Deck building costs range from $15 to $35 per square foot installed for a basic pressure-treated ground-level deck, and $35 to $70 per square foot for a composite deck with quality railing. The gap comes down to decking material, which also dictates railing choice, fasteners, and long-term maintenance. A 300-square-foot deck typically lands between $4,500 and $21,000 depending on material.
What drives deck building cost
Material choice swings the total more than anything else. Pressure-treated pine is the budget baseline at $15 to $25 per square foot installed. Cedar and redwood run $25 to $40, capped composite runs $35 to $60, and tropical hardwoods like ipe push $40 to $70. For a 300-square-foot deck, that spans $4,500 to $21,000 before railings and stairs.
Height is the second driver. A ground-level deck needs minimal framing, but anything you step up to requires concrete footings below the frost line, taller posts, and code-compliant stairs and railing—adding $3,000 to $8,000. The deck design ideas guide covers how single-level versus multi-tier layouts change framing complexity and labor.
Railings are the line item people forget. Pressure-treated wood railing runs $20 to $35 per linear foot, while aluminum or cable rail runs $40 to $60. A 300-square-foot deck often needs 40 to 50 linear feet, so railing choice alone is a $1,000 to $3,000 swing—see the deck railing ideas guide for options.
Labor is roughly a third of most budgets and scales with complexity more than size. Angled corners, multiple levels, picture-frame borders, and built-in benches all add hours. Labor rates and required footing depth vary by region, so get framing labor quoted against your actual site rather than a generic per-square-foot figure.
Maintenance is the cost that shows up after the build. A pressure-treated or cedar deck needs cleaning and re-staining every 2 to 3 years at $200 to $500 each time—several thousand dollars over twenty years. Capped composite needs only occasional washing, so its higher upfront price often evens out. Run the math over how long you'll own the house before assuming wood is cheaper.
A line-item deck budget
Here is a realistic mid-range composite deck, 300 square feet at ground level with stairs:
| Item | Cost |
|---|---|
| Capped composite decking, 300 sq ft | $5,400 |
| Pressure-treated framing, joists, ledger | $2,400 |
| Concrete footings and posts | $1,200 |
| Aluminum railing, 45 linear ft | $2,250 |
| Stairs, four steps with railing | $1,200 |
| Fasteners, flashing, hardware | $600 |
| Labor, framing through finish | $6,000 |
| Total | ~$19,000 |
Swap composite for pressure-treated pine and the same deck drops to roughly $11,000. Building above a walkout basement or sloped yard? The raised deck ideas guide covers the added footing depth and structural requirements that drive raised-deck budgets higher.
Size the deck to how you'll actually use it before the per-square-foot number tempts you bigger. A 300-square-foot deck comfortably seats a six-person dining set plus a small lounge zone; every additional 100 square feet adds $1,500 to $7,000 depending on material. Map your furniture onto the plan first, add a four-foot circulation margin, and let that define the size.
Accessories quietly inflate the final number: built-in lighting runs $400 to $1,500, a privacy screen or pergola adds $1,000 to $5,000, and a built-in bench or planter adds $500 to $2,000. Rough these into the plan early—retrofitting wiring or footings for a pergola after the deck is finished costs far more than building it in from the start.
Common mistakes to avoid
The most expensive mistake is skipping the permit. A deck is a structural element attached to your house, and an unpermitted deck can fail inspection at resale, void insurance after a collapse, and force a teardown.
- Comparing only upfront price. Wood's cleaning and re-staining costs ($200-$500 every 2-3 years) often make its twenty-year cost meet or exceed composite.
- Undersizing footings. Footings that don't reach below the frost line heave and rack the whole frame.
- Buying cheap fasteners. Uncoated screws rust and streak both wood and composite within a season.
Preview your deck before you build in Re-Design
Frequently Asked Questions
How much does it cost to build a deck?
A basic pressure-treated deck runs $15 to $35 per square foot installed, and a composite deck with quality railing runs $35 to $70. For an average 300-square-foot deck, that's roughly $4,500 to $10,500 in wood or $10,000 to $21,000 in composite.
Is composite or wood decking cheaper?
Wood is cheaper upfront—pressure-treated pine starts around $15 per square foot versus $35 or more for composite. But wood needs staining and sealing every 2 to 3 years, so over twenty years composite often costs the same or less while needing almost no maintenance.
Do I need a permit to build a deck?
Almost always, especially for any deck attached to the house or raised above ground level. A deck is a structural element, so building permits and inspections typically apply. Unpermitted decks create problems at resale and can void insurance after a structural failure.
How much does railing add to a deck budget?
Railing runs $20 to $35 per linear foot for pressure-treated wood or $40 to $60 for aluminum or cable rail. A typical 300-square-foot deck needs 40 to 50 linear feet, making railing a $1,000 to $3,000 line item in the overall budget.
