Deck Building Cost: Per Square Foot, by Size and Material
Decks are priced by area, then again by railing and foundation. This calculator prices the deck; railings and stairs are quoted separately in most contracts.
Estimate calculator
Estimate calculator
Decking and framing only. Railing adds $30 to $210 per linear foot, stairs $75 to $450 per step, and footings $50 to $500 per post.
By size
| Dimensions | Area | Installed cost |
|---|---|---|
| 8 × 10 | 80 sq ft | $1,200 – $4,400 |
| 12 × 12 | 144 sq ft | $2,160 – $7,920 |
| 10 × 16 | 160 sq ft | $2,400 – $8,800 |
| 10 × 20 | 200 sq ft | $3,000 – $11,000 |
| 12 × 20 | 240 sq ft | $3,600 – $13,200 |
| 14 × 20 | 280 sq ft | $4,200 – $15,400 |
| 16 × 20 | 320 sq ft | $4,800 – $17,600 |
| 20 × 20 | 400 sq ft | $6,000 – $22,000 |
A 16 by 20 deck is the most common size in the country at 320 sq ft, and it is the reference point every deck builder quotes from.
The per-square-foot price falls slowly as the deck grows, because the foundation and the framing do not scale linearly even though the decking does.
By material
| Material | Per sq ft installed |
|---|---|
| Pressure-treated wood | $15 – $25 |
| Vinyl | $17 – $33 |
| Cedar or redwood | $19 – $38 |
| Metal | $21 – $35 |
| Composite | $28 – $40 |
| Exotic hardwood (ipe) | $30 – $55 |
Pressure-treated pine is the cheapest and needs the most maintenance. Composite costs roughly twice as much up front and needs almost none.
The gap between them is not as large as people expect per square foot, but on a 320 sq ft deck it is several thousand dollars.
The railing problem
| Railing | Per linear ft | 72 ft perimeter |
|---|---|---|
| Wood | $30 – $50 | $2160 – $3600 |
| Metal | $45 – $85 | $3240 – $6120 |
| Composite | $80 – $165 | $5760 – $11880 |
| Cable | $115 – $175 | $8280 – $12600 |
| Glass | $140 – $210 | $10080 – $15120 |
This is the line item that surprises people. Railing is priced by the linear foot, not the square foot, and on a 320 sq ft deck the perimeter is about 72 linear feet.
At $30 to $210 per linear foot, railing alone can run $2,160 to $15,120 — which on the cheap end of the deck range is as much as the deck itself.
The cheapest railing and the most expensive railing differ by seven times, for the same perimeter. If your budget is tight, the railing material is a bigger lever than the decking.
The foundation decision
| Foundation | Installed per unit |
|---|---|
| Concrete deck blocks | $50 – $150 |
| Buried post | $100 – $300 |
| Poured concrete footer | $200 – $350 |
| Screw piles | $250 – $400 |
| Stackable precast forms | $250 – $500 |
A deck sits on posts, and the posts are what fails first.
Deck blocks on grade are the cheapest and are only appropriate for a low, unfastened platform. A raised deck attached to the house needs buried posts below the frost line, and a deck that will hold a hot tub needs poured footings sized for the load.
Do not economise here. Re-doing a foundation means removing the deck.
What it returns
Published cost-versus-value figures put a wood deck at 65.8% returned and a composite deck at 63% — below kitchens and bathrooms, and roughly in line with siding.
That is a reasonable return for an outdoor project, and the enjoyment value is not in the number.
What it costs in six states
Material does not change at the state line. Labour does. These are the same 240 sq ft job priced with six different wage markets.
| State | Labour factor | Low | High |
|---|---|---|---|
| Oklahoma | ×0.79 | $3,674 | $12,139 |
| Kentucky | ×0.84 | $3,791 | $12,567 |
| West Virginia | ×0.92 | $3,942 | $13,119 |
| New Hampshire | ×1.08 | $4,250 | $14,252 |
| New Jersey | ×1.38 | $4,846 | $16,437 |
| Illinois | ×1.40 | $4,894 | $16,611 |
Only the labour line moves. That is a stated limitation of this model, not an oversight.
Frequently asked
Deck or patio?
A patio is built on grade and costs far less: $3,000 to $8,000 against $9,000 to $20,000 for a deck. A deck is worth it when the ground slopes away from the house or you want to be level with an upper floor.
Do I need a permit?
In most areas yes, at $100 to $500. A deck is an addition to the structure and is inspected for framing and footings.
How long does a deck last?
Ten to fifteen years for untreated or poorly maintained wood, twenty for composite, longer for both with annual cleaning and sealing.
Updated October 2026