A new deck in 2026 costs $30–$75 per square foot installed, or roughly $9,000–$30,000 for a typical 300 sqft deck. The range is wide because seven different cost buckets drive the total — and only one of them is the decking boards.
On a mid-tier composite deck, here's how $16,000 breaks down:
This is the visible top layer. Pressure-treated pine runs $2–4 per sqft of board, cedar $4–7, composite $5–9, PVC $8–12, and tropical hardwoods $10–16. Most homeowners underestimate hardware — hidden fasteners for composite add another $1.50–$3.00 per sqft.
Nearly every deck uses pressure-treated lumber for framing regardless of the decking material — PT joists last 20+ years underneath and are far cheaper than framing in hardwood. Expect $8–14 per sqft of deck for framing material plus labor. Taller decks, longer spans, and multi-level builds push this number up.
Every post needs a footing that reaches below the frost line (or onto bedrock). In warm states, 24-inch concrete piers cost $150–200 each. In frost states (Minnesota, New England, Upper Midwest), 48-inch frost footings run $230–300 each. Rocky soil may require helical piles at $300–500 per pile but no concrete pour.
A 300 sqft deck typically needs 4–6 footings. Multi-level or high decks need more.
Required by code on any deck over 30 inches above grade. Cost per linear foot installed:
Stairs are expensive on a per-foot basis — each step requires framing, treads, risers, and typically a handrail. Budget $130–250 per step. A deck 4 feet off the ground needs roughly 5 steps; a deck 6 feet off the ground needs 8.
Labor is 20–35% of total depending on state. Texas, Georgia, and Mississippi run 80% of national averages. California, New York, and Massachusetts run 25–40% above. A 300 sqft deck takes a 2-person crew 7–12 working days. See state-by-state pricing for the full dataset.
Required almost universally for decks over 30 inches or attached to the house. Most jurisdictions charge $100–400. High-cost states (California, New York, Massachusetts) can exceed $500. Inspections happen at the footing stage and final. Skipping permits can force demolition when you sell.