A 16 × 12 ft pressure-treated deck, 3 ft high, with a wood railing and five steps costs about $10,400 to have built at US average prices, within a range of $6,200 to $14,600, or roughly $54 per square foot all in. Building it yourself leaves about $3,650 of materials. The same deck in composite with a composite railing comes to about $16,000.
How the deck cost is estimated
The price is built from line items, each a quantity times a US-average unit cost split into materials and labor:
Cost = Σ quantity × (material price × state material factor + labor price × state labor factor)
The quantities come from the deck itself. Square footage drives decking, framing and labor. The number of footings comes from the same IRC beam and post tables as the deck calculator, sized for treated pine joists 16 in on center. Stairs get one step per 7¾ in of height, the maximum riser in IRC R311.7.5.1. The railing runs along the open sides, less a 36 in stair opening. Your state scales labor by construction wages (BLS) and materials by regional goods prices (BEA). Check "I'll build it myself" and every labor line drops out.
Worked example: 16 × 12 ft treated pine
| Line | Quantity | Typical |
|---|---|---|
| Treated pine decking | 192 sq ft × $3.50 | $672 |
| Framing lumber and hardware | 192 sq ft × $8 | $1,536 |
| Building the frame and decking | 192 sq ft × $25 labor | $4,800 |
| Concrete footings | 3 × ($100 + $175 labor) | $825 |
| Wood railing | 37 ft × ($12.50 + $27.50 labor) | $1,480 |
| Stairs | 5 steps × ($62.50 + $75 labor) | $688 |
| Building permit | lump sum | $365 |
| Total | $10,366 |
The low and high columns use the ends of every range: $6,155 and $14,576, shown rounded as $6,200 and $14,600.
Unit costs behind the estimate
| Item | Low | Typical | High | Source |
|---|---|---|---|---|
| Treated pine decking, per sq ft | $2 | $3.50 | $5 | HomeAdvisor, June 2026 |
| Cedar decking, per sq ft | $3 | $5 | $7 | HomeAdvisor, June 2026 |
| Composite decking, per sq ft | $12 | $17 | $22 | HomeAdvisor, June 2026 |
| PVC decking, per sq ft | $5 | $10 | $15 | HomeAdvisor, June 2026 |
| Building labor, per sq ft | $15 | $25 | $35 | HomeAdvisor, June 2026 |
| Framing materials, per sq ft | $3 | $8 | $13 | Fixr, January 2023 |
| Poured footing, each (installed) | $200 | $275 | $350 | Fixr, January 2023 |
| Wood stair step (installed) | $75 | $137.50 | $200 | Fixr, January 2023 |
| Wood railing, per ft (installed) | $30 | $40 | $50 | Fixr, January 2023 |
| Composite railing, per ft (installed) | $80 | $122.50 | $165 | Fixr, January 2023 |
| Permit | $230 | $365 | $500 | HomeAdvisor, June 2026 |
| Tear-out of an old deck, per sq ft | $5 | $10 | $15 | HomeAdvisor, June 2026 |
HomeAdvisor lists PVC decking boards below composite ones ($5 to $15 against $12 to $22 per sq ft), and Fixr does the same; we use their figures as published. HomeAdvisor also quotes framing labor at $9 to $12 per sq ft "additional"; we do not add it on top of the $15 to $35 building labor, because that total already lands inside HomeAdvisor's own $5,400 to $10,800 for a 12 × 16 ft deck.
What moves the price most
Material. Decking boards are only part of the bill: switching this deck from treated pine to composite adds about $2,600 for boards but the frame, footings and labor stay the same. Composite railing is the bigger jump, three times the price of wood per foot.
Height. A deck more than 30 in above the ground needs a guard at least 36 in high on every open side (IRC R312.1), and every extra 7¾ in of height adds a step.
Tear-out. Replacing an old deck adds $5 to $15 per sq ft of labor before the new one starts.
Doing it yourself. Labor is about two thirds of the example. A DIY build still pays for materials, the permit and the concrete, and it is your time that fills the rest: the deck calculator lists every board, bolt and bag.
Plan it before you price it
The deck board calculator shows how many boards of each length your deck takes, which is where composite prices bite. The stair calculator lays out the stringers, and the deck stain calculator adds up the stain for a wood deck, railing and steps. Footings in concrete are priced per yard in the concrete cost calculator.