Decks in Adelaide: what gets built
Most Adelaide back decks sit low, level with the back door and a step or two above the lawn. A low deck keeps the frame simple and, if it stays within SA’s limits, out of the approval system. A licensed deck builder quotes from the size, the height, the boards and the access to the back yard.
A low deck off the back door
Posts or adjustable steel stumps on concrete footings, a treated-pine or steel subframe, and decking boards fixed with screws suited to the timber. A gap between the frame and the house wall keeps the bricks or stone dry and lets air under the deck.
Decks on sloping blocks
On a block that falls away, a deck can step down in two levels rather than one high platform. Each level stays lower, which can keep it within the exemption and avoid a balustrade.
Steps, landings and screens
Wide timber steps down to the lawn, a landing at the side gate, or a slatted screen at one end. A screen on a fence counts as part of the fence under SA’s planning rules.
Replacing an old deck
When the boards and frame have had it, the old deck comes up, the footings are checked, and the new deck goes in on the same footprint. Old treated-pine posts are often CCA-treated, and EPA SA says CCA posts must go to an authorised landfill, never be burnt.
Deck costs in Adelaide
New deck prices from Adelaide deck builders
| What’s charged | Price | Source |
|---|---|---|
| New deck, per m² installed (pine, hardwood or composite) | $200 – $350 per m² | Bella Carpentry, Unley |
| Small basic deck, 10 m², treated pine or hardwood (Elizabeth South price bracket) | $3,000 – $5,000 | Paul’s Decking and Pergolas, Hectorville |
| Small deck, hardwood or composite (Unley price bracket) | $7,000 – $10,000 | Paul’s Decking and Pergolas, Hectorville |
| Large deck, 25–30 m², composite boards and built-in seating (Elizabeth South price bracket) | $12,000 – $18,000 | Paul’s Decking and Pergolas, Hectorville |
Published by two Adelaide deck builders, checked 28 October 2026: Bella Carpentry (undated page; “depending on the materials used, the complexity of the design, and site conditions”) and Paul’s Decking and Pergolas (24 July 2025, prices by suburb price bracket). Neither says whether GST is included. These are their published guides, not a quote: height, steps, access and the boards chosen set a deck’s own price.
Size, height, the number of steps, access to the back yard and the boards decide the price, and a licensed deck builder puts theirs in writing after seeing the site. The deck cost guide adds national prices by timber and the PlanSA fees for a deck that does need approval.
Does a deck need approval in SA?
Under Schedule 4 of the Planning, Development and Infrastructure (General) Regulations 2017, a deck used with an existing home is exempt from approval only if no point of its floor is more than 500 mm above the natural surface of the ground, and no part of it is within 900 mm of a boundary.
The exemption doesn’t apply in a bushfire-prone area, in the Historic Area Overlay, or at a local or State heritage place. Outside those limits a deck needs development approval through PlanSA. Check your address with PlanSA’s approval wizard, and see the deck and pergola approval guide.
Every deck needs a licensed contractor
Approval and licensing are separate questions. Even a deck that’s exempt from approval is building work under SA’s Building Work Contractors Act, so it’s built by a licensed contractor whose licence covers decks.
Choosing the decking boards
Merbau
A dense, reddish-brown hardwood and a common choice in Adelaide. It bleeds tannin when new, so keep it off pale paving for the first few rains or give it a wash.
Spotted gum and other Australian hardwoods
Hard, heavy and long-lasting, with a lighter grey-brown colour that weathers to silver if it isn’t oiled.
Treated pine
The lower-cost choice. It needs oiling more often and moves more than hardwood, but it suits a deck that will be stained or painted.
Composite boards
No oiling, but the boards cost more and get hot in Adelaide’s summer sun. They’re fixed to the manufacturer’s spacing and fastener rules.
Deck balustrades, bushfire and the coast
The National Construction Code requires a barrier where it’s possible to fall 1 m or more from the deck. On a deck the barrier must be at least 1 m high, and its gaps must not let a 125 mm sphere through (NCC Housing Provisions 11.3).
In a designated bushfire-prone area, SA’s Ministerial Building Standard MBS 008 sets a Bushfire Attack Level for the site, which decides the timber and fixings for a deck attached to the house. Near the coast, ask for stainless or hot-dip galvanised fixings: salt air corrodes plain steel.
What to send us
- The rough size of the deck, and photos of where it’ll go
- How high the floor will sit above the ground at its highest point
- How close the deck comes to the nearest boundary
- The boards you have in mind, and whether you want steps or a screen
- Whether the home is in a heritage area or near bushland, if you know
Related guides
- Do you need approval for a deck or pergola in SA? The Schedule 4 tests: decks up to 500 mm high and 900 mm from a boundary, open pergolas up to 4 m, and why a verandah always needs approval.
- Deck cost in Adelaide Adelaide deck builders’ published prices per m² and per deck, national prices by timber, sanding and oiling, and PlanSA fees.
Questions about decks in Adelaide
How high can a deck be without approval in SA?
No point of the floor more than 500 mm above the natural ground, and no part within 900 mm of a boundary. The exemption doesn’t apply in a bushfire-prone area, the Historic Area Overlay or a heritage place. See the approval guide.
Does a deck builder need a licence in SA?
Yes. Building a deck for someone else is building work under the Building Work Contractors Act 1995, with no dollar threshold. Some licences are limited to decks up to 1 m above the ground. See how to check a licence.
Can a deck be built over old pavers or concrete?
Often, if the slab is sound and drains. A deck over concrete still needs space under the boards for air, so the frame height has to allow for it. Send a photo of the area.
Do I need a balustrade?
The National Construction Code requires a barrier where you could fall 1 m or more from the deck. A lower deck doesn’t need one under that rule, though a rail at the steps is common.
Where this information comes from
The rules and figures on this page come from these published pages, checked on 28 October 2026.
- Bella Carpentry: decking Adelaide (FAQ) · Unley carpentry business, service page, undated
- Paul’s Decking and Pergolas: what a new deck means for property value in Adelaide · Hectorville deck and pergola builder, blog post, 24 July 2025
- What’s The Damage: decking cost 2026 · National cost guide (paid by tradespeople for enquiries), updated October 2026, prices include GST
- Stain And Seal: deck sanding in Adelaide · Goodwood deck restoration business, service page, updated 25 August 2026
- PlanSA: fees and charges at a glance, July 2026 · SA Government (Department for Housing and Urban Development), fee schedule from 1 July 2026
- Planning, Development and Infrastructure (General) Regulations 2017, Schedule 4 · South Australian regulations: Schedule 4 cl 4 (exempt decks, pergolas, fences, sheds, retaining walls)
- PlanSA: why you need approval · SA Government planning portal guidance, with the approval wizard
- Building Work Contractors Act 1995 (SA) · South Australian legislation: ss 3, 6, 28–36, 47A–47D, 49 and 50
