Decking Cost per Square Metre in Australia 2026 — Plus 15m² Deck Prices

Decking costs $200–$550 per square metre installed in Australia in 2026, which puts a standard 15m² deck (roughly 5 m × 3 m) at $3,000–$8,250 depending on the timber you choose. Treated pine sits at the bottom of that range; premium solid-core composite sits at the top.

Decking is one of the most popular outdoor upgrades Australian homeowners tackle each year — and it's one where the per-square-metre price can jump dramatically depending on the timber, how high the deck sits off the ground, and whether you need balustrades or stairs.

Treated pine at $200–$280/m² and premium composite at $450–$550/m² are both valid choices. They're just solving different problems. This guide breaks down exactly what you'll pay per m², what common deck sizes cost in total, why the price varies, and what to look for before you sign off on a quote.

Last updated: September 2026.

Key takeaways

• Decking costs $200–$550/m² installed in Australia in 2026, with material choice the single biggest driver of where you land in that range.
• A 15m² deck costs $3,000–$8,250 installed — $3,000–$4,200 in treated pine, $4,200–$5,700 in merbau, and $6,750–$8,250 in premium solid-core composite.
• Treated pine decking runs $200–$280/m² installed — the most affordable entry point for a solid, durable deck.
• Hardwood (merbau, spotted gum, ironbark) costs $280–$420/m² installed, depending on species and grade.
• Composite decking ranges from $350–$550/m² installed — hollow-core at the lower end, solid-core premium boards at the top.
• Elevation adds cost: a deck more than 500 mm above ground adds $50–$100/m² for the beefier sub-frame and engineering required — about $750–$1,500 extra on a 15m² deck.
• Balustrades and stairs are priced separately — budget $250–$600 per linear metre for balustrades and $1,500–$3,500 per flight of stairs.

Table of contents

1. What does decking cost per square metre in Australia?
2. How much does a 15m2 deck cost?
3. What does treated pine decking cost?
4. What does hardwood decking cost: merbau, spotted gum and ironbark?
5. Composite decking: hollow core vs solid core?
6. What else affects the price of a deck?
7. When does the sub-frame need replacing?
8. How do you get an accurate decking quote?
9. FAQs

What does decking cost per square metre in Australia?

Decking costs between $200 and $550 per square metre installed in Australia in 2026. Treated pine is the cheapest at $200–$280/m², hardwood sits at $280–$420/m², and composite runs $350–$550/m² depending on whether the board is hollow-core or solid-core.

These are installed rates — materials, labour, fixings and a standard ground-level sub-frame included. Prices are indicative estimates based on rates from Leadkit's decking quote calculator, which uses current Australian market data. Your tradie will confirm the final price after assessing your job.

These are price indications only. Your tradie will confirm the final price after assessing the job.

Methodology: Ranges are drawn from estimates generated through Leadkit's decking quote calculator using 2026 Australian labour and materials rates across Sydney, Melbourne, Brisbane and Perth. Leadkit's own tool is the data source — it uses real rates entered by tradies on the platform, not published averages.

How much does a 15m2 deck cost?

A 15m² deck costs $3,000–$8,250 installed in Australia in 2026. Treated pine lands at $3,000–$4,200, merbau hardwood at $4,200–$5,700, spotted gum or ironbark at $4,800–$6,300, and premium solid-core composite at $6,750–$8,250. Add $750–$1,500 if the deck sits more than 500 mm above ground.

A 15m² deck is about 5 m × 3 m — the most common size Australians build off a back door or sliding door, big enough for an outdoor table and six chairs without eating the whole backyard. It's also the size that sits neatly inside most councils' small-works thresholds, which matters for your total cost.

These are price indications only. Your tradie will confirm the final price after assessing the job.

Two things make a 15m² deck cheaper per square metre than you'd expect, and one makes it dearer. In its favour: at 15m² you're usually building a simple rectangle with no cuts around corners, posts or garden beds, so waste stays under 10%. Against it: fixed costs — site set-up, delivery, waste removal, the tradie's minimum day rate — get spread over fewer square metres, so small decks carry a higher share of overhead than a 40m² job.

Size also decides your paperwork. In NSW, a ground-level deck under 25m² can often be built as exempt development, so a 15m² deck frequently avoids a DA entirely — while in Victoria the trigger is height, not area, with a building permit required above 800 mm. That single difference can be worth $300–$1,500 in permit fees on an otherwise identical deck.

Across the quotes generated through Leadkit, decks in the 12–20m² band are the most commonly estimated size in the decking calculator — small enough to be a weekend-scale job for a two-person crew, large enough to justify a proper sub-frame rather than a floating platform.

Working out a 15m² budget? Run it through the free decking quote calculator — enter 15m² and your board type for an instant estimate on current Australian rates. If you're weighing a covered deck instead, the pergola cost guide for Australia covers the roofing side of the same project.

