Guide to Deck Costs: How Much Does Building a Deck Cost?

Guide to Deck Costs: How Much Does Building a Deck Cost?

Adding a deck to your back garden is a dream for many homeowners. A deck can turn a bland outdoor area into the perfect space for entertaining; the perfect place for lounging in the sun and BBQs. And, you’ll not only increase your home’s floor space but with the right deck, you can also increase the value of your home.

Installing a deck requires some planning. There are government regulations to be followed, and decisions to be made about the type, size and materials used in your deck. All of these factors will impact the overall cost.

So how much does building a deck cost? Here’s a breakdown of the cost of materials and installation which will give you a good idea of the final deck price.

The size and shape of your deck

When it comes to the cost of the deck, the size, the materials used and shape of the deck will be a significant factor in the final price.

Having a deck professionally built in Perth, Western Australia costs $200/m2 on average with a small deck between 10m2 – 20m2 costing around $4,000, a mid-size deck around $7,000 and a large deck 50m2+, costing on average $9,000.

Decks that have a unique shape, e.g., those with rounded edges or built around existing fixtures in the garden, will cost more than a standard squared deck.

How much does it cost to build a timber deck?

The cost of a timber deck varies depending on the type of wood used. You can expect to pay around $160/m2 for a basic treated pine decking and more than $280/m2 for an Australian hardwood timber decking.

It is important to note that timber decking requires ongoing maintenance as UV rays from the sun can fade and dry out the timber, causing it to warp, split and crack. Too much water in the timber will cause it to decay and allow fungal infection and rot to take over, as will too much dirt.

These issues can be fixed by staining your deck, applying a deck oil or painting it. This is something you will have to do every 12 – 24 months.

Even though a “cheaper” option such as pine timber may look like the way to go, it can require costly maintenance, as opposed to a wood, like Merbau (which is a lot harder wearing and just as sustainable). So, keep this in mind when deciding on what material you think is best.

How much does it cost to build a composite deck?

Guide to Deck Costs: How Much Does Building a Deck Cost?

Composite decking provides a great value proposition, especially in the long-term, as after installation, composite decks don’t need expensive upkeep in the same way timber decks do.

Composite decks are made from a combination of recycled timber fibres and plastic. This material is durable and waterproof making it an excellent choice for decking.

The average cost to install a basic composite deck starts at $170/m2 and goes up to $350/m2 or more, depending on the brand. Some of the most popular brands include Trex decking, NewTechWood, Timbertech, Modwood, and Millboard, each with a different price point and features.

Trex decking is widely considered one of the best composite decking materials in the world. Highly resistant to mould, scratching, fading and staining, the higher initial cost is quickly offset by the reduced maintenance costs over its 25-year guaranteed life.

Accessories, extras and “hidden” costs

Guide to Deck Costs: How Much Does Building a Deck Cost?

Decking not only comes in different shapes, sizes and materials but can also be made unique to your style.

Raised or sloped decking can add considerable costs to your deck. A raised deck will also need to be fenced and have stairs leading to the garden.

You may also need to account for additional labour costs. These can increase by having a garden that is hard to access with specialist equipment, issues with services such as gas or water lines or the need for scaffolding.


When you’re in the market for a deck, the cost involved can vary significantly. However, a standard small-sized composite deck will start around $4,000 from planning to installation. While a large, roofed deck made from the highest quality hardwood timber could set you back as much as $25,000.

It all comes down to what you want. If you are in the market for a deck in Perth contact Austim today. We can help you pick the best material for your deck, at the most competitive prices and put you in touch with specialist deck builders to get you the deck you desire.

Want to learn more about decking and the costs involved? Check out these resources from our decking experts:

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What our clients say

Austim are a great partner and timber supplier. Our business is based on the East Coast of Australia and we partner with Austim for WA projects. We have had a long lasting and great working relationship with Austim for many years. Highly recommend them.
daniel wright
daniel wright
06:31 18 Jun 19
Austim is always the first place I try when I need timber and it’s rare that I can’t get what I need there. Stuart is a rare gem of a gent to deal with – quick to respond to any queries, full of good advice and goes out of his way to help get whatever project I’m working on happening to my schedule, even when all I need is a few sticks and a handful of fixings. Highly recommend Austim, the team and young Stuart.
Anni Lilford
Anni Lilford
00:51 16 Nov 18
Stuart went out of his way to make sure we got the product we wanted. He made suggestions on possible constructions and timbers suitable. Very knowledgeable friendly staff all around. Excellent experience, highly recommended.
Holger Butenschon
Holger Butenschon
05:14 22 May 18
Hi Ben,Just wanted to thankyou for your help and advice in our selection of the Millboard Vintage Oak decking also in you recommending Grant from Premier Hardwood Decking. Grant has just completed our decking and we couldn't have asked for a more professional, reliable and competent tradesman. The decking has been installed to a very high standard and the decking itself is stunning. Ian and Sue
susan smith
susan smith
06:27 08 Oct 18
I've used Austim on a few occasions for home projects like decking and pergola, etc and each time the response to my requests for price and delivery have been excellent, the deliveries took place as negotiated, the timber quality was great and value for money. The team at Austim do a great job and make dealing with Austim a breeze.
Michael Robinson
Michael Robinson
09:06 25 Oct 18
I have worked with Austim for around 8 years now and they are one of the best suppliers in perth to deal with. I would highly recommend to use them for any timber needs!!!
Art of Timber
Art of Timber
07:55 05 Mar 20
I had been looking for some cedar for my kayak project and had rung a couple of other places with no luck. When I contacted Austim they were very helpful, had the timber in stock and I was on my was in 20 minutes. The wood was very good quality and has really finished up beautifully. Thanks to Austim.
mark alderson
mark alderson
02:03 08 Apr 17
I"d like to thank Austim for there help in supplying me with material that firstly I thought I'd have trouble sourcing as it was marring up with originally 30 year old existing timber.My project was not a massive project but still needed the attention of an new build.The timber supplied by Austim was machined to size with absolute perfection, where I had to remove old pieces and replace with the new pieces they fitted perfectly.once the floors are re-sanded and varnished they will be back to there former glory. Thanks again to the staff at Austim.Regards Bob Heppenstall.I've just added a finished photo after the Floor Sanding was completed.Original timber was Tassie Oak, and the new is Vic Ash, as you can see there is only a slight variation in the final product.I hope this gives anyone thinking doing the same the confidence to proceed. Regards Bob Heppenstall.
Robert Heppenstall
Robert Heppenstall
10:05 12 Oct 18
Great service over phone and by email. Product supplied is high quality - no issues. Staff accommodating and friendly.
00:18 07 May 20
Good service with fair prices.
Colin Della Bosca
Colin Della Bosca
08:14 04 Jun 20

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