How much does decking cost in Perth?
The timber you choose is the biggest lever on a Perth deck quote. Installed, treated pine costs $190–$370 a square metre, blackbutt $345–$650 and merbau $315–$580, while composite boards are $295–$735. For a finished deck in hardwood, budget $5,250–$10,500 for a small one and $13,650–$27,300 for a large one. Most Perth homes are separate houses, each on its own block, so the WA planning and permit rules written for a house lot are the ones most deck owners here work under. All prices include GST.
Comparing cities, or after the Australia-wide picture? See the national guide: Decking cost in Australia.
Detailed Pricing — Decking Cost in Perth 2026
| Service | Low | Typical | High |
|---|---|---|---|
| Treated pine deck (per sqm) | $190/sqm | $275 | $370 |
| Hardwood deck — merbau (per sqm) | $315/sqm | $440 | $580 |
| Hardwood deck — spotted gum (per sqm) | $370/sqm | $505 | $630 |
| Composite deck (per sqm) | $295/sqm | $580 | $735 |
| Small deck (15 sqm, hardwood) | $5,250total | $7,900 | $10,500 |
| Medium deck (25 sqm, hardwood) | $8,400total | $12,600 | $16,800 |
| Large deck (40 sqm, hardwood) | $13,650total | $19,950 | $27,300 |
| Deck steps (per step) | $190/step | $315 | $420 |
| Deck balustrade / railing (per lm) | $160/lm | $295 | $470 |
| Deck sanding + oiling (per sqm) | $26/sqm | $42 | $63 |
| Old deck demolition + removal | $21/sqm | $37 | $58 |
| Pergola over deck (basic timber or aluminium, about 4 x 4 m to 4 x 6 m) | $5,250total | $8,400 | $15,750 |
| Deck stairs (per flight, installed) | $1,050installed | $2,100 | $4,725 |
| Elevated / high-set deck surcharge (per sqm) | $52/sqm | $105 | $190 |
| Deck re-oil only (clean + 2 coats, no sanding, per sqm) | $16/sqm | $32 | $47 |
| Hardwood deck — blackbutt (per sqm) | $345/sqm | $470 | $650 |
| Composite deck — premium capped / solid-core, Trex class (per sqm) | $470/sqm | $600 | $945 |
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Prices include GST. Based on Perth metro area, October 2026. Outer suburbs may vary.
Perth's Decking Market in 2026
Perth's decking market is shaped by factors you won't find in any other Australian city. The combination of extreme summer heat, sandy coastal soils, and Western Australia's unique timber supply chain means the decisions you make here are fundamentally different to what works in Sydney or Melbourne.
Jarrah is your local advantage. Western Australia is the only place in Australia where jarrah grows commercially, which means Perth homeowners can source this premium hardwood at significantly lower cost than importing spotted gum or blackbutt from the eastern states. A jarrah deck in Perth typically costs less than merbau, which needs to be imported from Southeast Asia (jarrah is not a line in our Perth table; merbau is $315–$580/sqm installed). Jarrah is naturally termite-resistant, weathers to a beautiful silver-grey, and handles Perth's dry heat without the cracking issues that plague some imported timbers.
Surface temperature is a real design factor. Perth regularly hits 40°C+ in summer, and a north-facing deck in direct sun can reach surface temperatures above 65°C on dark composite boards. Timber stays noticeably cooler underfoot — roughly 15–20°C cooler than dark composites in direct sun. If your deck will get heavy barefoot traffic in summer (around a pool, for example), this matters more than almost any other consideration. Light-coloured composites have closed the gap somewhat, but natural timber remains the coolest option in Perth's climate.
Sandy soils change your foundations. Much of Perth sits on deep sand, particularly in the coastal suburbs from Scarborough through to Rockingham. Sandy soil doesn't compact the same way as clay, which means your deck footings may need to go deeper or use screw piles instead of standard concrete pads. This adds to the total build depending on the deck size and soil conditions at your specific site. A good builder will check soil conditions before quoting — if they don't, that's a red flag.
WA's building boom affects pricing. Perth's construction sector has been running hot since 2023, with strong interstate migration pushing housing demand. This means tradie availability for decking is tighter than pre-2020, and lead times of 4–8 weeks for a decking build are common. Booking in autumn (March–May) or late winter (August) often gets you better availability and pricing than the peak summer build season.
How Decking Costs Vary Across Perth
Perth's geography — stretched along 150km of coastline with distinct inland and hills zones — creates meaningful price variation depending on where you live.
Coastal suburbs (Scarborough, Cottesloe, Fremantle, City Beach): Salt spray within 1km of the ocean is corrosive to standard steel fixings and accelerates weathering on untreated timber. You'll need marine-grade stainless steel screws and brackets, which adds to the cost of the build. Composite boards actually perform well in coastal environments since they don't absorb salt moisture, making them a genuine option here despite the heat trade-off. Coastal jobs typically run above inland Perth pricing. Access can also be tighter in older established suburbs like Cottesloe and Fremantle, where narrow side passages and heritage considerations add complexity.
Perth Hills (Kalamunda, Mundaring, Roleystone): Sloping blocks are the norm, which means more structural engineering and potentially elevated deck designs with posts and bearers. A deck on a sloped hills site can cost 30–50% more than the same deck on a flat coastal block, purely due to the substructure required. Bushfire Attack Level (BAL) ratings are the other major factor — much of the hills is BAL-29 or higher, which restricts some timber species and composite products. Your builder needs to confirm BAL compliance before specifying materials. The upside: the hills suburbs tend to have mature trees providing natural shade, which extends the life of timber decking significantly.
