A comprehensive Sydney deck cost guide covering timber vs composite pricing, what affects cost, sample project costs, and how to get accurate quotes from builders.
If you're planning a deck for your Sydney home, you're probably wondering what it will actually cost. The answer is less straightforward than you'd hope, because deck costs vary significantly based on materials, size, site conditions, and design complexity.
Here's what you can expect: most professionally built new decks in Sydney cost between $350 and $950 per square metre, with premium projects going higher. For a typical 30m2 deck, you're looking at $10,500 to $28,500, depending on the timber or composite material you choose and the complexity of your build. Re-decking (replacing boards on an existing frame) is more affordable, typically $250 to $600 per m2.
This guide breaks down deck costs by material type, explains what affects the price for your specific project, and helps you understand what should be included in quotes so you can compare builders accurately.
Here's a snapshot of typical deck costs in Sydney for 2026:
This includes subframe (bearers, joists, posts), footings, decking boards, fixings, and labour.
Cost per square metre (installed):
Total project costs for common sizes:
These prices include materials, labour, subframe, fixings, and basic site preparation. They don't usually include complex excavation, council approvals, balustrades, or extensive structural work.
If your existing subframe is in good condition, you can save significantly by replacing just the decking boards. This is common when boards are worn, splintering, or weathered but the structure underneath is still solid.
Cost per square metre (installed):
Re-decking typically includes removal of old boards, inspection and minor repairs to the subframe, new decking boards, fixings, and oiling or sealing if using timber.
Timber remains the most popular choice for Sydney decks, with options ranging from budget-friendly treated pine to premium Australian hardwoods.
Treated pine is the most affordable timber option. It's softwood that's been pressure-treated to resist rot and termites, making it suitable for outdoor use.
What you need to know:
This category includes popular Australian hardwoods like merbau and spotted gum. These are the workhorses of Sydney decking.
Merbau is a dark reddish-brown timber that's naturally durable and termite-resistant. It's widely available and well-priced for a hardwood.
Spotted gum offers beautiful colour variation and excellent durability. It's a bit lighter in colour and has become increasingly popular on the North Shore.
Both options:
Premium options like ironbark and blackbutt offer exceptional durability and beautiful grain patterns.
Ironbark is one of the hardest timbers available, extremely durable, and naturally fire-resistant. It's a popular choice around pools and in bushfire-prone areas.
Blackbutt offers a lighter, more contemporary look with excellent durability and minimal movement.
These timbers cost more upfront but can outlast standard hardwoods and require minimal maintenance over decades.
Composite decking is made from a combination of recycled wood fibres and plastic. It's become increasingly popular for homeowners who want low maintenance.
Mid-tier composite brands offer good durability and a range of colours without the premium price tag.
Benefits:
Considerations:
Brands like Trex, Modwood, and Ekodeck represent the premium end of composite decking.
What you get:
At LikeSilk Building, we find that clients who choose premium composite are typically focused on long-term value and minimal ongoing maintenance rather than lowest upfront cost.
Choose timber if:
Choose composite if:
Even with the same materials, deck costs can vary significantly based on these factors:
Larger decks generally cost less per square metre because setup and mobilisation costs are spread across more area. A simple rectangular deck is also cheaper than complex shapes with angles, curves, or multiple levels.
Budget impact: Complex designs can add 20-30% to your total cost.
If your backyard is only accessible through the house or down a steep slope, material delivery and waste removal become more expensive and time-consuming.
Budget impact: Difficult access can add $2,000 to $5,000+ depending on severity.
Ground-level decks are simpler and cheaper than elevated decks. Once you're building above 1 metre, you'll need more substantial structural support, posts, and bearer systems. You'll also need balustrades for safety.
Budget impact: Elevated decks cost 30-50% more than ground-level equivalents.
If you're replacing an old deck, the condition of the existing subframe matters. Sometimes you can reuse bearers and joists if they're in good condition, which saves significantly. Often, though, rebuilding from scratch is safer and more cost-effective long-term.
Any deck over 1 metre high requires compliant balustrades. Options range from simple timber rails to frameless glass panels.
Typical costs:
If your site needs levelling, drainage solutions, or removal of existing structures, these costs add up quickly.
Budget impact: Can range from a few hundred dollars to $5,000+ for extensive earthworks.
