A new timber deck on the Mornington Peninsula usually costs $275 to $505 per square metre installed in 2026, depending on the timber. Composite boards run higher, at around $580 per square metre. A typical 25 m² hardwood deck lands between $11,000 and $16,500 once you add stairs and a balustrade.
This guide breaks down where the money goes: timber choice, deck height, stairs and railings, permits, and the things that push prices up near the coast. It’s written by Belle Carpentry, a local carpenter building and restoring decks from Mount Eliza to Portsea.
These are installed prices, including labour, subframe, decking boards and GST, for a standard ground-level deck.
| Decking material | Typical price per m² | Usual range | Good to know |
|---|---|---|---|
| Treated pine | $275 | $190–$370 | Cheapest. Needs regular oiling and suits sheltered spots more than exposed coastal ones. |
| Merbau | $440 | $315–$580 | Popular hardwood with a rich red colour. Bleeds tannin for the first few months. |
| Blackbutt | $470 | $345–$650 | Pale Australian hardwood. Often chosen for bushfire-prone blocks. |
| Spotted gum | $505 | $370–$630 | Very hard and durable. A favourite for coastal and bushfire-prone homes. |
| Composite (standard) | $580 | $295–$735 | Low maintenance and no oiling. Premium capped boards can reach $945 per m². |
Source: independent Melbourne decking prices, updated October 2026 (whatsthedamage.com.au).
Want to see the boards themselves? Browse our decking board collection.
Here’s the typical installed price for common deck sizes, before stairs, railings or demolition.
| Material | Small (15 m²) | Medium (25 m²) | Large (40 m²) |
|---|---|---|---|
| Treated pine | $4,125 | $6,875 | $11,000 |
| Merbau | $6,600 | $11,000 | $17,600 |
| Blackbutt | $7,050 | $11,750 | $18,800 |
| Spotted gum | $7,575 | $12,625 | $20,200 |
| Composite (standard) | $8,700 | $14,500 | $23,200 |
A 20 m² ground-level merbau deck at about $8,800, plus removing the old deck (about $740).
A 25 m² spotted gum deck at about $12,600, one flight of stairs down to the garden (about $2,100), and 6 metres of balustrade (about $1,800).
A 30 m² composite deck at about $17,400, an elevation allowance for the taller subframe (about $3,150), stairs (about $2,100) and 10 metres of balustrade (about $2,950).
| Extra | Typical cost |
|---|---|
| Stairs (one flight) | $1,050–$4,725 (typically $2,100) |
| Single deck steps | $190–$420 per step |
| Balustrade or railing | $160–$470 per metre (typically $295) |
| Raised deck on a slope | add $52–$190 per m² |
| Removing an old deck | $21–$58 per m² |
| Pergola over the deck | $5,250–$15,750 |
| Sanding and oiling (existing deck) | $26–$63 per m² |
In Victoria, a deck attached to your house or pool needs a building permit, whatever its size. Detached decks usually need one too. Raised decks may also need engineering, and in some cases a planning permit, which adds cost and a few weeks to the timeline. Check with a building surveyor before work starts. A good builder will organise this for you.
For any job worth more than $10,000 (labour, materials and GST combined), Victorian law requires a registered builder. Always ask for the registration number on your quote.
Sources: Victorian Building Authority, Practice Note BP-01; Building and Plumbing Commission, “Engaging a builder”.
Most ground-level decks up to about 30 m² take 1 to 2 weeks on site. Raised decks, decks with stairs and balustrades, or jobs waiting on a permit take longer. Allow extra time over summer, when builders are busiest.
Every deck project is different, so the best way to get an accurate price is a free measure and quote on site. As a local Mornington Peninsula decking company and custom deck builder, we price everything from a simple backyard deck or broad front steps to a wrap-around verandah deck, a curved spotted gum deck or a raised composite deck with glass balustrade. We build with premium composite boards from NexGEN composite decking as well as hardwood and treated pine, across Mount Eliza, Mount Martha, Somers, McCrae, Portsea and Sorrento. Book your free deck quote.
Treated pine, at around $190–$370 per m² installed. It needs oiling every year or so to last, especially near the coast.
Composite costs more up front but needs no oiling. Over 10–15 years, the money saved on maintenance often closes much of the gap with hardwood.
Spotted gum and blackbutt are hard, durable and suited to many bushfire-rated sites. Merbau is a popular, slightly cheaper alternative. Whatever you choose, use stainless steel fixings near the water.
Yes. Belle Carpentry gives free, itemised deck quotes across the Mornington Peninsula, so you can see exactly where the money goes.
Every block on the Peninsula is different, so the best way to know your real cost is a site visit. See our deck building service or call 0434 088 829 for a free, itemised quote.