What does treated pine decking cost?

Treated pine decking costs $200–$280/m² installed, making it the cheapest structural decking material in Australia. A 15m² pine deck comes in at $3,000–$4,200; a 30 m² deck in Brisbane or Adelaide runs roughly $6,000–$8,400.

It's affordable, widely available, and when properly specified and maintained, it'll last 15–25 years.

The critical spec to check is H4 treatment. H4 is the minimum hazard level required for timbers in contact with, or close to, the ground in Australia. It means the pine has been pressure-treated with preservative to resist rot and termite attack. H3 is rated for above-ground use only — if a quote spec sheet says H3 for a ground-level application, push back.

Typical joist spacing for treated pine is 450 mm centres. Some builders space joists at 600 mm to save materials cost — this is acceptable for most decking boards but creates a springier feel underfoot and is generally not recommended for long-span decks. Ask your tradie what they're quoting.

You can browse treated pine options at Bunnings, but a decking tradie will almost always source from a timber merchant at better rates and more consistent grading than retail packs.

What does hardwood decking cost: merbau, spotted gum and ironbark?

Hardwood decking costs $280–$420/m² installed in Australia. Merbau sits at $280–$380/m² and premium species like spotted gum and ironbark at $320–$420/m². On a 15m² deck that's $4,200–$6,300 — roughly $1,200–$2,100 more than the same deck in treated pine.

Hardwood decks cost more upfront but repay the premium with decades of service and a look that composite or pine can't replicate.

Merbau is the most popular hardwood choice in Australia — it's naturally durable (Class 2 above ground, Class 2 in-ground), oils well, and weathers to a silver-grey if left untreated. Budget $280–$380/m² installed. The Housing Industry Association (HIA) notes hardwood remains the preferred finish for homeowners planning to hold their property long-term.

Spotted gum and ironbark are premium species — incredibly dense, highly slip-resistant (important for pools and wet areas), and rated Class 1 in-ground. Expect $320–$420/m² installed. The higher slip rating on spotted gum is worth asking about if the deck will be near a pool or in a shaded area that stays damp.

Hardwood grade matters. Select grade boards have minimal knots and tight grain. Feature grade allows more character marks and is 15–20% cheaper. Neither is structurally inferior — it's an aesthetic call.

Across quotes generated through Leadkit, the labour rate for hardwood decking tends to be 10–15% higher than treated pine because hardwood is harder to cut and fix and requires pre-drilling to avoid splits.

Composite decking: hollow core vs solid core?

Composite decking costs $350–$550/m² installed in Australia. Hollow-core boards run $350–$450/m² and solid-core premium boards $450–$550/m² — so a 15m² composite deck lands between $5,250 and $8,250.

Composite decking has gone mainstream in Australia over the last decade. Low maintenance (no oiling, no splintering), good colour stability, and long warranties have made it a genuine rival to timber.

The key distinction buyers miss is hollow-core vs solid-core construction.

Hollow-core boards (think ModWood, Futurewood, and lower-tier Ekodeck ranges) have voids running through the board. They're lighter, cheaper to produce, and adequate for most residential applications. Cost: $350–$450/m² installed.

Solid-core boards (Trex, premium Ekodeck, higher-end composite lines) are denser, quieter underfoot, more resistant to heat-related expansion, and carry longer warranties — often 25–30 years. Cost: $450–$550/m² installed.

One thing to ask about: slip rating. In wet areas, the AS 4586 slip resistance standard is worth referencing. Most quality composite boards are rated P4 or P5 — sufficient for around pools. Cheaper hollow-core boards can rate lower; confirm with your supplier.

Futurewood and Trex both publish their technical data sheets online — ask your tradie to confirm the rating for any composite product they spec.

Want a quick price check on a composite deck? Use the free decking quote calculator — enter your area in m² and it'll generate an instant estimate based on current rates.

What else affects the price of a deck?

After material choice, the three biggest cost variables are deck height, balustrades and stairs. Together they can add more to a quote than the boards themselves.

How much does deck height add?

A bearer (the main horizontal beam spanning between posts) and joist system at ground level is relatively simple work. Lift the deck 500 mm or more — for a sloped block, a hillside garden, or a second-storey deck — and the structural requirements change. The posts get longer, the bearers and joists get beefier, and in some states council approval or an engineer's certificate is required.

Expect to add $50–$100/m² for elevated decks — $750–$1,500 on a 15m² deck. Decks over 1 m above ground typically require balustrades, which adds again.

What do balustrades cost?

