How Much Does Decking Cost in Australia? (2026)

Last updated: 17 July 2026 · By Mossy Tariq, Founder — Property Blueprint Co.

Decking cost in Australia runs from around $120 per square metre installed for treated pine to $450 and beyond for hardwood and composite in 2026 — and that per-square-metre band is the least decisive number on the quote. The boards are the part of a deck you can see, which makes them the part every quote leads with. The substructure, the height above ground, the approval pathway, and the bushfire rating are the parts that decide whether a 25-square-metre deck lands at $6,000 or $18,000.

This guide prices the whole installed deck: boards, subframe, and labour per square metre by material tier, then the cost drivers underneath — footings, height, engineering, approvals by state, bushfire construction rules, and balustrades. The composite-versus-timber decision has its own comparison guide; this article is about what the finished, compliant, signed-off deck actually costs.

The boards are the price you compare. The substructure, the height, and the rules are the price you pay.

How much does decking cost per square metre in Australia in 2026

Installed decking — boards, subframe, and labour together — prices in three material tiers across Australian industry cost data for 2026. Treated pine typically runs $120 to $250 per square metre installed, with metropolitan quotes commonly landing at $200-plus. Hardwoods such as merbau and spotted gum run $250 to $450 per square metre installed. Composite sits in the same $250 to $450 installed band as hardwood, with premium boards and high-freight markets such as Perth pushing past it.

The installed rate decomposes into three lines, and a quote that shows them separately is a quote you can interrogate. Board material alone runs roughly $60 to $180 per square metre for timber depending on species and grade, and $100 to $170 for composite by quality tier. The subframe — joists, bearers, and posts — typically adds $40 to $80 per square metre. Labour runs about $50 to $120 per square metre, with simple ground-level rectangles at the bottom of that range and multi-level or curved work at the top.

Run the arithmetic on a standard entertaining deck and the band gets real: a 25-square-metre merbau deck at $250 to $450 installed lands between roughly $6,250 and $11,250 — before steps, balustrade, or any height premium enters the number. The same deck in treated pine prices from around $3,000 to $6,250 installed, and carries the highest maintenance bill of the three tiers across its life.

Every figure above describes the deck the quote assumes: near ground level, on a flat accessible site, outside a bushfire zone. The rest of this article prices the decks people actually build.

Why do two decks with the same boards quote thousands apart

Because the variable cost of a deck is underneath it. Two quotes for the same merbau boards over the same area can sit thousands of dollars apart, and the gap is almost always substructure and height, not timber.

Height is the single biggest driver. A deck raised more than a metre above ground moves into a different cost category: deeper footings, engineered design, taller posts and bracing, mandatory balustrades, and harder labour. Industry pricing data puts elevated decks at 30 to 50 per cent more than the equivalent low-level deck. A sloping block produces the same effect by stealth — one end of the deck is low-level, the other end is elevated, and the quote has to carry the expensive end.

Then the additions: steps commonly add $300 to $800 per step, and site preparation — excavation, spoil removal, difficult access — is priced per project, not per square metre. The practitioner detail to watch: footings are where decking quotes hide their provisional sums. A quote that carries "footings to suit site conditions" as an allowance is a quote that becomes a variation the day the post-hole digger hits rock or fill. Ask what footing depth the price assumes, and what happens to the number if the site does not cooperate.

When does a deck need council approval in Australia

The approval question is decided by height and size thresholds that differ by state, and the thresholds are tighter than most homeowners assume.

In New South Wales, a deck can be built as exempt development — no approval required — only while it stays within the State Policy limits: no more than 25 square metres, floor height no more than one metre above existing ground, no more than three metres at its highest point, behind the building line, and at least 900 millimetres from each boundary in standard residential zones. Step outside any one of those limits and the pathway becomes a complying development certificate or a development application.

In Victoria, the practical trigger is lower. Most decks with a structural subfloor need a building permit issued through a registered building surveyor, and the Building Regulations 2018 treat 800 millimetres above ground as the height at which a deck starts counting against siting and setback provisions. Planning overlays — heritage, bushfire, flood — can add a planning permit on top of the building permit even for a low deck.

In Queensland, a deck is accepted development — buildable without approval — only while it stays under 10 square metres, less than one metre above ground, with no side longer than five metres, under the Building Regulation 2021. Almost every entertaining deck exceeds that footprint, which is why most Queensland decks go through a private certifier. Queensland also sets the country's lowest licensing threshold: any building work valued over $3,300 including labour, materials, and GST must be carried out by a QBCC-licensed contractor — which captures effectively every professionally built deck in the state.

Two contract mechanics follow the approval question. In New South Wales, home building work worth more than $5,000 requires a written contract, and licensed trades everywhere should be quoting against a written scope — the HIA publishes standard minor-works contracts built for exactly this size of job. And an exempt deck is not a compliance-free deck: the structure still has to meet the residential timber-framing standard (AS 1684) and the National Construction Code, approval or no approval.

What do bushfire and balustrade rules add to a decking quote

In a designated bushfire-prone area, the site's Bushfire Attack Level (BAL) rating constrains the material list before price gets a vote. The National Construction Code applies AS 3959 — the bushfire construction standard — to decks attached to homes in those areas, and the rules are specific: decking within 300 millimetres of a glazed door or window that sits less than 400 millimetres above the deck surface must be non-combustible or a recognised bushfire-resisting timber. Merbau, spotted gum, blackbutt, and ironbark carry that classification; treated pine does not. At BAL-40 and BAL-FZ, balustrades and handrails must be non-combustible, and subfloor supports carry their own material rules. Composite is not automatically compliant — the specific product needs certified bushfire test documentation.