Northern corridor (Joondalup, Wanneroo, Two Rocks): Newer housing estates with good vehicle access and flat blocks make these the most straightforward decking builds in Perth. Pricing here tends to be at or slightly below the metro average. Many homes in these suburbs are relatively new (post-2005), so existing outdoor areas are often concrete slabs that can serve as a base for decking overlays — a cost-effective option versus a full ground-up build.
South of the river (Rockingham, Mandurah, Baldivis): Similar to the northern corridor in terms of new housing stock and good access. The key difference is the high water table in some Mandurah and Rockingham areas, which can affect footing design. Extremely sandy soil is also more prevalent here than in the inner metro, making screw piles the preferred foundation method. Pricing is generally 5–10% below the inner-metro average due to lower tradie travel costs and simpler site conditions.
Decking cost per m² in Perth (2026): treated pine, merbau, spotted gum and composite
Decking in Perth costs $190–$630 per square metre built, depending on the board: treated pine $190–$370/m², merbau $315–$580/m², spotted gum $370–$630/m² and composite $295–$735/m². Per square metre covers the posts, bearers, joists and boards on a low-set deck. As whole jobs in hardwood: a small 15 m² deck is $5,250–$10,500, a medium 25 m² deck $8,400–$16,800 and a large 40 m² deck $13,650–$27,300. Balustrade is $160–$470 per metre on top.
| Job | Low | Typical | High |
|---|---|---|---|
| Treated pine deck (per m²) | $190/m² | $275 | $370 |
| Hardwood deck — merbau (per m²) | $315/m² | $440 | $580 |
| Hardwood deck — spotted gum (per m²) | $370/m² | $505 | $630 |
| Composite deck (per m²) | $295/m² | $580 | $735 |
| Small deck (15 m², hardwood) | $5,250 | $7,900 | $10,500 |
| Medium deck (25 m², hardwood) | $8,400 | $12,600 | $16,800 |
| Large deck (40 m², hardwood) | $13,650 | $19,950 | $27,300 |
| Deck balustrade / railing (per m) | $160/m | $295 | $470 |
Timber vs composite decking in Perth: treated pine is the cheapest board and needs the most upkeep; merbau and spotted gum are the hardwoods most Perth decks are built in, oiled every year or two; composite costs about what hardwood does per square metre but is never oiled, and the saving is in the years after. The frame under all four is the same, so the board choice is most of the per-metre difference.
What moves a decking quote in Perth:
- Height: a low-set deck is the base; an elevated deck needs bigger posts, bracing, balustrade and often an engineer.
- Size and shape: per-metre rates fall on a plain rectangle and rise with curves, cut-outs and multiple levels.
- Board and fixing: hardwood with concealed fixings is slower than face-screwed pine.
- Ground and footings: concrete footings into sand, clay or rock, and the number of posts, sit under every quote.
- Extras: stairs, balustrade, a pergola, lighting and a privacy screen are priced on top.
For a decking quote in Perth that compares, give the square metres, the height off the ground, the board you want and whether stairs or balustrade are needed.
What Affects Decking Costs in Perth
Merbau, blackbutt or spotted gum
Our Perth table prices three hardwoods. Merbau is the cheapest of them at a typical $440, blackbutt comes next at $470, and spotted gum is the dearest at $505. Colour, hardness and how each board holds its finish differ, so look at oiled samples before deciding, not just the rate.
Composite under a hot sun
February is the hottest month at the Perth Metro station, with an average top of 31.7 °C, and December brings just 9.6 mm of rain (BOM averages), the kind of long, dry heat that strips oil from timber quickly. Composite skips that upkeep, but it is not the cheap option: its typical rate of $580 is above merbau, and premium capped or solid-core boards run $470–$945.
Planning approval on a house lot
Under WA planning regulations, a deck on the same lot as a single house or grouped dwelling needs no development approval when the R-Codes apply, the work meets their deemed-to-comply provisions and the place is not heritage-protected. Outside those conditions, talk to your council early. Building permits are assessed by your local government, and Schedule 4 of the Building Regulations lists the work that needs no permit at all.
Shade over the deck
An open pergola over the deck costs $5,250–$15,750. In WA a pergola is unroofed, though it can carry open-weave shade cloth, and one built with a house needs no building permit if it is no more than 2.4 m high and covers no more than 20 square metres. Fit a solid roof and it becomes a patio, a Class 10a building, and permit rules apply.
Big blocks and family homes
Perth's housing is 77.8% separate houses, and close to half of homes (45.7%) have at least four bedrooms, well above the 34.8% national share (ABS 2021 Census). Bigger homes tend to want bigger decks, and the per-square-metre cost eases a little with size: a large deck at $19,950 works out cheaper per square metre than a small one at $7,900.
Height, stairs and balustrades
Building up to a raised floor adds $52–$190 a square metre for the taller frame. Stairs are priced $190–$420 a step, or $1,050–$4,725 for a full flight. A balustrade becomes compulsory once the deck stands more than a metre above the ground, and costs $160–$470 per lineal metre of edge.
How to Save Money on Decking Cost in Perth
Frequently Asked Questions — Decking Cost in Perth
Our Methodology
These are independent estimates from public cost guides, marketplaces and industry rate data, and no tradesperson can influence them, so always get a few quotes. Last reviewed October 2026. Read our full methodology →
Five deep-dives on Perth decking cost
