The national average deck installation cost runs $20 to $60 per square foot installed in 2026, with 320 square foot pressure-treated decks averaging $7,500 and equivalent composite builds reaching $19,000 or more. Material choice drives 50 to 65 percent of total cost, while labor, footings, permits, and railings make up the rest. This guide breaks down realistic pricing across the four major decking materials, the line items that surprise homeowners, regional cost variation, and the upgrades worth paying for.
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Average Cost by Material
Decking material is the single largest variable in your quote. Expect roughly the following installed pricing for a 16 by 20 foot deck (320 square feet) including framing, fasteners, and basic railing.
- Pressure-treated pine: $20 to $30 per sq ft, $6,400 to $9,600 total
- Cedar: $25 to $38 per sq ft, $8,000 to $12,200 total
- Composite (Trex, TimberTech): $35 to $55 per sq ft, $11,200 to $17,600 total
- PVC (Azek, Wolf): $45 to $65 per sq ft, $14,400 to $20,800 total
- Tropical hardwood (Ipe, Cumaru): $40 to $65 per sq ft, $12,800 to $20,800 total
- Aluminum: $50 to $80 per sq ft, $16,000 to $25,600 total
Material Cost Breakdown
Decking boards alone account for 30 to 45 percent of total project cost. A 5/4 by 6 inch by 16 foot Trex Enhance Naturals board runs $42 at Home Depot, while the equivalent pressure-treated Southern Yellow Pine board is $14. The composite board lasts 25 plus years; the pressure-treated typically requires staining every 2 to 3 years and full replacement at 12 to 15 years.
Joists, beams, posts, and ledger boards add $1,200 to $2,800 in lumber for a 320 square foot deck depending on span requirements and post spacing. Stainless steel or coated structural fasteners add $200 to $500.
Labor Costs Across the Country
Labor accounts for 35 to 50 percent of installed cost. National average labor runs $15 to $35 per square foot, with significant regional variation. Expect to pay the high end in Boston, San Francisco, Seattle, and New York City, the low end in Mississippi, Alabama, and rural Texas.
A two-person crew typically completes a 320 square foot deck in 5 to 7 days. Complex decks with multiple levels, octagon corners, or built-in benches double the labor time and cost.
Permits, Inspections, and Engineering
Almost every U.S. jurisdiction requires a building permit for decks over 30 inches off the ground or larger than 200 square feet. Permit fees range from $150 to $750 based on project value and local rates.
Engineered drawings are sometimes required for decks attached to a primary residence, especially in California, Florida, and snow-load states. Engineering stamps run $400 to $1,200. Failure to permit before building risks fines, forced removal, and complications when selling the home.
Footings and Substructure Surprises
Concrete footings are the hidden cost that blows budgets. A 320 square foot deck typically requires 6 to 9 footings, each 12 inches in diameter and dug to local frost depth (24 inches in mild climates, 48 inches in northern Minnesota and Maine). Total footing cost: $400 to $1,200 in concrete and labor.
If you discover poor soil, buried utilities, or rock during digging, expect change orders of $500 to $2,500. Order a test pit dig before the project starts in older neighborhoods or near mature trees.
Railings, Stairs, and Add-Ons
A standard pressure-treated railing system runs $25 to $45 per linear foot installed. Aluminum or steel cable railings jump to $60 to $130 per linear foot. Glass-panel railings exceed $200 per linear foot.
- Standard pressure-treated stairs (4 risers): $400 to $800
- Composite stairs: $1,000 to $1,800
- Built-in bench seating: $400 to $1,200 per linear section
- Pergola or shade structure: $2,500 to $7,500
- Low-voltage stair and post lighting: $400 to $1,500
- Under-deck drainage system (Trex RainEscape): $9 to $15 per sq ft
DIY vs Contractor Cost Savings
Building a 320 square foot pressure-treated deck DIY runs $3,200 to $4,800 in materials, saving $3,500 to $5,000 in labor compared to a contractor build. Composite DIY runs $7,500 to $11,000 in materials versus $14,000 contractor.
Realistic DIY skills required: framing carpentry experience, accurate post layout, comfort with concrete footings, and a working understanding of joist spans and ledger flashing. Plan 7 to 14 weekend days for a beginner DIY build versus 5 to 7 days for a pro crew.
Hidden Costs Most Homeowners Miss
Demolition of an existing deck adds $5 to $10 per square foot, or $1,500 to $3,200 for a 320 square foot teardown. Dumpster rental adds $400 to $700.
Ledger flashing and house siding repair often runs $300 to $1,200 if the original ledger was improperly flashed. Properly flashed ledgers prevent water intrusion that can rot rim joists and band boards inside the home, a $5,000 to $15,000 repair if missed.
Long-Term Cost of Ownership
Pressure-treated decks need annual cleaning ($75 in supplies DIY) and staining every 2 to 3 years ($200 to $400 DIY, $800 to $1,500 contractor). Over 15 years, expect $3,000 to $5,500 in maintenance plus full replacement.
Composite and PVC decks need only annual cleaning with a soft brush and Trex deck cleaner ($25 per gallon). No staining, no sealing, and 25 to 50 year warranties make the higher upfront cost worthwhile if you plan to keep the home long-term.
Common Cost Pitfalls
Accepting the lowest bid without verifying license, insurance, and references is the top regret. Builder defaults, lien risks, and rebuild costs from incompetent work usually wipe out any savings. Get three written bids, check Angi or HomeAdvisor reviews, and confirm the contractor pulls the permit in their name.
