Key takeaways
- Small deck (15-25 m2 timber, ground level): $6,500-$12,000
- Medium deck (25-50 m2 timber, one stair set): $12,000-$28,000
- Medium composite deck (25-50 m2 Modwood/Trex): $18,000-$38,000
- Pool-surround deck (40-60 m2 timber, pool-rated balustrade): $22,000-$48,000
See the full price table, try the deck cost calculator, or compare 3 itemised quotes.
Deck Cost Adelaide: the 2026 price table
Structured Adelaide pricing - the data no SERP competitor publishes.
| Deck type | Indicative range |
|---|---|
| Small deck (15-25 m2 timber, ground level)Treated pine or merbau, no balustrade, simple ground-level build. | $6,500-$12,000 |
| Medium deck (25-50 m2 timber, one stair set)Merbau or hardwood, one set of stairs, partial balustrade. | $12,000-$28,000 |
| Medium composite deck (25-50 m2 Modwood/Trex)Capped composite boards, the maintenance-light option at a premium. | $18,000-$38,000 |
| Pool-surround deck (40-60 m2 timber, pool-rated balustrade)Pool-rated balustrade, slip-resistant surface, pool-fence integration. | $22,000-$48,000 |
| Restoration only (sand + oil, ~30 m2)Sand back, re-oil a structurally sound timber deck. | $1,400-$3,200 |
Indicative metro Adelaide ranges for 2026. Fitted, GST inclusive. Your itemised quotes will vary with site conditions.
What actually drives the price of an Adelaide deck
Four things move a deck price more than anything else. Area is the obvious one - more square metres, more cost. Material is the next: a treated pine deck at $250 per square metre and a premium composite at $920 per square metre are nearly 4 times apart for the same area. Height is the quiet one - a raised deck needs engineered footings, a braced frame and a mandatory balustrade, which a ground-level deck does not. And balustrading itself, at $220 to $480 per linear metre, adds up fast on a deck with a long exposed edge.
Site conditions then layer on top. Reactive-clay soil in Salisbury or Playford means deeper, costlier footings. Coastal corrosion at Glenelg or Semaphore means upgraded fixings. A sloping hills-face block in Mitcham or the Adelaide Hills means more structure. A builder who has seen your site prices these in; a phone quote that has not, will not.
Why Adelaide deck quotes vary so wildly
The most common frustration in Adelaide decking, straight from local Reddit and ProductReview threads, is quotes for the same job ranging from $14,000 to $38,000. That is not because one builder is honest and the others are crooks. It is because the quotes priced different decks.
One builder quoted 450 millimetre joist spacing and galvanised screws; another quoted 360 millimetre spacing and 316 stainless. One allowed for proper footings; another did not. One quoted merbau; another quoted treated pine. Without itemised quotes you cannot see any of this - you just see 3 different dollar figures and no way to choose.
This is exactly why Decking Adelaide gets you 3 itemised quotes on the same scope from BWC-licensed builders. Itemised means frame, boards, fixings, oil or stain, and balustrades as separate lines - so you can compare like for like and spot the quote that quietly cut a corner.
Per square metre quick reference (Adelaide, 2026)
As a rule of thumb, fitted: treated pine $250 to $400 per square metre; merbau $320 to $520; spotted gum or blackbutt $420 to $650; Modwood or mid-tier composite $480 to $720; Trex or premium composite $620 to $920.
Use those rates to sanity-check a quote, not to replace one. A quote far below the bottom of the relevant range is a warning sign - something has been left out. A quote far above the top should be itemised enough to explain why. The deck cost calculator on this site applies these rates to your dimensions for a quick estimate.
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Deck Cost Adelaide - frequently asked questions
A small ground-level timber deck of 15 to 25 square metres costs $6,500 to $12,000. A medium 25 to 50 square metre timber deck with one stair set runs $12,000 to $28,000. The same size in composite is $18,000 to $38,000. A 40 to 60 square metre pool-surround deck is $22,000 to $48,000. Most family decks land in the $12,000 to $28,000 range.
A low-level, ground-level treated pine deck is the cheapest, at roughly $250 to $400 per square metre fitted. It needs no engineered footings, no balustrade under 1 metre, and often no council approval under 600 millimetres. The trade-off is recoating every 12 to 18 months and a softer surface that dents.
Because the quotes priced different decks. One may have quoted wider joist spacing, galvanised rather than stainless screws, fewer footings, or a cheaper board species. Without itemised quotes you cannot see what changed. Three itemised quotes on the same scope - frame, boards, fixings, finish, balustrade as separate lines - is the only reliable way to compare.
A well-built, compliant deck that extends the living space generally adds appeal and value, particularly given Adelaide's outdoor-living climate. A poorly built or non-compliant deck can do the opposite - a deck that fails a pre-sale inspection becomes a liability. Building it properly, with a licensed builder, protects both the use and the resale value.
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