How much does a deck cost

Why the national average is useless

Every page that answers this question opens with a cost per square foot. It is the wrong shape of answer, for three reasons.

The spread is wider than the average is useful. The same deck, same plan, same crew, built in treated pine at ground level and in hardwood at second-storey height, are not two points either side of a mean — they are different projects.

Labour is local and volatile. Contractor rates vary by metro more than most materials do, and both move faster than any article gets updated.

Square footage hides the expensive parts. Stairs, guards, height and access are where the money goes and none of them scale with area. Two 300-square-foot decks can differ by a factor of three.

So this page does not give you a number. It gives you the structure of one, and a tool that turns your own quotes into a total.

What actually moves the number

Notice how many of these are decisions rather than conditions. Dropping a deck to ground level, squaring off a bay, or moving the stairs to the shortest drop can each take a large bite out of the total without changing the deck you actually use.

Building your own number

1. 01Settle the frame. Joist size and spacing, beam, post count. Guessing the frame guesses a third of the material.
2. 02Take off the quantities. Joists, beam plies, posts, decking boards, fasteners, concrete, hardware. The board and concrete tools do this arithmetic.
3. 03Get real unit prices. Call or check your lumber yard for each line. Twenty minutes here beats any published average, and the numbers are yours.
4. 04Add waste. Cutting loss on the decking, extra on any diagonal or picture-frame layout, and a couple of spare boards you will be glad of.
5. 05Add the non-lumber lines. Permit fee, concrete, hardware, disposal, delivery, equipment hire, and the stain if it is going on now.
6. 06Add labour, or add your weekends. If you are hiring, this is the biggest single line. If you are not, price it anyway so you know what your time is buying.

The deck cost calculator runs this in one place: you supply the unit prices, it supplies the quantities and the arithmetic. Nothing in it is a national average, because there is no useful one to give.

The labour question

Labour is normally the largest line on a contracted deck, and it is not one rate. It covers layout, digging, concrete, framing, decking, guards, stairs, clean-up, and the time spent waiting for inspections. It scales with complexity far more than with area.

Rates are local and move, so the honest instruction is the same as for material: get real numbers from real contractors in your market. A pricing article cannot know what a crew in your county charges this month.

Building it yourself does not remove the labour, it moves it onto your weekends, and it does not remove the tools, the disposal, the delivery or the permit. Price the full job before deciding, then subtract the labour to see what you are actually saving.

Reading three quotes

Get three, and read the scope before the price. Quotes that look far apart are usually describing different decks.

Check that each one names the decking product and grade, the framing species and size, the footing depth and diameter, the guard system, whether stairs and the landing are included, whether the permit and its fee are the contractor's job, whether demolition and disposal of the old deck are in, and what the payment schedule is.

A quote that is one line and a number is not cheaper, it is unspecified — and every unspecified item becomes a change order at the contractor's convenience. The bid template is the shape a good one takes; if you are the contractor, printing that is the fastest way to look like the serious quote in the pile.