How much does decking cost in Australia? (2026 guide)

A new deck is one of the highest-return outdoor projects you can do in Australia, but "how much does decking cost?" almost never has a single answer. The honest version is a range: roughly $200 to $1,000 per square metre installed, depending mostly on the board material, the height of the deck, and how hard your site is to work on.

This guide breaks down where in that range your deck is likely to land, what actually drives the cost, and a worked example so you can sanity-check any quote you receive. Figures are 2026 estimates for residential work and include both materials and professional installation, GST inclusive.

Decking cost per m² by material

The single biggest lever on price is the board itself. Here are realistic 2026 installed rates, drawn from current Australian cost guides and supplier pricing.

| Material | Installed cost (per m²) | Best for | | --- | --- | --- | | Treated pine | $200-$350 | Budget builds, painted or stained decks | | Hardwood (merbau, spotted gum, blackbutt) | $300-$550 | Classic timber look, durability | | Composite (Trex, Modwood, ekodeck) | $280-$650 | Low maintenance, modern finish | | Premium / capped composite + features | $650-$1,000+ | Raised decks, curves, integrated lighting |

These figures align with 2026 industry guides putting decking broadly in the $200-$700/m² range for standard work, with premium and complex builds pushing past $1,000/m² (Yellow Pages, Brite Decking, Hosung).

What actually drives the price

The board is only part of the story. Four things move your quote up or down:

• The substructure. Posts, bearers and joists are hidden but they're real money. Ground-level decks need very little; raised decks need taller posts, deeper footings and more bracing. A heavier hardwood deck also needs a stronger frame than a lightweight composite one.
• Height and balustrade. Once a deck is around a metre off the ground you usually need a compliant balustrade and, in most cases, council approval, and both add cost. Balustrade alone (timber, steel, glass) can add $150-$400+ per linear metre.
• Fixings and finish. Face-fixed screws are cheapest. Hidden-fixing clip systems give a clean board face but cost more per m² and add roughly 15% to labour because they're slower. Timber also needs oiling/staining; composite doesn't.
• Site access and ground conditions. A flat, open backyard is quick. Sloping blocks, rock, poor soil, or a deck you can only reach by carrying everything through the house all add labour hours.

A worked example

Say you want a 24 m² merbau deck (4 m × 6 m), ground level, in a Sydney suburb with easy access.

| Line item | Estimate | | --- | --- | | Merbau boards (86×19, ~7% offcut buffer) | $4,300 | | Substructure (posts, bearers, joists) | $1,900 | | Fixings + 2 coats decking oil | $700 | | Labour (~16 hours, 2-person crew) | $2,600 | | Total (inc GST) | ≈ $9,500 |

That works out to about $395/m², squarely in the hardwood band. Swap merbau for treated pine and you'd save roughly $2,000-$2,500; step up to capped composite with a picture-frame border and you'd add a similar amount. Raise the same deck 1.2 m off the ground with a balustrade and you could add $3,000-$5,000 for the taller frame and railing.

How prices vary across Australia

Where you live moves the number too. Sydney and Melbourne sit at the top for labour, Brisbane and Perth a touch lower, and Adelaide and many regional areas cheaper again, though regional jobs can swing back up if materials have to be freighted a long way or tradies are thin on the ground. As a rough rule, the same deck can vary 10-15% in price between the cheapest and dearest metro markets, almost entirely on the labour line. Coastal builds also tend to cost more because exposed decks need more durable, more expensive timber or capped composite to survive salt and UV.

Don't read too much into a single per-m² figure you saw online for another city. A flat Adelaide backyard and a steep, access-restricted Sydney harbourside block can carry the same area and the same boards yet differ by thousands, which is exactly why a tailored quote beats an average.

How to keep the cost sensible

• Match the material to how you'll use it. If you'll never oil a deck, don't buy hardwood. You'll watch it go grey. Composite or a painted pine deck is a better fit.
• Keep it low if you can. Staying under the height that triggers a balustrade and council approval saves real money.
• Get the spec right before you quote. Most quote blow-outs come from changing the board, adding stairs, or discovering the ground isn't level. Nail the scope first.

Questions worth asking before you commit

• Is the quote fixed price or an estimate? A fixed price protects you from surprises; an hourly estimate can drift.
• What's the substructure made of, and is it included? Cheap quotes sometimes assume an existing frame or skimp on footings.
• Who handles council approval if the deck needs it? Clarify whether the builder lodges it or you do.
• What's the warranty on workmanship, and what does the board manufacturer warrant? Composite often carries a long material warranty; the install is separate.
• How is timber finished and maintained? If it's hardwood, you'll be oiling it, so factor that ongoing cost in.

A deck is a 15-to-25-year asset. The cheapest quote that cuts the frame or skips the finish is rarely the cheapest deck once you count the repairs.

Get a tailored number

Every deck is different, and a per-m² average can't see your block, your access or the board you want. Rather than guessing, enter your dimensions and spec into Karven's decking calculator and get an itemised, fixed-price quote in minutes.