decking guide · 2026
How much does decking cost per square metre?
What published Australian price guides say an installed deck costs per m² in 2026, by board type, and the extras that change the total. We show every source and its date, so you can check them yourself.
BC Complete · Dapto NSW · Updated
The short answer
Across seven Australian price guides, most updated in 2025 or 2026, an installed deck runs roughly:
- Treated pine: $180–$400 per m²
- Hardwood (Merbau, spotted gum, blackbutt): $300–$715 per m²
- Composite: $250–$805 per m²
Stairs, balustrades and building the deck up off the ground all come on top. These are other businesses' published ranges, not BC Complete prices. Every deck we build is priced as a fixed-price quote after a free design meeting.
We build decks across the Illawarra from our base in Dapto. People often ask us for a price per square metre before we've seen the site. The honest answer is that the board is only part of it, so this guide sets out what published sources say, where they disagree, and what pushes a real deck up or down the range.
Cost per m² by board type
These are installed prices (supply and build) per square metre of deck, as printed by each source. The range is the lowest low to the highest high across the sources, not an average.
| Board | Range across sources | What each source says |
|---|---|---|
| Treated pine | $180–$400 | $180–$350[2] · $200–$350[1] · $205–$400 (Sydney)[3] · $200–$250[7] · timber $200–$400[6] |
| Hardwood Merbau, spotted gum, blackbutt | $300–$715 | $300–$550[1] · $300–$620[2] · $345–$715 (Sydney)[3] · Merbau $300–$350[4] · Merbau up to $320[7] |
| Composite | $250–$805 | $250–$450[6] · $280–$650[1] · $280–$700[2] · $320–$805 (Sydney)[3] · from $350[4] |
| Premium or capped composite | $450–$1,025 | $450–$900[2] · $520–$1,025 (Sydney)[3] · $650–$1,000+[1] |
One publisher breaks hardwood down by species. Its national page gives Merbau at $300–$550 per m², spotted gum at $350–$600 and blackbutt at $330–$620[2]. Treat that as one source's view, not a rule: in practice the species price moves with supply.
Photos from our own jobs.
The extras: height, stairs, balustrades
The per-m² figures above are for the deck itself. These are priced on top:
| Extra | What the sources say | Notes |
|---|---|---|
| Building it up off the ground | +$50–$180 per m²[2] · +$57–$205 per m² (Sydney)[3] · or 30–60% more per m²[1] | Taller posts, deeper footings, bracing and often engineering. Only two publishers price it. |
| Balustrade | $150–$400+[1] · $150–$450[2] · $170–$520 (Sydney)[3] · $150–$400[6] per metre · timber and wire from $180, glass around $320 per metre[4] | Priced per lineal metre of edge. |
| Stairs | $180–$400[2] · $205–$460 (Sydney)[3] · $200–$500[6] per step · $1,000–$5,200 a flight[2][3] | Priced per step or per flight. |
| Removing an old deck | $20–$55 per m²[2] · $23–$63 per m² (Sydney)[3] | One publisher only. |
| Council, certifier or engineering fees | No source gives a figure | Depends on the approval route. An exempt deck has none. |
Once a deck is around a metre off the ground it usually needs a balustrade under the building code, so a raised deck tends to carry all three extras at once. That's why raised decks on sloping Illawarra blocks cost noticeably more per square metre than a low deck on flat ground.
Worked examples
To show how the ranges combine, here is the arithmetic for a 20 m² hardwood deck (about 4 m × 5 m) using the published ranges above. This is arithmetic on other people's numbers, not a quote.
| At ground level | Raised, with stairs and a balustrade | |
|---|---|---|
| Deck, 20 m² × $300–$715 | $6,000–$14,300 | $6,000–$14,300 |
| Raised: 20 m² × +$50–$205 | — | $1,000–$4,100 |
| Balustrade: 10 m × $150–$520 | — | $1,500–$5,200 |
| Stairs: 5 steps × $180–$500 | — | $900–$2,500 |
| Total | $6,000–$14,300 | $9,400–$26,100 |
Two things stand out. First, the same 20 m² of deck can cost more than twice as much once it's raised and fenced. Second, the ranges are so wide that the arithmetic alone can't price your deck. It can only tell you which end of the range to expect.
Some sources also publish whole-deck totals that come out well below the per-m² figures. One lists $3,800–$5,300 for a whole 20 m² deck[5], yet the same page puts NSW labour alone at $200–$210 per m², which is $4,000 or more for 20 m² before any timber. The two kinds of figure don't reconcile, so don't mix them.
What does a 20x20 deck cost?
"20x20" comes from American sites, and it means 20 feet by 20 feet. That's about 6.1 m × 6.1 m, or 37 m². No Australian price guide we found prices a 20x20 deck, so here is the arithmetic using the ranges above, for the deck alone at ground level:
| Board | 37 m² × range | About |
|---|---|---|
| Treated pine | 37 × $180–$400 | $6,700–$14,800 |
| Hardwood | 37 × $300–$715 | $11,100–$26,500 |
| Composite | 37 × $250–$805 | $9,300–$29,800 |
Add stairs, balustrades and height on top. One more thing to know at this size: a 37 m² deck is well over the 25 m² limit for building a deck with no approval in NSW, so it will need a Complying Development Certificate or a development application. See approvals below.
Why the ranges are so wide
- →The board. Treated pine sits at the bottom, hardwood and composite overlap in the middle, and premium composite sits at the top.
- →Height. A raised deck needs taller posts, deeper footings and bracing, plus a balustrade.
- →The site. Slope, rock, tight side access and an old deck to remove all add labour. Many Illawarra blocks under the escarpment are sloping.
