Why a deck price per square foot swings from $22 to $88
Deck builders quote the whole deck, but customers compare by the square foot, and the per sq ft number changes with what is included. Use it to sanity-check a quote after you build it, never to build one.
| A | B | |
|---|---|---|
| 1 | What the number includes | Per sq ft |
| 2 | Framing materials only, from a decking brand's estimate | About $5 |
| 3 | Materials only for a 12 x 20 low deck, premium PVC boards, no rail or steps | $21.71 |
| 4 | Full price for a 13 x 36 deck: PVC decking, aluminum rail, PVC wrap, no steps | About $77 |
| 5 | Full price for the sample 12 x 20: composite, 3-step stair, aluminum rail | $87.75 |
The two full prices sit close together even though the 13 x 36 deck used pricier boards on a bigger footprint. The sample carries stairs, a stair rail and a pad on a smaller deck, and fixed costs like the permit and inspection trips weigh more on 240 sq ft than on 468. See quote vs estimate for what to call the number you send.
What a 12 x 20 composite deck with stairs and railing comes to
The sample deck costs $15,106.28 to build and sells for $21,060.88 once markup, a small cushion and 25% profit go on. It is attached to the house, about 4 ft off the ground, with three footings under one beam, capped composite boards on hidden clips, fascia wrap on three sides and a picture-frame border.
| A | B | |
|---|---|---|
| 1 | Part of the price | Amount |
| 2 | Materials, with 10% waste | $7,992.60 |
| 3 | Labor, truck and tools | $5,360.32 |
| 4 | Permit | $350.00 |
| 5 | Off-deck hours and costs | $1,403.36 |
| 6 | Markups, cushion and profit | $5,954.60 |
| 7 | Price | $21,060.88 |
About 81 crew hours happen on site, from layout to the final walk-through, and the off-deck lines bring the total to about 99.5 labor hours. Each of those hours brings in $121.22 toward wages, overhead and profit, about double the crew's break-even.
Materials are only about 38% of this price. A quote built as lumber times two would land near $16,000 and leave most of the profit behind. Seen from the homeowner's side, the same fact explains why building it yourself can save half or more: most of the price is skilled hours, not boards.
Where the $61.37 crew rate comes from
Every billable hour of the sample crew has to bring in $61.37 before the truck, the auger or profit. That covers an owner and two crew with their payroll costs, and $40,900 a year of overhead for the yard, insurance, marketing and the rest.
The owner bills the fewest hours because he is the one selling, drawing plans and buying material, so his pay weighs heaviest on the rate. How that number is built, and what markup and profit sit on top, is on deck builder hourly rate. Put your own crew into the free true hourly rate calculator to get yours.
Railing and decking: the two lines that move a deck price most
On almost every deck, the boards and the railing are the biggest material lines, so they decide where the price lands. On one 12 x 20 low deck, $3,250 of a $5,212 material budget went on premium PVC boards. The decking alone can be the most expensive part of the project.
A bigger 13 x 36 deck had about $9,000 of decking with hidden clips and about $5,900 of black aluminum railing. Its builder says pressure-treated would have been 40 to 50% cheaper, but it needs staining and sealing every few years. Capped composite saves about $3 a lineal foot over premium PVC.
That is why the quote has to name the product line. Decking prices now vary widely from one line to the next, so a customer who switches after signing gets a new price, not the old one.
Inspection trips, the stair pad and other costs deck quotes miss
On the sample deck, the off-deck lines add $1,403.36, about 9% of cost and more than a third of the profit if they were left out. None of them is on a lumber list, which is exactly why they slip.
- Drawing plans and the permit application. The plans the building department wants take real hours. It is evening work, so it never feels billable.
- Return visits for every inspection. Footing, framing and final are three trips back to the site, and three short trips are not zero.
- Drive time and gas every day on site. Build them into the labor price, so a far-away deck and a close one don't cost the same.
- Lumber yard and supplier runs. The short load, the missing hangers, the return of what was over-ordered.
- Digging to the depth the town requires. Footings under the deck and under the stair base have to go below the frost line, which can be 32 inches or more in cold places. Rock and roots show up in the hole, not on the plan.
- Rain days. Weather is a cost many contractors never account for. A lost half day still costs a full crew.
- The pad at the bottom of the stairs. Steps mean more framing, more decking, more railing and a concrete or paver pad. The stair gets priced; the pad under it gets forgotten.
- Boards bought only for border cuts. Boards come in 12, 16 and 20 ft lengths, and a 33 ft run can't be spanned by any single factory board. Plan on about 10% waste, or closer to 5% with a carefully planned layout.
- Haul-away, scaffold over about 9 ft and warranty callbacks. A 5-year workmanship warranty is a selling point, and each trip back to fix a popped board is unpaid time.
Put your own hours on these by timing them on your next three decks. That habit is job costing.
Deck terms that stop free work: product swaps, rock in the holes, rain
Most unpaid deck work comes in through something the quote didn't say. The terms that matter most on a deck: anything not written in the quote is extra and gets priced on a signed change order before it is built; switching decking or railing after signing gets re-priced; rock, roots or buried lines found while digging are quoted separately; and rain or frozen ground moves the date, not the price.
Put one more in the scope itself. Old decks torn out with no flashing on the ledger board are a common sight, and any flat framing where water can sit should get joist tape. Put ledger flashing and joist tape in as their own lines, so they never get cut to hit a number. The calculator comes with ready-made deck terms that print on every customer quote.
Five ways deck quotes go wrong
Most deck pricing mistakes come from shortcuts, not bad math.
- Reusing a per sq ft number$21.71 a sq ft for materials only and $87.75 for a full deck with stairs and rail are both real, and one number can't cover both.
- Thin profitPlan on at least 25 to 35% profit. Plenty of builders admit they once made only about 10% and didn't know it until the year was over.
- Pricing stairs without the padOr railing by the foot when it is sold in 6 or 8 ft sections.
- No term on product swapsWhen decking prices vary as much as they do.
- Rounding the trips to zeroInspections, yard runs and daily driving add up to most of a working day on a typical deck.
The Deck Building Pricing Calculator does all of this on your own numbers, in Excel or Google Sheets: your crew rate, your lumber yard and supplier prices, the off-deck list and a customer quote with deck terms built in.