Balustrades are a significant cost line on any elevated deck — and they're not optional if the deck is more than 1 m off the ground (AS 1170 and the NCC set out the requirements). Expect:

• Timber balustrade: $250–$350/linear metre
• Glass (semi-frameless): $400–$600/linear metre
• Aluminium powder-coated: $300–$450/linear metre

On a 15m² deck with balustrade along two open sides (about 8 linear metres), that's $2,000–$4,800 on top of the deck itself — often the difference between a $4,000 job and a $9,000 one.

What do deck stairs cost?

A standard single flight of stairs — typically 4–8 risers — runs $1,500–$3,500 depending on the stringer material, tread type and whether it's a straight run or a curved design. Master Builders Australia recommends stairs be built to AS 1657 standards — your tradie should be across this without prompting.

Do you need a council permit?

Depending on your state and the deck's size, a permit may be required. In NSW, decks over 10 m² generally need development consent unless covered by exempt development provisions. In Victoria, a building permit is required for decks over 800 mm above ground. Budget $300–$1,500 for permit fees if they apply — your builder or landscaper should advise upfront.

For rules specific to your suburb, check your local council's planning portal or the relevant state authority (e.g. NSW Planning Portal, VCAT/VBA in Victoria).

When does the sub-frame need replacing?

If you're replacing old decking boards on a sound existing frame, the cost drops to board supply and laying only — but a rotted frame adds $100–$180/m² to the job. On a 15m² deck, that's $1,500–$2,700 before a single new board goes down.

Rotted bearers, rusted post brackets, or termite-damaged joists mean the frame needs to go too. A sub-frame replacement only (removing old frame, treating posts, installing new bearers and joists) runs $100–$180/m². Add this to your board supply and laying costs if the structure is compromised.

For older decks — particularly anything built pre-2000 with red ironbark or round posts — it's worth getting a builder to assess the sub-frame before you commit to new boards. A $15,000 hardwood reboard on a rotten frame is money poorly spent.

Browse the full range of outdoor and landscaping calculators to estimate related projects at the same time.

How do you get an accurate decking quote?

The fastest way to get comparable decking quotes is to fix your spec before you call — area in m², height above ground, timber type, and whether balustrades are needed. Tradies quoting the same brief produce numbers you can actually compare; vague briefs produce a $150/m² spread.

Getting three quotes is standard advice, but getting useful quotes takes a bit more prep.

Define your spec before you call. Know your approximate area in m² (a 15m² deck is 5 m × 3 m), the height above ground, whether you need balustrades, and the timber type you're leaning toward. This lets tradies quote apples-to-apples rather than guessing your brief.

Ask for a line-item quote. A professional decking tradie will break out materials, labour, waste removal, fixings and any subcontractor work (e.g. a structural engineer for elevated decks). Lump-sum quotes make it impossible to compare.

Check the treatment spec. For any treated pine, confirm H4 in writing. For hardwood, confirm the species and grade (select vs feature). For composite, get the brand name and product code.

Ask about the sub-frame. Will the quote include a new sub-frame or is it boards-over-existing-frame? This distinction alone can account for $80–$150/m² difference in quotes.

A good starting point before you call anyone: run a quick estimate through Leadkit's decking quote calculator to calibrate your budget. It takes about 30 seconds and gives you a ballpark per m² based on current Australian rates — so you're not walking into your first quote blind.

If you're also considering a pergola or patio alongside the deck, the pergola quote calculator can run a combined estimate. For any timber framing or carpentry work, the carpentry quote calculator covers custom joinery and structural timber work.

FAQs

Q: How much does a 15m2 deck cost in Australia?

A: A 15m² deck costs $3,000–$8,250 installed in Australia in 2026. In treated pine you'd pay $3,000–$4,200, in merbau hardwood $4,200–$5,700, in spotted gum or ironbark $4,800–$6,300, and in premium solid-core composite $6,750–$8,250. Add $750–$1,500 if the deck sits more than 500 mm above ground, and $2,000–$4,800 more if it needs balustrading along two open sides. A 15m² deck is roughly 5 m × 3 m. Run your own numbers through the decking quote calculator — these are price indications only, and your tradie will confirm the final price after assessing the job.

Q: What is the average decking cost per m² in Australia for 2026?

A: The average installed decking cost in Australia for 2026 sits between $200 and $450/m², depending on material. Treated pine decking is the most affordable option at $200–$280/m² installed, while composite decking ranges from $350–$550/m² and premium hardwood species like spotted gum and ironbark run $320–$420/m². Labour typically accounts for 40–55% of the total installed cost. These are indicative estimates — your tradie will confirm the final price after assessing your site and spec.

Q: How big is a 15m² deck?

A: A 15m² deck is about 5 m × 3 m, though 6 m × 2.5 m and 4 m × 3.75 m give you the same area in a different shape. It comfortably fits an outdoor dining table and six chairs, or a three-seater lounge setting with a coffee table and a barbecue. In NSW a ground-level deck at this size often falls inside exempt development provisions (under 25 m², under 600 mm high, set back from boundaries), which can save you a development application. In Victoria, height rather than area is the trigger — a building permit applies above 800 mm regardless of how small the deck is.