Decks over a certain size or height may require development approval or a complying development certificate from your local council. This adds time and cost to your project. Check the NSW Planning Portal for specific requirements in your area.
Budget impact: $1,500 to $3,000 for documentation and approval fees.
Understanding what's in (and out) of your quote helps you compare builders accurately.
A comprehensive deck quote should cover:
Watch for these common exclusions:
Before accepting a quote:
For more on understanding what to expect during a renovation project, see our guide to budgeting and timelines.
Here's what typical projects cost in Sydney's current market.
New build: Simple rectangular ground-level deck, merbau timber, no balustrades
Cost range: $8,000 to $15,000
This suits a small entertaining area off a kitchen or as a side entry upgrade. Quick build time, minimal disruption.
New build: Elevated deck off living area, spotted gum decking, timber balustrades and stairs
Cost range: $18,000 to $30,000
This is the most common size we build at LikeSilk Building. It creates a genuine outdoor living space that extends your home for entertaining and family life.
New build: Multi-level deck with premium composite, glass balustrades, integrated seating
Cost range: $35,000 to $55,000
These are complete outdoor entertaining areas, often designed alongside full home renovations. They become an extension of the interior living space.
Project: 55m2 pool deck, spotted gum boards on existing frame, includes demo, oiling, and reinstalling glass balustrade
Cost range: $22,000 to $28,000
Re-decking saves significantly when the subframe is still in good condition. Your builder should inspect the frame and advise whether it can be retained or needs replacement.
Pool surrounds require slip-resistant finishes and need to meet specific safety codes for barriers and gates. Expect to pay at the higher end of material costs for appropriate pool-grade timber or composite, plus additional costs for compliant pool fencing integration.
Deck costs vary by state and region, but across Australia you can expect to pay $350 to $950 per square metre for a professionally built new deck. Sydney sits at the higher end of this range due to labour costs and stricter building standards. Regional areas typically cost less, while Melbourne and Sydney are comparable. Re-decking (new boards on an existing frame) is more affordable at $250 to $600 per m2.
A 20x20 deck in feet translates to approximately 37 square metres. Based on current Sydney pricing for a new build, this would cost between $13,000 (basic treated pine) and $35,000 (premium composite) for materials and labour. Most homeowners in this size range choose mid-range hardwood like merbau or spotted gum, putting the typical cost around $20,000 to $28,000.
If you're comparing a DIY build to hiring a professional, DIY will save you labour costs but you'll still pay full retail for materials. A DIY deck might cost 30-40% less than a professional build, but you take on all the risk of structural errors, code compliance issues, and warranty concerns. For anyone without carpentry experience, hiring a qualified builder is the safer investment. Prefabricated deck kits are available but typically only work for basic ground-level projects and still require significant assembly labour.
The 30cm rule refers to the required clearance between the bottom of the deck structure and the ground. This gap allows for airflow, reduces moisture build-up, prevents termite access, and ensures the timber subframe stays dry. Without adequate clearance, your deck subframe will deteriorate much faster, leading to structural issues and costly repairs. This rule is part of the Australian Building Code requirements for deck construction.
Getting a realistic deck quote requires some preparation.
When you contact builders, be ready to share:
You don't need detailed plans at this stage. A good builder can visit your site, discuss your goals, and provide a ballpark estimate before you've spent money on formal designs.
It's sensible to get 2-3 quotes, but be prepared that they may be structured differently. One builder might include everything, another might price the base deck separately from balustrades.
Red flags when comparing quotes:
Look beyond the bottom line number:
The cheapest quote isn't always the best value. You're looking for quality materials, experienced installation, and someone you trust to deliver what they're promising.
Building a deck in Sydney is a significant investment, but it adds valuable outdoor living space and can increase your home's appeal.
Remember:
If you're planning a deck as part of a larger renovation or as a standalone project, we can help you understand what's realistic for your site and budget. At LikeSilk Building, we work with homeowners across Sydney's North Shore to create outdoor spaces that enhance how they live and entertain at home.
Ready to explore what's possible for your deck project? Get in touch for a no-obligation site visit and realistic quote. We'll discuss your goals, explain your options, and give you a clear picture of what to expect.
Thinking about renovating? Even if you're not entirely sure of the scope of your project yet, get in touch with us below with a few details and our licenced builder Cam will reach out to help your get started.
Want more expert insights? Explore these related articles to gain valuable tips and inspiration for your renovation journey.
