Home › Deck

Deck cost

Deck cost calculator

Estimate the cost to build or replace a deck: square footage and board material, height, railing, stairs, demolition and permits, with a check on what insurance would pay after a covered loss.

Reviewed 8 October 2026

See the illustrated guide

Written and maintained byMantu Kumar

Evidence review8 October 2026

Calculation rulesRead the methodology Quality standardEditorial policy

Key facts at a glance

Professionally built decks run about $30–$60 per sq ft all-in.
300 sq ft pressure-treated: $4,500–$7,500 installed.
300 sq ft composite: $9,000–$18,000 installed.
Railing $20–$80 per foot; stairs $50–$150 per step.
Permits usually cost $50–$500.
Building it yourself saves about 50%–60%, paying for materials only.

Sources: RemodelAI and NerdWallet, listed at the end of this page.

Deck building cost estimate

No email · nothing sent

On the deck itself

See the boards, the house connection and the height off the ground

The photograph is taken from the deck, so the surface, the wall it meets and the stairs down to the yard are all visible.

Wood deck attached to a house, with deck boards, a railing, stairs and the framing visible above the yard. — Boards, railing, the house wall and the stairs. Those four things drive most of a deck estimate.AI-generated illustration for explanation. Not a site inspection, measurement or eligibility record.

The three detail views below enlarge parts of the same photograph. Use them with the checks underneath.

Deck boards, railing and the edge where the framing shows.

Deck boards and railing

Measure the deck surface

Multiply length by width for the area. Measure the open sides separately for railing, and count the steps down to the yard.

Deck boards meeting the house wall beside a sliding door.

Where the deck meets the house

Check the ledger and flashing

An attached deck hangs on a ledger fastened to the house. Ask how it is bolted and flashed. That joint is the detail that fails first if water gets behind the siding.

Deck stairs and the open framing above the yard.

Stairs and height off the ground

Plan the footings and the steps

Height above grade sets post size, bracing, railing and how many steps you need. A slope often means taller posts at one end.

Before you sign a deck quote, confirm these

Structure: Footing size and depth, joist size and spacing, and how the ledger is attached and flashed
Surface: Decking material, fasteners and the board warranty
Safety: Railing height, baluster spacing, stair rise and run, and the permit and inspections

Price a fence around the yard

Deck cost per square foot by material

Installed deck platform 2 to 8 ft above grade, before railing, stairs and permits. Source: RemodelAI 2026 deck cost guide.
Decking	Installed per sq ft	Typical life
Pressure-treated pine	$15 – $25	10 to 20 years
Cedar	$25 – $35	15 to 20 years
Redwood	$30 – $45	15 to 25 years
Composite	$30 – $60	25 to 30 years or more
PVC	$35 – $60	30 years or more
Ipe hardwood	$35 – $60	40 years or more

The framing under almost every deck is pressure-treated lumber, so the board material changes the surface cost, the upkeep and the life more than the structure. Composite and PVC cost more at the start and need no staining.

Railing, stairs and height

Railing is required on most decks more than 30 inches above the ground and runs from about $20 per foot in wood to $80 or more in aluminum, and more again for cable or glass. Stairs cost roughly $50 to $150 per step. A second-story deck needs taller posts, bracing and staging, so it costs noticeably more per square foot than one close to the ground.

Permits, footings and the ledger

Permit. Most towns require one for decks attached to the house or more than about 30 in. high. Expect drawings and inspections.
Footings. Posts sit on concrete footings sized for the load and set below the frost line.
Ledger. An attached deck hangs on a ledger board bolted to the house and flashed against water. A failed ledger is the most common cause of deck collapse.

Repair, resurface or rebuild

If the framing is sound, new boards and railing on the old structure can save a third or more. Probe joists, posts and the ledger with a screwdriver; soft wood, rusted fasteners or a missing ledger flashing mean the frame should be rebuilt before new decking goes on. The repair or replace calculator explains the general rules of thumb.

What insurance covers

Attached decks are part of the dwelling; free-standing ones are other structures. Storm, fire and tree damage are usually covered, rot and wear are not. If someone is injured on a failing deck, the liability part of the policy responds, which is a strong reason to fix a loose railing promptly.

Questions

How much does it cost to build a deck per square foot?

Installed decks commonly run about $15 to $25 per sq ft in pressure-treated pine and $30 to $60 in composite or PVC, before railing and stairs. All-in, professionally built decks often land between $30 and $60 per sq ft.

How much does a 300 sq ft deck cost?

In pressure-treated pine, 2 to 8 ft high, with 40 ft of wood railing and four steps, this calculator returns about $5,600 to $10,200 at the national average, including a permit allowance.

Is composite decking worth the extra cost?

Composite costs more to build but needs no staining or sealing and typically lasts 25 to 30 years or more, against 10 to 20 for pressure-treated wood. Over the life of the deck the gap narrows.

Do I need a permit to build a deck?

Usually, for decks attached to the house or more than about 30 inches above the ground. The permit brings plan review and inspections of footings, framing and the ledger.

Can I replace just the deck boards?

Yes, if the joists, beams, posts and ledger are sound. Resurfacing with new boards and railing often costs a third less than a full rebuild.

Does homeowners insurance cover a deck?

Attached decks are covered as part of the dwelling and detached ones as other structures, for covered causes such as fire, wind and falling trees. Rot, insects and wear are excluded.

How long does a deck last?

Pressure-treated wood decks often last 10 to 20 years, cedar and redwood 15 to 25, and composite or PVC 25 years or more with the framing kept dry.

Fence cost calculator — price a fence around the yard
Repair or replace calculator — rules of thumb for older items
Home rebuild cost calculator — decks count toward the dwelling limit
What insurance actually pays — dwelling and other structures

How to use this result This is a planning range from published per-square-foot prices and ReplaceCost’s assumptions, not a quote. Footings, framing, local code and the site change the real price. Get itemized quotes that list the framing and decking separately.

Evidence trail

Sources used to check this tool

Per-square-foot prices come from published deck cost guides; structural terms from the American Wood Council deck guide.

Reviewed 8 October 2026

Deck pricingRemodelAI: deck cost guide Deck pricingNerdWallet: cost to build a deck Deck constructionAmerican Wood Council DCA 6 deck guide CoverageInsurance Information Institute: what a homeowners policy covers

These organizations do not endorse ReplaceCost. The written policy, program rules, contractor scope and applicable law control the real result. See the full methodology for the source hierarchy and update process.

Deck planning

Price the platform, the railing and the stairs

Board material sets the surface cost; height, railing and stairs set the rest.

Cost per square foot Decking material sets the base rate.

Railing and stairs Priced by the foot and by the step.

Ledger and footings The structure decides safety and permit approval.

Coverage Attached decks are part of the dwelling.