How Much Does a Wood Deck Cost Per Square Foot? Full Breakdown

Ask three contractors to price the same deck and you will get three different numbers — and all three can be honest. A wood deck is not one product with one price. It is a small structure: footings, framing, decking boards, railing, stairs, and a permit, and every one of those lines moves with the material you choose, the height of the deck, and how far the crew has to haul everything. This guide breaks the cost down line by line so you can read a quote and know exactly what you are paying for, then works a full example for a 16 ft × 20 ft deck in pressure-treated pine and in composite.

Wood Deck Cost at a Glance

For a straightforward, ground-level to mid-height deck built by a contractor in the United States, expect these installed ranges in 2026:

• Pressure-treated pine: $15–$25 per sq ft installed
• Cedar or redwood: $25–$35 per sq ft installed
• Composite decking: $30–$50 per sq ft installed
• PVC decking: $40–$60 per sq ft installed

Those figures cover the deck structure itself — footings, framing, decking boards, and labour. Railing, stairs, lighting, and permits sit on top. A 320 sq ft pressure-treated deck typically lands between $10,000 and $12,000 all-in, while the same deck in composite runs $15,000 to $18,000. The rest of this article shows where every dollar goes.

What Drives the Price Per Square Foot

Before comparing quotes, understand the five things that move the number most.

1. Decking material

The boards are the single biggest cost difference. Pressure-treated southern yellow pine is the cheapest decking board you can buy, roughly $2–$4 per sq ft for material alone. Cedar runs $5–$8 per sq ft. Composite boards cost $8–$15 per sq ft, and PVC $10–$18. The framing underneath is nearly identical whatever you put on top, so the board choice is what separates a $20 per sq ft deck from a $40 one.

2. Deck height and access

A deck 2 ft off the ground needs short posts, no railing on the low side in many jurisdictions, and simple stairs. A deck 8 ft up needs tall posts, full railing all round, a longer stair flight, and often diagonal bracing. Height alone can add $5–$10 per sq ft. Tight access — a steep backyard, no side gate for a truck — adds labour hours too.

3. Footings and soil

Every post needs a concrete footing carried below the local frost line, per the International Residential Code (IRC R403) and the footing provisions referenced in ACI 318. In warm climates that is 12 in. deep; in the northern US it can be 36–48 in. Rocky soil, a slope, or a footing that has to be dug by hand instead of an auger all add cost. Budget $150–$250 per footing.

4. Railing and stairs

Railing is priced per linear foot, not per square foot, and it is expensive: $30–$45 per lin ft for wood, $60–$90 for composite or aluminium. A deck with 50 lin ft of railing carries $1,500–$4,500 of railing alone. One flight of stairs adds $500–$1,000.

5. Permits and inspections

Most jurisdictions require a building permit for a deck attached to a house or more than 30 in. above grade. Permit fees typically run $150–$500, and the inspector will want to see the footings before concrete is poured and the framing before the boards go down. A contractor who skips the permit is not saving you money — he is handing you the liability.

Pressure-Treated Wood Deck Cost Breakdown

Pressure-treated pine is the workhorse of deck building: affordable, widely available, and strong enough for any residential deck when it is treated to the right retention level — UC3B for above-ground use, UC4A for ground contact, per the American Wood Protection Association standards. Its weakness is maintenance: it needs sealing every 1–2 years and will check, cup, and grey if neglected. Typical installed cost:

• Decking boards: $4.50 per sq ft ($2–$4 material, plus cutting and fastening)
• Framing lumber (joists, beams, posts): $3.00 per sq ft
• Footings: about $180 each; one footing per 50–60 sq ft of deck
• Fasteners and hardware: $1.00 per sq ft (screws, joist hangers, post bases, flashing)
• Labour: $10–$12 per sq ft

All-in, a pressure-treated deck with standard wood railing and one stair flight usually lands at $30–$35 per sq ft of deck area. The boards themselves are only about a fifth of the total — which is why switching to a premium board does not double the price of the whole job.

Composite Deck Cost Breakdown

Composite decking — wood fibre and plastic extruded into boards — costs more up front and far less over its life. No staining, no sealing, no splinters, and a 25–30 year warranty is standard from the major manufacturers. The trade-off is that composite boards are heavier, need closer joist spacing (12 in. on centre for diagonal layouts, versus 16 in. for wood), and require hidden fasteners. Typical installed cost:

• Composite decking boards: $14.00 per sq ft
• Framing lumber: $3.00 per sq ft (same as wood)
• Footings: about $180 each
• Hidden fasteners and clips: $2.00 per sq ft
• Labour: $12–$14 per sq ft (slower to install than wood)

All-in, a composite deck with composite or aluminium railing typically lands at $48–$52 per sq ft. Over 25 years, the maintenance saving — roughly $300–$500 a year in stain, sealer, and replacement boards on a wood deck — often closes most of the gap.

