How Much Does It Cost to Build a Deck in 2026?

A deck is one of the few home improvements that consistently delivers strong ROI — the 2026 Cost vs. Value Report puts composite deck additions at 40–60% return and wood deck additions at 50–70% return. That said, costs vary significantly by material, size, and complexity. Here's exactly what to expect.

Deck Cost by Material (per Square Foot, Installed)

Decking Material	Material Cost	Total Installed	Lifespan	Maintenance
Pressure-treated pine	$2–$5/sq ft	$15–$25/sq ft	15–25 years	Seal/stain every 2–3 years
Cedar	$4–$8/sq ft	$18–$35/sq ft	15–25 years	Seal/stain every 2–3 years
Redwood	$5–$12/sq ft	$20–$40/sq ft	20–30 years	Occasional sealing
Composite (mid-grade)	$8–$18/sq ft	$25–$45/sq ft	25–30 years	Wash 1–2x per year, no sealing
Composite (premium)	$15–$30/sq ft	$35–$60/sq ft	30+ years	Minimal — wash occasionally
Tropical hardwood (Ipe)	$10–$20/sq ft	$30–$50/sq ft	40–75 years	Oil annually

Deck Cost by Size (Pressure-Treated, Professionally Installed)

Deck Size	Sq Ft	Low Estimate	High Estimate	Average
10 x 10 ft	100 sq ft	$1,500	$2,500	$2,000
12 x 12 ft	144 sq ft	$2,160	$3,600	$2,880
12 x 16 ft	192 sq ft	$2,880	$4,800	$3,840
16 x 16 ft	256 sq ft	$3,840	$6,400	$5,120
16 x 20 ft	320 sq ft	$4,800	$8,000	$6,400
20 x 20 ft	400 sq ft	$6,000	$10,000	$8,000
20 x 24 ft	480 sq ft	$7,200	$12,000	$9,600

For composite decking, multiply these figures by 1.5–2x. A 16x20 ft composite deck typically runs $8,000–$16,000 installed.

What's Included in Deck Cost

A professionally installed deck price should include footings and posts, beam and joist framing, decking boards, stairs (if applicable), railings, and permit fees. Get a detailed written quote that breaks each component out separately — this is the only way to compare contractors fairly.

Footings and framing (posts, beams, joists) typically account for 40–50% of total cost regardless of decking material. This is why the difference between pressure-treated and composite decking isn't as large as the per-square-foot material difference suggests — the structural cost is the same either way.

Railings are required by code for decks over 30 inches above grade and add $30–$60 per linear foot. A 16x20 deck with three open sides needs roughly 50 linear feet of railing — add $1,500–$3,000 to the base deck cost.

Stairs are quoted per step — typically $100–$300 per step installed. A standard 4-step stair set adds $400–$1,200.

Composite vs. Pressure-Treated: True Cost Comparison

The upfront cost difference between PT and composite is real — typically $10,000–$15,000 more for composite on a mid-size deck. But the lifetime cost comparison is closer:

Pressure-treated deck: stain or seal every 2–3 years at $300–$800 per treatment. Over 25 years: $2,500–$6,700 in maintenance. Boards may need replacement in 15–20 years.

Composite deck: wash 1–2 times per year (minimal cost). Most composite products carry 25–30 year warranties. Little to no maintenance cost over the same period.

Over 25 years, a PT deck and a composite deck often reach similar total cost — but the composite requires no weekend maintenance projects to get there.

DIY Deck Building

Labor accounts for roughly 50% of deck installation cost. A DIY 16x20 PT deck can cost $3,000–$5,000 in materials versus $8,000–$12,000 installed — savings of $5,000–$7,000. The project requires structural knowledge, ability to read permit drawings, and several weekends of work.

DIY deck building is feasible for homeowners comfortable with basic framing. The non-negotiables: getting the permit, calling 811 before digging footings, and having the footings and framing inspected before adding decking boards. Structural mistakes are dangerous and expensive to correct after the decking is down.

Frequently Asked Questions

How much does a 12x16 deck cost? A 12x16 ft (192 sq ft) pressure-treated deck costs $2,880–$4,800 professionally installed. The same deck in composite runs $4,800–$9,600. DIY material cost for PT lumber runs $1,200–$2,000.

Do I need a permit to build a deck? In virtually every US jurisdiction, yes. Decks require a building permit, structural drawings, and inspections at footings and framing stages. Permit fees run $150–$500. Unpermitted decks create problems at resale and with homeowner's insurance.

How long does it take to build a deck? A professional crew builds approximately 200–300 sq ft of decking per day. A 16x20 deck takes 3–5 days including footings, framing, decking, and railings. DIY construction of the same deck typically takes 2–4 weekends.

Is building a deck worth it? The 2026 Cost vs. Value Report shows wood deck additions returning approximately 50–70% of cost at resale. The true value is years of use before the sale — a deck that gets used regularly for 10 years before a sale delivers both use value and some resale value.