The cost consequence is direct: a BAL rating can delete the cheapest tier from the quote entirely, push the board specification from pine to hardwood or certified composite, and add ember-protection detailing under the deck. Confirming the BAL rating before the design is drawn is cheaper than re-specifying the deck after the certifier rejects it.

Balustrades are the other rule-driven line. Under the National Construction Code, a barrier is required wherever a person could fall one metre or more from the deck surface — at least one metre high, with openings no more than 125 millimetres, and with climbable-element restrictions once the fall exceeds four metres. Balustrade is priced per lineal metre on top of the decking rate, and the material decision multiplies it: a simple timber balustrade is the baseline, while stainless wire, aluminium, or glass can cost as much per metre as the deck beneath it. On an elevated deck, the balustrade line is routinely the difference between two quotes that look identical at the boards.

Which questions hold a decking quote to its number

A decking quote is held to its number by making the invisible lines visible before signing. These are the checks that do it:

1. Require the quote to separate boards, subframe, and labour. A single lump-sum rate per square metre cannot be compared against another quote, because the material tier and the structural allowance are blended into one number.
2. Ask what footing depth and ground conditions the price assumes. Footings are the classic provisional sum on a decking quote, and the variation arrives the day excavation finds rock, fill, or reactive soil.
3. Confirm the approval pathway in writing before work is priced. The quote should name whether the deck is exempt or accepted development, or needs a certifier or a permit — and who is responsible for obtaining it.
4. Confirm the site's BAL rating before the material is chosen. A bushfire-prone site narrows the board list to bushfire-resisting timbers or certified composite, and a quote written for pine on a BAL-29 site is a quote for a deck that cannot be signed off.
5. Get the balustrade specified by material and lineal metres. Any deck with a fall of one metre or more needs a compliant barrier, and the barrier can move the total by thousands depending on what it is made of.
6. Ask how height is measured across the whole footprint. On a sloping block, the high end of the deck sets the engineering, the approval, and the balustrade requirement — not the end nearest the house.

Where does the deck sit inside the whole outdoor project

A deck is one layer of an outdoor renovation, and it is rarely the layer that blows the budget. The outdoor renovation cost guide breaks the backyard into its five cost layers — site preparation, structure, surfaces, services, and finishes — and the deck sits in the surfaces layer, on top of preparation and drainage decisions that should be made first. Building the deck before the drainage, the levels, or the services are resolved is how a finished deck ends up with a trench cut through it.

Sequencing is where The 12-Phase System earns its place outdoors: the approval pathway resolved before design is locked, the BAL rating confirmed before materials are specified, the substructure priced before the boards are chosen, and the practical completion inspection done before final payment releases. The Outdoor Renovation Blueprint runs that sequence for the whole outdoor project — every layer, every trade, every hold point — with the deck priced inside the project it belongs to.

And if the number is the first thing you need, the free Renovation Cost Calculator gives you a trade-by-trade estimate in under 5 minutes — before your first trade conversation, with the deck priced alongside the rest of the backyard.

Frequently asked questions

How much does decking cost per square metre in Australia in 2026?

Installed decking — boards, subframe, and labour — typically costs $120 to $250 per square metre for treated pine, and $250 to $450 per square metre for hardwoods such as merbau and spotted gum or for composite, per Australian industry cost data. Elevated decks price 30 to 50 per cent higher because of engineering, deeper footings, and mandatory balustrades.

How much does a 25-square-metre deck cost in Australia?

At 2026 installed rates, a 25-square-metre treated pine deck prices from roughly $3,000 to $6,250, and the same deck in merbau or composite lands between roughly $6,250 and $11,250. Steps at $300 to $800 each, balustrades priced per lineal metre, elevated substructure, and difficult site access all add to those figures, which assume a low-level deck on a flat, accessible site.

Do I need council approval to build a deck in Australia?

Approval is decided by state thresholds on size and height. In New South Wales, a deck is exempt from approval only up to 25 square metres, one metre floor height, and three metres total height, behind the building line and set back from boundaries. In Queensland, the accepted-development limit is 10 square metres, under one metre high, with no side over five metres. In Victoria, most decks with a structural subfloor need a building permit through a registered building surveyor. Anything larger, higher, or in an overlay needs formal approval.

Who can legally build a deck in Australia?

In Queensland, any building work valued over $3,300 including labour, materials, and GST must be carried out by a QBCC-licensed contractor, which captures virtually every professionally built deck. Other states apply their own licensing and contract thresholds — in New South Wales, home building work over $5,000 requires a written contract. Whoever builds it, the structure must meet AS 1684 timber-framing requirements and the National Construction Code, even where no approval is needed.

What are the decking rules in bushfire-prone areas?

The National Construction Code applies AS 3959 to decks attached to homes in designated bushfire-prone areas. Decking within 300 millimetres of glazed doors or windows sitting less than 400 millimetres above the deck surface must be non-combustible or a recognised bushfire-resisting timber — merbau, spotted gum, blackbutt, and ironbark qualify; treated pine does not. At BAL-40 and BAL-FZ, balustrades and handrails must be non-combustible, and composite products need certified bushfire test documentation to be signed off.

When does a deck need a balustrade in Australia?

Under the National Construction Code, a barrier is required wherever a person could fall one metre or more from the deck surface. The balustrade must be at least one metre high with openings no greater than 125 millimetres, and decks with a fall of more than four metres face additional restrictions on climbable elements. Balustrade is priced per lineal metre on top of the decking rate, and material choice — timber, wire, aluminium, or glass — moves that line substantially.