How much does it cost to build a deck in Australia?

Decking is one of the most requested outdoor carpentry jobs in Australia, and it is also one of the trickiest to price from a distance, because the final figure depends heavily on the material you choose long before anything else — size, height and finish — comes into play. Getting a rough sense of where the main materials sit price-wise makes it much easier to set a realistic budget before you start collecting quotes of your own.

Treated pine is generally the cheapest decking material and a common starting point for budget-conscious projects, with installed pricing commonly landing somewhere between $200 and $280 per square metre. It is widely available, straightforward to work with, and a reasonable choice if upfront cost is the main priority, though it typically needs more frequent maintenance over its life than the hardwood or composite options below. Hardwood species — merbau, spotted gum and ironbark are the ones most commonly used for decking in Australia — sit higher, with installed pricing commonly ranging from around $280 to $420 per square metre depending on species and grade; merbau specifically is often quoted around $300 to $350 per square metre, making it one of the more popular mid-to-premium choices.

Composite decking, made from engineered wood-fibre and plastic rather than solid timber, commonly costs somewhere between $350 and $550 per square metre installed for good-quality boards, though some entry-level hollow-core composite products can start lower, roughly $250 to $350 per square metre. Composite generally costs more upfront than timber, but it is engineered specifically to reduce the ongoing maintenance that timber decking requires — our separate article comparing timber and composite decking in more depth covers that trade-off, including lifespan and upkeep, if you are still deciding between the two.

The figures above are typically all-in installed prices, but where a quote is broken down separately, professional installation labour alone commonly runs somewhere between $50 and $120 per square metre, on top of the material cost. A handful of other factors move the total meaningfully beyond material choice alone. An elevated deck costs more than a low, ground-level one, since it needs a more substantial substructure, footings and often engineering sign-off; decks above a certain height commonly require handrails or balustrades under building regulations, which adds to both the material and labour cost. Stairs, difficult site access, extensive ground preparation, and whether the project needs council approval — more likely for larger or elevated decks — can each add a meaningful amount on top of a straightforward per-square-metre estimate.

It is also worth understanding when a licensed builder or carpenter with the right registration is legally required for the job, since deck-building can trigger state licensing thresholds depending on the value and type of work involved — our separate article on carpentry and deck-building licensing rules explains how that works state by state.

None of the figures above are a quote for your own project, and actual pricing depends on your location, the carpenter you use, and the specifics of your site. This article is general information, not a substitute for a written quote. Getting two or three quotes from carpenters who have actually seen your site is the most reliable way to know what your deck will cost — our directory lists Australian carpenters and deck builders by area if you are ready to start comparing.

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