How Much Does It Cost to Build a 12×12 Deck?
Quick Answer
A 12×12 deck is 144 square feet. Installed, it costs about $2,160 to $3,600 in pressure-treated wood or $4,320 to $6,480 in composite. A DIY build using material only costs far less.
- Pressure-treated: $2,160–$3,600 ($15–$25/sq ft)
- Cedar: $2,880–$5,040 ($20–$35/sq ft)
- Composite: $4,320–$6,480 ($30–$45/sq ft)
- Hardwood (ipe): $5,760–$8,640 ($40–$60/sq ft)
Formula
Deck building is priced per square foot installed, covering framing, decking, fasteners, and labor. Multiply the deck area by the per-square-foot rate for your material and construction type.
Step-by-Step Calculation
- 1
Deck area
12 × 12 = 144 square feet
- 2
Pressure-treated (installed)
144 × $15–$25 = $2,160–$3,600
- 3
Composite (installed)
144 × $30–$45 = $4,320–$6,480
- 4
Add features
Railings, stairs, and footings add to the base cost
12×12 Deck Cost by Material (144 sq ft, installed)
| Material | Cost per Sq Ft | 144 sq ft Total | Notes |
|---|---|---|---|
| Pressure-Treated Pine | $15–$25 | $2,160–$3,600 | Lowest cost, needs sealing |
| Cedar | $20–$35 | $2,880–$5,040 | Natural look, moderate upkeep |
| Composite | $30–$45 | $4,320–$6,480 | Low maintenance, long life |
| Hardwood (Ipe) | $40–$60 | $5,760–$8,640 | Premium, very durable |
Installed costs include framing, decking, and labor. Raised decks, stairs, railings, and permit fees add to the total. DIY material-only runs roughly 40–60% of these figures.
Frequently Asked Questions
Is it cheaper to build a deck yourself?
Yes. Labor is roughly half of an installed deck cost, so a DIY 12×12 deck in pressure-treated wood can cost $1,000–$1,800 in materials versus $2,160–$3,600 installed — if you have the tools and skills to build to code.
Does a 12×12 deck need a permit?
Usually yes, especially if it is attached to the house or raised above a certain height. Rules vary by locality — check with your building department, since an unpermitted deck can cause problems at resale.
How much do railings and stairs add?
Railings typically add $20–$60 per linear foot, and a short set of stairs adds $300–$1,000. A ground-level 12×12 deck without railings or stairs sits at the low end of the cost range.