As of October 2026, building a new deck in Sydney typically costs about $205 to $690 per square metre installed, depending on the material. That is about $5,750 to $11,500 for a small 15 m² hardwood deck. These figures are indicative only and come from What’s The Damage’s Sydney decking guide; ranges in other guides vary.
How much does it cost to build a deck in Sydney?
As of October 2026, a new deck in Sydney typically costs about $205 to $690 per square metre installed. The material you choose makes a big difference. These prices are indicative only. They come from What’s The Damage’s Sydney decking guide (updated October 2026).
Typical Sydney prices per square metre:
- Treated pine: about $205 to $400
- Merbau hardwood: about $345 to $630
- Spotted gum hardwood: about $400 to $690
- Composite: about $320 to $630
The same guide gives these totals for a hardwood deck:
- Small deck, 15 m²: about $5,750 to $11,500
- Medium deck, 25 m²: about $9,200 to $18,400
- Large deck, 40 m²: about $14,950 to $29,900
Other cost guides give different ranges, so treat these as a starting point. Your price depends on your block, deck height and design.
Timber vs composite decking: which costs more?
What’s The Damage’s national timber vs composite guide puts installed hardwood at about $250 to $450 per square metre. Capped composite is about $380 to $600 per square metre. So composite often costs more up front.
The difference is upkeep. Timber needs oiling or sealing to stay in good shape. The same guide lists about $300 to $700 per treatment, and about $1,500 to $3,500 for a full sand and recoat. Composite usually needs cleaning rather than oiling.
Over 20 years, that guide estimates a 40 m² hardwood deck at about $21,000 to $34,900 in total. A capped composite deck comes to about $16,100 to $22,200. These are estimates. They depend on how often you maintain the deck.
Think about the look you want, how much upkeep you will do, and how hot the surface gets in full sun. Ask to see samples of both.
What drives the cost of a new deck
These are typical Sydney ranges from What’s The Damage.
- Size: bigger decks cost more in total, but often less per square metre.
- Height: an elevated deck adds about $57 to $205 per square metre for taller posts, bracing and safety.
- Steps and stairs: about $205 to $460 per step, or $1,150 to $5,200 for a full flight.
- Balustrades: about $170 to $520 per lineal metre. Glass and stainless steel sit at the higher end.
- Removing an old deck: about $23 to $63 per square metre.
- Site conditions: slopes, rock, poor drainage or tight access add labour.
- Footings and framing: the hidden structure is a big part of the price. It also decides how long the deck lasts.
- A roof or pergola: adding one over the deck costs about $5,750 to $17,250.
What a deck quote usually includes, and what it may leave out
Items that are often included:
- Footings, posts, bearers and joists
- Decking boards and fixings
- Basic steps
- Cleaning up and removing off-cuts
Items that are often left out, or priced separately:
- Removing an old deck
- Balustrades, gates and handrails
- Oiling or staining a timber deck
- Lighting, power points or built-in seating
- Engineering, council or certifier fees
- Drainage work under or around the deck
How to save money without cutting corners
- Keep it low: a deck close to the ground needs less structure and may not need a balustrade.
- Choose a simple shape: rectangles waste less material than angles and curves.
- Use standard board lengths: ask the builder to plan the size around them.
- Spend on the frame: a strong, well-built structure lasts longer than the boards on top.
- Think long term: compare the cost of timber upkeep with the higher up-front cost of composite.
- Check approvals first: knowing whether you need approval avoids costly changes later.
NSW rules that apply to decks
Approval: some decks can be built as exempt development without council approval. The NSW Planning Portal lists the standards. These include a deck area of no more than 25 m² and a floor height of no more than 1 metre above existing ground level. In most residential zones, the deck must be at least 900 mm from the boundary. There are also limits on the total area of such structures, and extra rules for heritage areas and bushfire-prone land. If your deck does not meet every standard, you may need a complying development certificate or council approval.
Licences: a contractor licence is needed in NSW for residential building work worth more than $5,000 including GST.
Licence check: look up the person or company on the NSW Government’s online licence check (verify.licence.nsw.gov.au). It shows the licence holder’s name, licence categories, expiry date and current status. Make sure the name matches the business on your quote and contract.
Written contract: your tradie must give you a written contract if the job is worth more than $5,000 including GST. Jobs over $20,000 need a more detailed contract, and you get a cooling-off period of five clear business days.
Deposit: the most you can be asked to pay as a deposit is 10 per cent of the contract price.
Home Building Compensation insurance: for work worth more than $20,000, the contractor must take out this insurance before asking you for any deposit or payment. It protects you as a last resort if the contractor can’t finish the job or fix defects because they have become insolvent, died, disappeared or lost their licence. Ask for the certificate.
Warranties: NSW law gives you statutory warranties on home building work. The period is 6 years for major defects and 2 years for other defects.
Safety: raised decks may need a balustrade under building rules. Ask your builder what your design needs.
Questions to ask your tradie
- What is your licence number, and does it cover this work?
- Does my deck meet the exempt development standards, or do I need approval?
- What timber or composite product will you use, and what grade?
- What footings and framing will you use, and what is the frame made of?
- Are steps, balustrades and oiling included?
- How will you handle the slope and drainage on my block?
- What upkeep will the deck need each year?
- What warranties come with the product and your work?
Get matched with local deck builders
Thinking about a new deck? Describe your job to MyTradeCrew. Tell us the rough size, how high off the ground it will be and whether you prefer timber or composite. We will match you with vetted, licensed and insured local deck builders who can visit your site and give you a written quote.
Frequently asked questions
How much does a deck cost per square metre in Sydney?
As of October 2026, What’s The Damage lists about $205 to $400 per m² for treated pine, $345 to $630 for merbau, $400 to $690 for spotted gum and $320 to $630 for composite in Sydney. These are indicative installed prices.
Is composite decking cheaper than timber?
Usually not up front. It often costs more to install than hardwood, but it does not need regular oiling. Over many years, total costs can end up closer than the starting prices suggest.
Do I need council approval to build a deck in NSW?
Not always. A deck may be exempt development if it meets every standard, including no more than 25 m² and no higher than 1 metre above ground. Otherwise you may need a complying development certificate or council approval.
How much does a 20 m² deck cost?
What’s The Damage lists a 15 m² hardwood deck in Sydney at about $5,750 to $11,500 and a 25 m² deck at about $9,200 to $18,400. A 20 m² deck would usually fall between these. Get a quote for your exact design.
How long does a timber deck last?
It depends on the timber, the build and the upkeep. What’s The Damage suggests hardwood can last 25 years or more with care. Ask your builder about your chosen product.
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