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By Anna Turner, Nov 30 2016 09:17AM

How much does it cost to build a deck? There are many components, and variables influencing those components, that make up a deck. This article guides you through those components, to help you arrive at the answer yourself.


First we must assess how the deck should be built. Site conditions will determine the best method, and advice from an engineer is appropriate at this point. Decks may be built on a frame secured to an already solid base, such as a concrete slab, or they are (usually) secured to post that might be concreted or fixed to the ground in some way.

Here are a few websites that may help you with the assessment process:

The Australian Timber Database, , especially their PDF “Domestic Deck Design Guide”,, which takes you the different decking frame and footing options in clear detail.

Decks By Design,, has a great PDF called “How to build a deck”

Referring to the Australian Standards (AS1684) Residential Timber Framed Construction is always advisable.


Once you have reached the conclusion of how you are going to build the deck you are ready to price it.

After assessing our fictional site we have arrived at the conclusion that our 20m2 deck, sitting 350mm above ground, will be built as follows:

90x90m H4 Treated Pine posts, at 1.5m centres, concreted 450mm into the ground.

150x50mm H4 Treated Pine joists and bearers, with joist at 500mm centres and bearers at 1.5m centres.

19x130mm Blackbutt decking boards, with 4mm spacings, fixed with galvanised decking screws.

The best way to work out the price of any item is to build it in your head, and price each step as you go. I find it best to list all materials required, in order of use, followed by all Labour requirements in order of task. (NOTE: this table has been extracted from the LiberRATE program & converted to a table for this article).

Decking board formula: Quantity Required (in Lineal metres) = Area/(Board Width(

Exampe Quantity required (lm) = 20m2/.134 = 149.25lineal metres

The labour section of the table below shows all the tasks/steps that must be completed in order to build the deck. Breaking the steps down like this allows you to clearly think the process through, and assign a considered amount of labour to it.


90X90 Treated Pine H4 - 24.00lm = $456.00

Coach Bolts - 106.00each =$482.30

150x50 Treated Pine H4 - 69.00lm = $320.85

19X130 Blackbutt decking - 157.00**lm = $2,094.38

Decking screws 50x10G 1,000 box - 0.75 box = $69.55

Timber delivery - 1.00 each = $80.00

Concrete mix - Pre mix 10mm - 1.00Tonnes = $63.64

Concrete mix Delivery - 1.00each = $55.00

Total Materials = $3,621.72*


Carry materials in - 2p x 1.5hrs = $105.00

Set out - 2p x 4hrs = $280.00

Dig post holes - 2p x 4hrs = $280.00

Set posts in ground - 2p x 8hrs = $560.00

Bearers and joists in - 2p x 8hrs = $560.00

Install decking boards - 2p x 36hrs = $2,520.00

Clean up - 1p x 1hrs = $35.00

Total Man Days: 15.50 = $4,340.00*

Item Total = $7,961.72*

Rate per square metre = $398.09*

*NOTE: The example above is a GUIDE ONLY and not meant to be used to price work; each site will need to be assessed on its own merits. All prices listed are an example only, and are not intended to be used for pricing.

**NOTE: Quantity includes 5% wastage.

Once you have worked out what it will COST to build the deck, you must add PROFIT and OVERHEADS to that price to arrive at the SELL PRICE. Until you add Overheads the true cost to build the deck is unknown, and there is no point working for free so Profit is just as important.

I hope you have found this article helpful? Please leave me a message with feedback and/ or suggestions of what else you would like me to breakdown the pricing on. Thanks for your support!

Cheers, Anna Turner.

*Image by Outside Space Landscapes,

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