How Much Does a Deck Cost in Sydney? Real 2026 Price Ranges

A deck is usually the single most-used surface in a Sydney backyard — and the one homeowners most often underestimate the cost of. The number that matters isn't the timber price at Bunnings; it's the finished, engineered, code-compliant deck standing in your yard. Here's what those actually cost in 2026, based on the projects we quote every week across Sydney and the Sutherland Shire.

A straightforward ground-level deck in spotted gum or blackbutt — the two workhorses of Sydney decking — runs $450 to $700 per square metre installed. That includes a treated pine sub-frame on concrete footings, stainless fixings, and an oiled finish. A 25m² entertaining deck therefore lands between $11,000 and $17,500.

What moves you up or down that range? Board width and grade (standard vs. select), the complexity of the perimeter (a rectangle is cheap; curves and picture-framing are not), and whether the sub-frame is sitting on flat ground or navigating a slope.

The moment a deck goes above 600mm, it needs engineered footings, balustrades, and often a structural engineer's certificate. Budget $800 to $1,200 per square metre for elevated hardwood work. A 30m² first-floor deck with stairs and a compliant balustrade is realistically a $25,000 to $40,000 job.

Council approval is likely once the deck is attached to a dwelling and above certain heights — factor $2,000 to $5,000 and 6–10 weeks for a Complying Development Certificate.

Modern composites (capped WPC boards from the better brands) install for a similar price to mid-grade hardwood — $500 to $750 per square metre once the sub-frame is done right. The saving isn't up-front; it's the decade of oiling you don't do.

Where composite wins: shaded, damp, poolside, or rental properties. Where hardwood still wins: the look and feel of real timber under bare feet, and the ability to sand and refinish in year fifteen.

Watch for these missing lines: engineered footings (not just pavers on dirt), stainless or hot-dip galvanised fixings (galv nails rust out in the Sydney's salt air), sub-frame protection tape over joists, drainage under the deck, and a proper oil or seal on day one. Any of these missing turns a 20-year deck into an 8-year deck.

For most Sydney and Sutherland Shire homes, a properly built entertaining deck sits between $15,000 and $35,000 all-in. Anyone quoting dramatically below that on a comparable spec is cutting something you'll see later. We're happy to walk your site and give you a fixed, itemised number — no obligation.