Complete Guide to Building a Deck or Pergola in 2026
Everything you need to know about building a deck or pergola in Australia — materials, costs, council permits, and how to choose the right builder. Real pricing from 2026.
A deck or pergola is one of the best investments you can make in your outdoor living space. In Australia’s climate, a well-built deck extends your usable living area for 8–10 months of the year. But the costs can vary enormously depending on materials, size, and design complexity.
This guide covers everything: materials comparison, real 2026 pricing, council permit requirements, and tips for getting the best value from your builder.
Deck Building Costs in 2026
| Deck Type | Cost per m² | 20m² Deck | 40m² Deck |
|---|---|---|---|
| Treated pine | $180–$320 | $3,600–$6,400 | $7,200–$12,800 |
| Hardwood (merbau, spotted gum) | $350–$600 | $7,000–$12,000 | $14,000–$24,000 |
| Composite (Trex, ModWood) | $400–$700 | $8,000–$14,000 | $16,000–$28,000 |
| Elevated deck (1m+ off ground) | $500–$900 | $10,000–$18,000 | $20,000–$36,000 |
Prices include labour, materials, and basic balustrade where required. 2026 national averages.
Pergola Costs in 2026
| Pergola Type | 3m × 3m | 4m × 6m | 6m × 6m |
|---|---|---|---|
| Treated pine (flat roof) | $3,000–$5,000 | $5,500–$9,000 | $8,000–$14,000 |
| Steel frame + colorbond | $5,000–$8,000 | $8,000–$14,000 | $12,000–$22,000 |
| Hardwood (open rafters) | $4,500–$7,500 | $7,500–$12,000 | $11,000–$18,000 |
| Opening louvre roof | $8,000–$15,000 | $15,000–$28,000 | $25,000–$45,000 |
Choosing Your Decking Material
Treated Pine
The most affordable option. H3-treated pine is suitable for above-ground decking and is widely available. It’s easy to work with and takes stain well. The downsides: it requires re-staining every 1–2 years, can warp and split, and typically lasts 15–20 years with proper maintenance.
Best for: Budget-conscious builds, covered areas, rental properties
Hardwood
Australian hardwoods like merbau, spotted gum, blackbutt, and jarrah are beautiful, durable, and naturally resistant to termites and rot. They last 25–40+ years and develop a stunning silver-grey patina if left to weather naturally. The trade-off is higher cost and more difficulty in construction (hardwoods require pre-drilling for every screw).
Best for: Long-term family homes, high-traffic areas, natural aesthetic
Composite Decking
Made from recycled wood fibres and plastic, composite boards (brands like Trex, ModWood, Ekodeck) offer low maintenance and consistent colour. They won’t splinter, warp, or need staining. The initial cost is higher than timber, but you save on maintenance over 20+ years.
Best for: Low-maintenance requirements, pool surrounds, modern aesthetic
What’s Included in a Deck Quote?
A thorough deck building quote should include:
- Site preparation: Clearing, levelling, and any excavation needed
- Footings: Concrete stumps or piers (critical for structural integrity)
- Frame: Bearers and joists (usually treated pine or steel)
- Decking boards: Your chosen material, including wastage allowance
- Fixings: Stainless steel screws (essential for hardwood and coastal areas)
- Balustrade: Required by code if the deck is 1m+ above ground level
- Steps: If the deck is elevated
- Finishing: Oil, stain, or sealer application
Watch out for quotes that exclude footings, balustrade, or site prep — these are significant costs that add $2,000–$8,000.
Council Permits & Regulations
In most Australian states, you need council approval (a Development Application or Complying Development Certificate) for decks and pergolas. The rules vary by state:
NSW
Decks under 600mm high and under 20m² are typically exempt development. Above that, you need a Complying Development Certificate (CDC) at minimum. Pergolas attached to the house usually require approval.
Victoria
Decks within 1m of ground level are generally permit-exempt. Pergolas under 20m² with no enclosed walls may be exempt. Always check with your local council as overlays and heritage zones can change requirements.
Queensland
Decks more than 1m above natural ground level need building approval. Roofed structures (pergolas with roofing) that exceed 10m² typically require approval.
South Australia
Decks under 500mm high are generally exempt. Pergolas and verandahs under 15m² may be exempt. Properties in heritage areas, bushfire zones, or flood zones have additional requirements.