Worked Example: A 16 ft × 20 ft Deck

Take a common size: a deck 16 ft deep by 20 ft wide, attached to the house along one 20 ft side, standing about 4 ft off the ground. Deck area is:

Area = 16 ft × 20 ft = 320 sq ft

Open perimeter needing railing = 16 + 20 + 16 = 52 lin ft. Six footings carry the beam line and the outer posts. Here is the full build-up, priced both ways.

Pressure-treated pine version

• Decking boards: 320 sq ft × $4.50 = $1,440
• Framing lumber: 320 sq ft × $3.00 = $960
• Footings: 6 × $180 = $1,080
• Fasteners and hardware: 320 sq ft × $1.00 = $320
• Labour: 320 sq ft × $11.00 = $3,520
• Wood railing: 52 lin ft × $35 = $1,820
• One flight of stairs: $650
• Permit and inspection: $350

Total: $10,140, or $31.69 per sq ft. The bare deck structure alone (boards, framing, footings, fasteners, labour) is $7,320, or $22.88 per sq ft — right inside the $15–$25 band quoted at the top. Railing, stairs, and the permit add the remaining $2,820.

Composite version (same size, same layout)

• Composite decking boards: 320 sq ft × $14.00 = $4,480
• Framing lumber: 320 sq ft × $3.00 = $960
• Footings: 6 × $180 = $1,080
• Hidden fasteners and clips: 320 sq ft × $2.00 = $640
• Labour: 320 sq ft × $13.00 = $4,160
• Composite railing: 52 lin ft × $65 = $3,380
• One flight of stairs: $950
• Permit and inspection: $350

Total: $16,000, or $50.00 per sq ft. The composite deck costs $5,860 more than the pressure-treated version — about 58% more — and almost all of that difference sits in the boards and the railing, not in the structure underneath.

How to use these numbers on your own deck

The quick formula is: Total cost = (deck area × rate per sq ft) + (railing length × rate per lin ft) + stairs + permit. Measure your deck area, pick your board rate from the ranges above, add railing at $35 per lin ft for wood or $65 for composite, and you will be within 10% of a real contractor quote for a straightforward rectangular deck.

Extra Costs People Forget to Budget

• Old deck demolition: $500–$1,500 to tear out and haul away an existing deck, depending on size and whether the footings are reused.
• Ledger flashing: $200–$400 for proper metal flashing where the deck meets the house. This is the detail that prevents rot in the house wall — never let a contractor skip it.
• Lighting: $40–$80 per post-cap or stair light, plus wiring.
• Skirting or lattice: $8–$15 per lin ft to close in the space under a raised deck.
• Stain and sealer (wood only): $300–$600 for the first coat, then every 1–2 years.
• Upgraded footings: helical piles run $300–$500 each where soil is poor or frost depth is extreme.

How to Keep the Cost Down Without Cutting Corners

First, keep the shape rectangular. Every angle, curve, or bump-out adds cutting time and waste — a simple rectangle can save 10–15% against an L-shape of the same area. Second, match the deck height to the door: a low deck needs less railing and shorter stairs. Third, choose your board honestly: if you will genuinely re-stain every two years, pressure-treated pine is excellent value; if you know you will not, the composite premium pays for itself. Fourth, get three itemised quotes and compare them line by line — a quote that is $3,000 cheaper because it omits the permit and the flashing is not cheaper at all. And finally, build in the off-season if your climate allows it: late autumn and winter bookings often come in 5–10% lower than spring.

Frequently Asked Questions

How much does a 12 ft × 12 ft deck cost?

A 144 sq ft deck runs roughly $4,500–$5,500 in pressure-treated pine or $7,000–$8,500 in composite for the structure, plus $1,500–$3,000 for railing and stairs. Small decks cost more per square foot because the fixed costs — permit, mobilisation, stairs — are spread over fewer square feet.

Is composite decking worth the extra cost?

Usually yes if you plan to stay in the house more than 10 years. Composite costs about 50–60% more up front, but a wood deck needs roughly $300–$500 a year in staining and board replacement, while composite needs a wash with soap and water. Over 25 years the lifetime costs are close, and composite holds its appearance far better.

Can I build a deck myself to save money?

DIY saves the labour line — roughly $10–$13 per sq ft — so a 320 sq ft pressure-treated deck drops from about $10,140 to around $6,600 in materials and permit. But footing depth, ledger attachment, and joist spans are structural work: if you are not confident reading span tables and the local code, hire the framing out and do the decking boards yourself.

Do I need a permit for a deck?

In most US jurisdictions, yes — for any deck attached to the house, or any freestanding deck more than 30 in. above grade. Expect $150–$500. A deck built without a required permit can block a future house sale and may have to be torn out.

How long does a wood deck last?

A well-maintained pressure-treated pine deck lasts 15–20 years; cedar 20–25 years; composite and PVC 25–30 years or more. The frame usually outlasts the boards — many owners re-deck the same frame once, which is another reason to build the structure properly the first time.