Decking is usually priced per square metre, but the board is only part of the cost. The substructure, footings, height off the ground, steps and balustrade often decide the final figure more than the timber choice.
The ranges below are a starting point for budgeting and comparing quotes. Always get an itemised quote from a builder who has measured your site.
Decking Materials: Typical Adelaide Ranges
Treated pine (supplied + installed)
Around $200 to $350 per square metre. The most affordable option and easy to work with, though it needs regular oiling and will not last as long as hardwood or composite.
Hardwood (merbau, spotted gum, jarrah)
Roughly $350 to $550 per square metre. A premium natural look with strong durability. Board grade and species drive the range, and it still needs periodic maintenance.
Composite decking
About $400 to $700 per square metre. Higher upfront cost but very low maintenance and no oiling. Quality varies widely between brands, so compare warranties, not just price.
Figures are indicative 2026 Adelaide ranges to help you budget. They are estimates, not quotes. Always get a written itemised quote for your site.
What Moves the Decking Number
Height and substructure. A deck close to the ground is cheaper than one on tall posts. Elevated decks need more framing, taller footings and often balustrade, all of which add cost.
Footings and ground conditions. Reactive clay, slope or rock in Adelaide backyards means deeper or engineered footings. This is a common reason two quotes differ.
Steps and balustrade. Stairs, landings and compliant balustrade are separate cost lines. Anything above a certain height triggers a balustrade requirement.
Roof or pergola over. Adding cover turns a deck into an outdoor room and adds structure, roofing and possibly council approval. Often bundled with a verandah or pergola.
Council approval. Low freestanding decks may be exempt, but larger, elevated or attached decks usually need approval. Check before you commit.
How BuildPilot Helps
- *Review quotes and flag what is missing before you commit
- *Explain realistic budgets for your scope and site
- *Match you with builders who specialise in this work
- *Compare quotes on a like-for-like basis
Common Questions
In Adelaide in 2026, treated pine decking supplied and installed typically runs $200 to $350 per square metre, hardwood such as merbau or spotted gum sits around $350 to $550, and composite decking runs roughly $400 to $700. A typical 20 square metre deck therefore lands somewhere between $6,000 and $14,000. Height off the ground, footings, steps and balustrade move the number more than the board itself. Get an itemised quote from a deck builder who has seen your site.
Related Guidance
Planning a Deck in Adelaide?
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