How much does decking cost in Adelaide?
Every deck we build is quoted on the actual site, but you should not have to book a quote just to get a ballpark. Here is an honest guide to what decking costs in Adelaide, from a team that has been building decks here for 15+ years.
Most decks we build in Adelaide cost $250 to $750 per square metre installed, including the subfloor: treated pine at the low end, hardwood in the middle and composite at the top. A typical 20 m² merbau deck comes to $7,000 to $12,000.
Typical Adelaide decking prices per square metre
Here is where most residential decks in Adelaide land. Treat these as honest ranges rather than fixed prices: your site, deck height and board choice all move the number, which is why the free quote exists.
Treated pine
$250 to $400 /m²
The budget friendly workhorse. Paint or stain it any colour, ideal where the budget has to stretch.
Hardwood: merbau, spotted gum, blackbutt
$350 to $600 /m²
The classic Aussie deck. Rich colour and grain that handles Adelaide summers well with regular oiling.
Composite
$450 to $750 /m²
Higher upfront, lowest upkeep. No oiling, no splinters, and it keeps its colour for decades.
Guide ranges for a typical residential deck on a straightforward site, installed including the subfloor, current 2026. Complex sites, raised decks and premium boards sit above these ranges.
What moves the price
Size and shape
A bigger deck costs more in total but usually less per square metre. Curves, angles and picture framed edges add labour.
Height and subfloor
A low deck over flat ground is the cheapest to build. Raised decks need bigger posts, more bracing and often a balustrade.
Board choice
Treated pine, hardwood and composite all sit at different price points, and premium boards within each range add more again.
Site access
Tight access means materials are carried in by hand and old decks are carried out the same way. It adds hours, not days.
Balustrades and stairs
Glass, wire or timber balustrades, stairs and built in seating are priced on top of the deck itself.
Approvals
A deck under 500 mm high and at least 900 mm from every boundary generally needs no approval in SA. Higher or closer decks do, which adds design and lodgement costs.
Deck or concrete: which is cheaper?
A plain concrete slab on flat ground is often cheaper per square metre than a deck. The gap closes on sloping blocks, where a slab needs retaining and fill but a deck simply sits on taller stumps. A deck also stays cooler underfoot than concrete in summer and can be repaired board by board.
What about repairs?
Repairs are priced after we look under the deck, because the subfloor decides whether a repair or a rebuild makes sense. See deck repairs and restoration for what we check and how a repair job runs.
What real decks roughly cost
Small treated pine deck · 12 m²
$3,000 to $5,000
A neat entertaining space off the back door, low to the ground.
Merbau entertaining deck · 20 m²
$7,000 to $12,000
The classic hardwood deck with quality fixings, oiled and sealed.
Large composite deck · 30 m²
$13,500 to $22,000
A big low maintenance outdoor room, built to shrug off the sun.
Large hardwood deck · 40 m²
$14,000 to $24,000
A big entertaining deck in merbau or spotted gum. Bigger decks often land lower per m².
Decking cost questions
Is composite decking more expensive than timber?
Upfront, yes. Composite boards cost more per square metre than most timbers. Over ten years the gap narrows, because composite needs no oiling or refinishing. If you plan to stay in the home long term, composite often works out comparable. See our composite vs timber comparison for the full picture.
How do I keep the cost of my deck down?
Keep the shape simple, keep the deck low, and choose treated pine or a mid range hardwood. A straightforward rectangle on flat ground is the most cost effective deck you can build.
Why do decking quotes vary so much between builders?
Cheaper quotes usually save money underneath, with a lighter subfloor, fewer stumps or budget fixings. That is where a deck fails first. We quote on an engineered subfloor and quality fixings every time, and we are happy to talk you through exactly what is included.
What is the most expensive part of a deck?
On raised or sloping sites it is usually the subfloor and the labour to build it: more posts, bigger bearers and bracing. On flat ground the boards themselves are the biggest line item, which is why board choice moves the price so much.
Do I need building indemnity insurance for a deck?
In South Australia, domestic building work over $20,000 that needs development approval must be covered by building indemnity insurance, arranged by the builder. Smaller decks, and decks that need no approval, sit outside that rule.
Is the quote really free?
Yes. We visit your site, measure up, talk through timber and layout options and give you a written quote with no obligation.
Get a real number for your backyard
Ballparks are a starting point. A free site visit gets you a fixed written quote for your actual deck: your soil, your access, your board choice. SA owned and operated, 15+ years experience.
Planning something specific? See our timber decking, composite decking, deck repairs or custom decking services.