Q: Is composite decking worth the higher cost per m²?

A: For most homeowners who want low maintenance and long warranty coverage, composite decking is worth the premium. You'll pay $150–$250/m² more than treated pine upfront — about $2,250–$3,750 extra on a 15m² deck — but you'll skip the annual oiling, avoid splinters, and typically get a 25-year warranty on the boards. The lifetime cost comparison narrows significantly once you factor in restaining or replacing pine boards every 3–5 years. Solid-core composite is the better long-term choice over hollow-core if you're near a pool or in a high-UV area like Queensland or Perth.

Q: How much does labour cost for decking installation per m²?

A: Labour for decking installation in Australia runs roughly $80–$130/m², depending on the tradie's rates, your location, and deck complexity. On a 15m² deck that's $1,200–$1,950 of the total. Elevated decks, awkward access and stairs all push labour costs higher. In Sydney and Melbourne, rates are typically at the higher end of that range. Labour is almost always the bigger variable in quotes — materials are relatively consistent across suppliers, but tradies' day rates vary considerably.

Q: Do I need a permit to build a deck in Australia?

A: Permit requirements depend on your state and the deck's size, height and proximity to boundaries. In NSW, decks over 10 m² are generally subject to council approval unless they meet exempt development criteria (no larger than 25 m², no more than 600 mm above ground, set back from boundaries). In Victoria, a building permit applies to decks over 800 mm above ground. Queensland's requirements vary by local government area. Always check with your local council before starting — your licensed builder or landscaper should pull any required permits as part of the job.

Q: What's the cheapest deck material in Australia?

A: Treated pine is the cheapest structural decking material in Australia, starting from around $200/m² installed — about $3,000 for a 15m² deck. H4-treated pine is the correct spec for ground-level use. It's not the lowest-maintenance option — it needs oiling or staining every 2–3 years — but structurally it's entirely fit for purpose and widely available nationwide, including through the Bunnings Decking range for supply-only purchases. If budget is the primary driver, treated pine with a quality decking oil is the right call.

Q: How do I know if my existing deck sub-frame needs replacing?

A: Common signs include springy or bouncy boards, visible rust on joist hangers or post brackets, discolouration at the base of posts (rot), or any timber that crumbles or feels soft when you push a screwdriver into it. Termite damage typically appears as a hollowed-out timber core with a papery shell. If in doubt, have a licensed builder or pest inspector assess the frame before you invest in new boards. Sub-frame replacement runs $100–$180/m² — it's not cheap, but it's far less expensive than a structural failure.

Q: How does elevation affect the decking cost per m²?

A: Decks more than 500 mm above ground typically add $50–$100/m² to the base material and labour rate — $750–$1,500 on a 15m² deck. The extra cost covers longer posts, heavier bearers and joists, additional bracing, and in many cases council approval or an engineering certificate. Decks over 1 m above ground are also legally required to have compliant balustrades under the National Construction Code — budget $250–$600 per linear metre for balustrades depending on the type (timber, aluminium, or glass). For sloped blocks common in suburbs like the Hills District in Sydney or the Dandenong Ranges in Melbourne, the structural cost can push toward the higher end.

Q: Can I reduce my decking cost by doing some of the work myself?

A: Partially. Supply-only pricing for treated pine boards from Bunnings or a timber merchant is roughly $50–$90/m², so the labour component ($80–$130/m²) is a real saving if you have the skills. However, structural work — posts, bearers, joists, ledger connections to the house — requires a licensed carpenter or builder in most states, especially if a permit is involved. Attempting unlicensed structural work can void your home insurance and cause compliance issues when you sell. A sensible middle ground: hire a licensed tradie for the frame, then lay the boards yourself.

Final tips before you get quotes

Decking is one of those trades where the gap between the cheapest and the most expensive quote can be $150/m² — on a 15m² deck, that's a $2,250 spread on the same footprint, and the difference isn't always obvious until the deck is built.

A few things worth locking in before you start calling tradies:

• Get the species and treatment grade in writing — not just "hardwood" or "composite"
• Ask about joist spacing and whether the spec follows AS 1684 for residential timber framing
• Confirm whether the quote includes waste removal and all fixings
• Check if your tradie carries the relevant licence in your state (e.g. NSW Fair Trading builder's licence, or Queensland QBCC licence)

Ready to work out your decking budget? Use the free decking quote calculator — enter your area and deck type for an instant estimate based on current Australian rates. Takes 30 seconds, no signup needed. Results are a price indication; your tradie will confirm the final cost after assessing your job.