $110-$180/sqft installed in 2026, with lead times on stock that can extend 4-8 weeks beyond composite.
- What is the difference between $40/sqft and $120/sqft installed?
- Three factors compound. First, material tier: pressure-treated pine boards run $2-$6/sqft material; capped composite or Ipe boards run $10-$25/sqft. Second, structural complexity: flat-lot concrete pier substructure runs $18-$24/sqft; slope or ECA helical pile substructure runs $30-$55/sqft. Third, railing: a basic pressure-treated guard runs $50-$100/linear ft; cable, glass, or premium aluminum at the WA 42-inch spec runs $100-$250/linear ft. Both ends of the band are legitimate — they describe different decks.
- How much does the WA 42-inch guard requirement add to cost?
- Modest at the material level (typically $300-$900 on a 60-linear-foot perimeter versus the IRC 36-inch baseline) but meaningful on architect-led projects that specify cable, glass, or aluminum railing systems. It also pushes stamped-engineering scope on the post connections at the 42-inch point of force per IRC Section R507.10 continuous load path.
- Composite lasts longer in PNW — does that make it cheaper in lifecycle terms?
- Yes against cedar; mixed against Ipe. A 500 sqft Trex Select build at $40,000 installed with $100/yr cleaning runs roughly $42,500 over 25 years. A 500 sqft cedar build at $25,000 installed with $500/yr reseal-amortized runs roughly $37,500 over 25 years — cheaper, but the cedar typically needs board replacement at year 18-22. Ipe lasts 25-40 years and costs $70,000-$90,000 installed; the lifecycle math favors composite or thermally modified hardwood for the same exposed-PNW context.
- Which material is most appropriate for a covered slope deck in West Seattle?
- On a covered slope deck (which describes a large share of West Seattle ECA-overlay projects), capped composite or capped polymer PVC is the default specification. Cedar in a covered slope context can hold up well but requires diligent reseal. Ipe is over-specified for covered sites — you pay for UV resistance you don’t need. The cost calculator above lets you toggle slope condition to see the band shift.
Material is a design decision. Cost is the side effect.
We walk through material selection with the architect, the homeowner, and the site condition in the room — not the cost guide. Open-book line-item pricing arrives once the material and substructure are specified, with CITES paperwork on Ipe and current manufacturer price sheets on composite attached as references.