Permit costs typically range from $200–$1,500 depending on your council and the complexity of the application. Many deck builders will handle the permit process for you for an additional fee of $500–$1,000.
Foundation & Footing Options
Your deck’s longevity depends on proper footings. The main options:
Concrete Piers
The most common and reliable option. Holes are bored 450–600mm deep, filled with concrete, and fitted with galvanised stirrups. Cost: $50–$120 per pier. A standard deck needs 8–16 piers depending on size.
Screw Piles
Steel helical piles screwed into the ground. Faster to install and suitable for reactive clay soils. Cost: $80–$180 per pile. Increasingly popular for their speed and reliability.
Concrete Slab
For ground-level decks, a concrete slab with the deck built on top provides a stable, termite-resistant base. This adds $60–$100 per m² but gives the most solid foundation. Often combined with professional concreting.
Integrating with Other Outdoor Features
A deck or pergola often triggers other improvements:
- Fencing: Privacy screens or boundary fencing to complement your new outdoor area ($70–$200 per metre)
- Painting & Staining: Matching your deck stain with exterior house painting creates a cohesive look
- Concreting: Pathways and adjoining concrete areas for a finished landscape
- Lighting: Deck lighting by a licensed electrician extends usability into the evening ($500–$2,000)
How to Choose the Right Deck Builder
Check licensing
In all states, a builder constructing a deck over certain value thresholds needs a Builder’s Licence or equivalent registration. In NSW, any work over $5,000 requires a licensed builder. In Victoria, it’s over $10,000. Always verify their licence number on your state’s consumer affairs website.
Ask for recent examples
A good deck builder should have photos and addresses of recent work they’re happy for you to inspect. Drive by a few completed decks to check the quality of finishing details — how neat are the cuts? Are the board gaps consistent? Does the balustrade look solid?
Get itemised quotes
Lump-sum quotes hide costs. Insist on a breakdown showing materials, labour, footings, balustrade, permits, and site prep separately. This makes it easier to compare quotes and identify where one builder may be cutting corners.
Check insurance
Your builder should have public liability insurance ($5–$20 million) and, for larger projects, home warranty insurance. Ask for certificates, not just assurances.
Maintenance: Keeping Your Deck in Great Shape
Timber decks
- Oil or stain every 12–18 months (cost: $200–$600 for materials, $400–$1,200 if professionally done)
- Pressure wash annually (or hire for $150–$300)
- Check fixings annually — tighten or replace any that have worked loose
- Address any cupping, splitting, or loose boards promptly
Composite decks
- Wash with soapy water twice a year
- No staining or sealing required
- Remove debris from between boards to prevent moisture buildup
- Most composites come with 25-year warranties on structural integrity and fade resistance
Frequently Asked Questions
Do I need a permit to build a deck?
It depends on the deck height, size, and your location. Low-level decks (under 500–600mm above ground) are often exempt, but always confirm with your local council before starting.
How long does it take to build a deck?
A standard 20–30m² deck takes 3–7 days to build once materials are on site. Elevated decks with complex balustrades may take 2–3 weeks. Concrete footings need 7 days to cure before building starts.
Is composite decking worth the extra cost?
Over 15–20 years, composite often works out cheaper than hardwood when you factor in annual oiling, sanding, and potential board replacement. If you value low maintenance, composite is an excellent choice.
What’s the best timber for an Australian deck?
Spotted gum and blackbutt are the most popular Australian hardwoods — they’re BAL-rated for bushfire zones, naturally termite-resistant, and look beautiful. Merbau is a popular imported alternative that’s slightly cheaper but can leach tannin stains.
Can I build a deck myself?
Small, low-level decks (under 600mm, under 10m²) can be DIY projects if you have carpentry skills. Anything elevated, attached to the house, or requiring balustrades should be done by a licensed builder for safety and code compliance.
How We Collect These Prices
Our pricing data comes from real quotes provided by licensed deck builders across Australia. We survey builders in all capital cities and major regional centres, updating our data quarterly.
For related projects:
- Concreting costs (paths, footings, outdoor areas)
- Fencing costs (privacy screens, boundary fencing)
- Painting costs (exterior painting and deck staining)
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