- →Coastal exposure. Near the surf we use stainless or marine-grade fixings, which cost more than standard ones but don't rust out.
- →Where you are. The same publisher's Sydney figures run higher than its national ones[2][3].
- →The sources themselves. Most are lead-generation or directory sites that don't publish their method, and two of the seven are the same publisher. Read them as a rough guide, not a price list.
Running costs: oiling and upkeep
Timber decks need regular oiling to hold their colour and stop the boards drying out. One publisher puts sanding and oiling at $25–$60 per m² and a re-oil without sanding at $15–$45 per m²[2] ($29–$69 and $17–$52 in Sydney[3]). Composite boards don't need oiling[1]: a wash-down is enough.
So the cheapest deck to build isn't always the cheapest to own. If you're weighing hardwood against composite, compare the up-front difference with the cost and effort of oiling a timber deck every year or two for as long as you live there. Our decking page compares the boards side by side.
Is concrete cheaper than a deck?
We couldn't find a reliable published comparison, so we won't quote one. What we can say is that it depends mostly on the ground. A concrete patio has to sit on level ground, so on a sloping block the ground has to be built up and retained first. A deck spans over the slope on posts and footings. On flat ground the comparison is much closer, and it comes down to the finish you want. If you're deciding between the two, we can look at your site and tell you which makes more sense.
Do approvals add to the cost?
Not if the deck is exempt development. In NSW a deck needs no approval if it meets every exempt rule, including:
- ✓No more than 25 m² in area, and all the decks, patios and similar structures on the lot together no more than 15% of the home's ground floor area (or 25 m² on lots of 300 m² or less)
- ✓A floor no more than 1 m above the ground, and no higher than 3 m overall
- ✓At least 900 mm from each side and rear boundary (5 m in rural and R5 zones), and behind the front building line
A deck outside those limits needs a Complying Development Certificate or a development application, which adds application fees, drawings and sometimes engineering. No published source gives a dollar figure for those, because they vary with the project and the certifier. Our council approval guide explains the three routes.
How to get an accurate price
The quickest way to a real number is to give a builder the things that move the price:
- Rough size, in metres. Pace it out if you need to.
- Height off the ground at the highest corner.
- Photos of the space, the slope and the side access.
- Your board preference, or the look you're after.
- Extras: stairs, balustrade, a roof over it, lighting.
Then book a free design meeting. We measure up on site, bring board samples, and send you a fixed-price quote that says exactly what's included.
Prices in this guide are other publishers' figures, read on 8 October 2026. They aren't BC Complete prices and they change over time.
questions, answered
Decking cost — FAQs
What is the average cost of decking per square metre in Australia?+
Published guides don't agree on an average, so we show the spread instead. Across seven Australian price guides, most updated in 2025 or 2026, an installed deck runs about $180–$400 per m² in treated pine, $300–$715 in hardwood and $250–$805 in composite, before stairs, balustrades or height.
How much would a 20x20 deck cost?+
A 20x20 deck is 20 feet by 20 feet, about 37 m². Using the published per-m² ranges, the deck alone works out at roughly $6,700–$14,800 in treated pine, $11,100–$26,500 in hardwood and $9,300–$29,800 in composite, before extras. At 37 m² it is also over the 25 m² exempt limit in NSW, so it needs approval.
How much should I budget for a deck?+
Start with the area times the per-m² range for your board, then add stairs, a balustrade and a raised-deck allowance if it sits well off the ground. A 20 m² hardwood deck works out at about $6,000–$14,300 at ground level and $9,400–$26,100 raised with stairs and a balustrade, using published ranges. A fixed-price quote is the only firm number.
Is it cheaper to concrete or build a deck?+
It depends mostly on the ground. On a sloping block, a concrete patio needs the ground built up and retained first, while a deck spans the slope on posts. On flat ground the two are closer. We couldn't find a reliable published comparison, so rather than quote a rule of thumb we can look at your site and tell you which makes more sense.
What is the cheapest decking material?+
Treated pine is the cheapest to install, at about $180–$400 per m² across published guides. It needs regular oiling or staining, so the running cost is higher than composite, which needs no oiling.
Does a raised deck cost more?+
Yes. Published guides add about $50–$205 per m² for a raised deck, or 30–60% more per m², for the taller posts, deeper footings and bracing. A deck around a metre or more off the ground usually also needs a balustrade, which is priced per metre on top.
How much does a deck balustrade cost?+
Published guides put a deck balustrade at about $150–$520 per lineal metre, depending on the style. One directory gives timber and wire from $180 per metre and glass at around $320 per metre.
Do you publish your own decking prices?+
No. Every deck is different, so we give a fixed-price quote after a free design meeting on site. The figures in this guide are other publishers' ranges, shown with their sources and dates.
Sources
- Karven, "Decking Cost Australia 2026", updated 3 June 2026. www.karven.com.au. Read 8 October 2026.
- What's The Damage, "Decking cost (national)", last verified October 2026. whatsthedamage.com.au. Read 8 October 2026.
- What's The Damage, "Decking cost Sydney", updated October 2026. whatsthedamage.com.au. Read 8 October 2026.
- Yellow Pages, "How much does decking cost per m2?", last updated May 2026. www.yellowpages.com.au. Read 8 October 2026.
- Airtasker, "Deck cost", last updated 25 April 2025. www.airtasker.com. Read 8 October 2026.
- Brite Decking, "How much does a deck cost?", undated. www.britedecking.com.au. Read 8 October 2026.
- Trade Builders Supplies, "What is the cost of timber decking in Australia?", undated. tradebuilderssupplies.com.au. Read 8 October 2026.
Want a real number for your deck?
Book a free design meeting. We measure up, bring samples and send a fixed-price quote.