Composite decking costs a national average of $8,500 installed in 2026, with most homeowners spending $5,400 to $11,500, per Angi1. HomeGuide, a separately dated source (February 2026), publishes a wider installed framing of $40 to $80 per square foot including the substructure — $5,750 to $11,500 for a 12×12 deck and $16,000 to $32,000 for a 20×202. HomeAdvisor prices the Trex brand specifically, and its figures appear below only where they are labeled Trex3. Figures below are the latest published data from each source.
Cost by deck size
Both publishers price by size. Angi’s rows come from its $15 to $32 per-square-foot band (materials $5 to $18 plus labor $10 to $14), while HomeGuide’s rows include the substructure and apply to attached ground-level and elevated decks12:
| Deck size | Angi | HomeGuide (incl. substructure) |
|---|---|---|
| 10×10 (100 sq ft) | $1,500–$3,200 | $4,000–$8,000 |
| 12×12 (144 sq ft) | $2,200–$4,600 | $5,750–$11,500 |
| 16×16 (256 sq ft) | $3,800–$8,200 | $10,250–$20,480 |
| 16×20 (320 sq ft) | $4,800–$10,200 | — |
| 18×20 (360 sq ft) | $5,400–$11,500 | — |
| 20×20 (400 sq ft) | $6,000–$12,800 | $16,000–$32,000 |
| 20×24 (480 sq ft) | $7,200–$15,400 | $19,200–$38,400 |
| 23×23 (529 sq ft) | $7,900–$17,000 | — |
HomeGuide’s installed bands run higher than Angi’s on every shared size; the named scope difference is that HomeGuide’s figures include the substructure while Angi prices the substructure among its additional materials (below). Angi adds that small projects can start around $1,500 and large custom builds can exceed $20,0001.
Installed cost by deck type
HomeGuide’s per-square-foot figures by design type, substructure included2:
| Deck type | Installed cost per sq ft |
|---|---|
| Detached / floating (no railings or stairs) | $30–$40 |
| Ground-level / platform (attached) | $40–$50 |
| Elevated (attached) | $50–$80 |
| Second-story (attached) | $80–$100 |
| Multi-level (attached) | $90–$130 |
Material types and prices
Angi splits composite into three material types, priced as materials1:
| Composite type | Materials per sq ft (Angi) |
|---|---|
| PVC (vinyl) | $5–$15 |
| Mineral-based (polypropylene) | $6–$15 |
| Wood-plastic composite | $10–$18 |
HomeGuide’s materials band for the deck as a whole, including the base, is $16 to $32 per square foot2. On the brand side, HomeAdvisor’s Trex page prices that manufacturer’s three board series as materials: Trex Enhance $5 to $7, Trex Select $7 to $9, and Trex Transcend $10 to $12 per square foot, each carrying a 25-year limited warranty3. It puts Trex materials plus a basic substructure at $10 to $27 per square foot3.
Labor
The labor estimates differ by publisher: Angi puts installation labor at $10 to $14 per square foot ($3,600 to $5,000 on a 360-square-foot deck, with stairs at around $25 per square foot), while HomeGuide publishes $24 to $48 per square foot and says composite commands more labor than wood because of its extra parts and assembly care — presented as published12. HomeAdvisor’s Trex-specific labor figures: $8 to $22 per square foot for a basic install, rising to $15 to $35 for complex projects with framing, railings and stairs, with a basic board replacement taking one to three days and complex builds around a week3.
Substructure, railings and extras
Angi budgets the components beyond the boards at $10 to $23 per square foot, or $3,800 to $8,300 on a 360-square-foot deck1:
| Component | Cost (360 sq ft deck, Angi) |
|---|---|
| Railing | $875–$2,800 |
| Substructure | $1,900–$3,100 |
| Posts | $750–$1,900 |
| Hardware | $250–$500 |
| Total | $3,800–$8,300 |
HomeGuide prices railing at $20 to $60 per linear foot for wood or vinyl, new deck stairs at $1,400 to $2,600 installed ($500 to $1,500 to replace existing stairs when the structure is sound), yard leveling at $500 to $1,000, a new drainage system at $1,000 to $4,000, and a pea-gravel base at $0.85 to $2.80 per square foot delivered and installed2. Trex-branded add-ons from HomeAdvisor: RainEscape under-deck drainage $2.50 to $4 per square foot installed, lattice panels $195 to $960 each, outdoor lighting $15 to $110, and Trex railings $20 to $60 per linear foot3. See our deck railing cost guide for a full railing breakdown.
Demolition and replacement
Replacing an existing deck adds demolition at $5 to $15 per square foot, per Angi, bringing a combined tear-out-and-rebuild to $20 to $47 per square foot ($7,200 to $17,000 on an average deck), plus about $250 for debris hauling1. For repair pricing, see our deck repair cost guide.
Permits
Whether a deck needs a permit depends on your local building authority and the project scope, so confirm requirements with your municipality before work starts. For budgeting, published permit-fee estimates run $225 to $500 (Angi) and $50 to $150 (HomeGuide)12.
Related cost guides
Start with the full deck cost guide, then compare deck railing, deck repair and deck staining costs. Nearby structures: pergola cost, gazebo cost and patio cost.
The bottom line
Budget $5,400 to $11,500 for a typical composite deck on Angi’s figures, averaging $8,500, or $40 to $80 per square foot with the substructure included on HomeGuide’s. Material type and deck size drive the total, per both publishers’ factor lists, and the substructure, railings, stairs and any demolition can add as much as the boards themselves — so get at least three itemized quotes that separate boards, substructure, labor, railings, permits and tear-out.
Sources (each fetched and read October 26, 2026; figures are each publisher’s latest published data):
1. Angi, “How Much Does Composite Decking Cost? [2026 Data]” (updated September 29, 2026) — angi.com/articles/how-much-does-composite-decking-cost.htm
2. HomeGuide, “How Much Does Composite Decking Cost? (2026)” (February 10, 2026) — homeguide.com/costs/composite-decking-prices
3. HomeAdvisor, “How Much Does Trex Decking Cost?” (updated June 17, 2026; brand-specific page) — homeadvisor.com/cost/outdoor-living/install-trex-decking