“How much does a deck cost?” has two very different answers: what a contractor will charge you, and what the lumber costs if you build it yourself. This guide walks through both, using published 2026 cost guides and a line-by-line materials list for a real deck size.
What a new deck costs in 2026
HomeGuide puts the cost of building a new deck at $25 to $50 per square foot, and Angi at $30 to $60. Angi's average project comes to $8,318, with most homeowners paying between $4,339 and $12,651. For the popular 12 × 16 ft size, HomeGuide lists $4,800–$9,600 installed.
The material you choose moves the price more than anything else. HomeGuide's installed ranges per square foot:
| Material | Installed, per sq ft |
|---|---|
| Pressure-treated pine | $25–$50 |
| Cedar | $30–$47 |
| Redwood | $28–$54 |
| Composite | $40–$80 |
| Trex composite | $45–$70 |
| Ipe | $50–$70 |
| Aluminum | $100–$125 |
Where the money goes: labor vs materials
Labor is the biggest single line. HomeGuide estimates $11–$22 per square foot for labor and Angi $15–$35, and Angi says labor makes up 50%–70% of the cost of a pressure-treated deck. That is the share you keep if you build it yourself — along with the risk, the tool rental and several weekends of work.
On the materials side, the guides measure different things, which is why their numbers look far apart. HomeGuide's $14–$28 per square foot for a pressure-treated deck covers the whole structure. Angi's $2–$5 per square foot for pressure-treated “decking material” is the deck boards alone, and its composite boards run $12–$22.
A real DIY materials list: 16 × 12 ft pressure-treated deck
To see what the lumber yard bill looks like, we ran a 16 ft wide, 12 ft deep attached deck through our deck calculator: 5/4×6 boards parallel to the house with 1/8 in gaps, joists 16 in on center, a doubled 2×10 beam on 6×6 posts, 16½ × 24 in footings, and 5% extra boards. Prices are median shelf prices collected in September 2026.
| Item | Qty | Unit price | Cost |
|---|---|---|---|
| 16 ft pressure-treated 5/4×6 deck boards | 28 | $17.73 | $496 |
| 2×10 × 12 ft joists | 13 | $26.18 | $340 |
| 2×10 × 16 ft (ledger, rim, beam) | 4 | $35.88 | $144 |
| 6×6 × 8 ft posts | 4 | $35.38 | $142 |
| Joist hangers | 13 | $2.83 | $37 |
| 80 lb bags of concrete (footings) | 22 | $7.13 | $157 |
| 5 lb boxes of deck screws | 2 | $45.96 | $92 |
| Total | $1,407 |
That comes to $1,407, or about $7.33 per square foot; at the lowest and highest shelf prices we saw, $1,258–$1,611. The same deck with composite boards and composite screws is $1,841.
Notice this is well under HomeGuide's $14–$28 per square foot for DIY materials. The difference is everything the platform alone doesn't include: railings, stairs, ledger flashing and structural screws or bolts, post bases and beam hardware, hanger nails, stain or sealer, and tool or auger rental. Budget for those before comparing your number to a contractor's quote.
How size changes the price
Cost doesn't scale perfectly with area. HomeGuide's installed totals run from $2,500–$5,000 for a 10 × 10 ft deck to $10,000–$20,000 for 20 × 20 ft. Deeper decks need bigger joists or an extra beam, and wider ones need more posts and footings, so the structure grows in steps rather than smoothly. In our calculator, the same pressure-treated design costs $1,039 in materials at 10 × 10 ft and $1,407 at 16 × 12 ft; stretching the depth from 12 to 16 ft pushes the joists to 12 in spacing, and the materials for a 20 × 16 ft deck jump to $3,018.
Wood or composite: paying now vs later
Composite boards cost more up front. HomeGuide lists composite decks at $40–$80 per square foot installed against $25–$50 for pressure-treated pine, and the boards alone run $5–$15 per sq ft for Trex, $6–$13 for TimberTech/AZEK and $7–$14 for Fiberon. What you buy with that premium is mainly lower upkeep: composite boards aren't stained or sealed the way a wood deck is. The framing underneath is usually pressure-treated lumber either way, so the difference sits almost entirely in the boards, the hidden or color-matched fasteners and, often, closer joist spacing — Trex requires 12 in on center for diagonal boards.
Permits and code requirements
Most attached decks need a building permit. HomeGuide lists permits at $50–$150 and Angi at $230–$500, depending on where you live. The permit brings inspections, which is a good thing on a structure people stand on several feet off the ground.
Codes also set the parts that are easiest to get wrong. The American Wood Council's DCA 6 deck guide, which many building departments use, requires footings to bear at least 12 inches below undisturbed ground or below the frost line, whichever is deeper, sets a minimum post size of 6×6, and gives maximum spans for every joist and beam size. Our calculator follows those span tables, but your building department has the final say.
DIY or hire? A practical way to decide
- DIY tends to make sense for a low, simple rectangular deck close to the ground, when you already own a miter saw and drill and have help for lifting beams.
- Hiring tends to make sense for second-story or high decks, decks with stairs and complex railings, poor soil or deep frost lines, or anywhere the ledger attaches to a house with siding you'd rather not open up yourself.
- Either way, price the materials first. Knowing the lumber bill makes contractor quotes much easier to judge: if a quote is five times the materials, ask what's included.
Getting an accurate number for your deck
- Measure the width along the house, the depth out from the house and the height above the ground.
- Run those through the deck calculator for a materials list, and change the unit prices to what your local store charges.
- Add railings, stairs, hardware, finish and permit fees.
- Get at least two or three written contractor quotes that list materials and labor separately, and compare them against the deck cost tables.
Deck framing is structural: check local building codes before you build.
Sources
- HomeGuide — Cost to build a deck accessed 2026-09-17 · page dated 2026-02-10
- Angi — How much does it cost to build a deck? accessed 2026-09-17 · page dated 2026-08-03
- Angi — Pressure-treated decking cost accessed 2026-09-17 · page dated 2026-07-09
- HomeGuide — Composite decking prices accessed 2026-09-17 · page dated 2026-02-10
- American Wood Council — DCA 6: Prescriptive Residential Wood Deck Construction Guide (2015) accessed 2026-09-16
- The Home Depot — Pressure-treated deck boards accessed 2026-09-16
- The Home Depot — Pressure-treated 2 in. x 10 in. accessed 2026-09-16
- The Home Depot — Pressure-treated lumber, 12 ft accessed 2026-09-16
- The Home Depot — Pressure-treated 6 in. posts accessed 2026-09-16
- The Home Depot — Simpson Strong-Tie 2x8 joist hangers accessed 2026-09-16
- The Home Depot — #10 x 3 in. deck screws accessed 2026-09-16
- The Home Depot — Concrete Mix category listing accessed 2026-09-16
- Trex — How many deck boards do I need? accessed 2026-09-16
- Trex Academy — How to install deck joists accessed 2026-09-16
This guide explains how estimates are worked out; it is not a substitute for the product's instructions, local building codes or a qualified professional. Estimates for planning purposes only, not professional construction advice. Check local building codes and your product's instructions before you build. Prices are national averages collected from public retail listings and cost guides and will differ in your area. BuildHowMuch is independent and not affiliated with, endorsed by or paid by any retailer or manufacturer mentioned on this page. Nothing you enter is stored or sent anywhere.