How much does a deck cost in Sydney?

A timber deck in Sydney typically costs between $8,000 and $65,000 depending on size, material, and complexity. A small treated pine deck starts around $8,000–$18,000, while a large composite deck with multiple levels can reach $35,000–$65,000. Factors like site access, height above ground, and council requirements all affect the final price. We recommend getting a free site measure for an accurate written quote.

Do I need council approval for a deck in NSW?

Under NSW planning rules, a deck can be built as exempt development — with no DA or CDC required — if it is no more than 25m² in area, no more than 1m above existing ground level, and located behind the building line. Any deck that exceeds these standards requires either a Complying Development Certificate (CDC) or a full Development Application (DA) to your local council.

How do I know if my builder is licensed in NSW?

In NSW, any building work valued over $5,000 must be carried out by a licensed carpenter/contractor. You can verify any licence at fairtrading.nsw.gov.au using the licence number. MJ Leckie Carpentry holds NSW Contractor Licence 353438C. Always ask for the licence number before signing any contract.

What is the best decking material for coastal Sydney?

For coastal areas like the Northern Beaches, hardwood species such as Spotted Gum and Merbau perform well due to their natural durability and resistance to moisture. Composite decking is also an excellent choice for low maintenance. All fixings should be 316-grade marine stainless steel — standard galvanised fixings corrode rapidly in salt air environments within 1km of the coast.

How long does it take to build a deck?

Most residential decks take between 1 and 3 weeks to complete depending on size and complexity. A simple ground-level deck may be finished in 5–7 working days, while a large elevated deck with stairs and balustrades could take 3–4 weeks. Council approval timelines are separate and can add 2–8 weeks depending on the application type.

What is joist tape and why is it important?

Joist tape is a self-adhesive waterproof membrane applied to the top of deck joists before the decking boards are laid. It prevents water from pooling where screws penetrate the timber — one of the most common causes of premature joist rot in Australian conditions. At MJ Leckie Carpentry, we tape every joist on every deck as a standard inclusion.

How much does a pergola cost in Sydney?

In 2025, the average cost to build a pergola in Sydney ranges from $3,000 for a basic kit structure up to $75,000+ for a large custom insulated roofed pergola. A professionally built timber or steel pergola with a quality roof system typically sits between $15,000–$45,000. Material choice, roofing type, size, and council approval requirements all affect the final cost.

Do pergolas and carports need council approval in NSW?

Under the NSW Exempt Development rules, a pergola or carport can be built without council approval if it does not exceed 25m² in area, is no more than 3m at its highest point, and is located at least 900mm from any side boundary. Any structure exceeding these limits requires a CDC or DA.

How do I get a free quote from MJ Leckie Carpentry?

You can request a free site measure and written quote by calling us on 0482 088 410, emailing admin@mjleckiecarpentry.com.au, or filling out the contact form on this website. We'll arrange a convenient time to visit your property, discuss your project, and provide an accurate quote in writing. There's no obligation and no hard sell.

Project Spotlight: Spotted Gum Deck with Motorised Louvre Pergola — Mosman

Location: Mosman, 2088 NSW
Year: 2024
Materials: Spotted Gum decking, motorised louvre pergola, design pine balustrade, dark capping rail

The Brief: A Year-Round Entertaining Space

This Mosman property sits elevated with northerly aspect and views — a premium entertaining spot that was being underutilised because of weather exposure. The owners wanted to transform it into a space that could be used comfortably in any season: shade in summer, wind protection in autumn and spring, and a sheltered dry zone in winter.

The answer was a motorised louvre pergola — a system that moves with a remote control, adjusting between full shade and full openness.

Spotted Gum Decking

We specified Spotted Gum for this deck — one of Australia's most premium decking timbers:

Durability Class 1 above ground — the highest rating for hardwood decking
Hardness (Janka 13.4) — harder than Merbau, Cumaru, or Blackbutt
Beautiful striped appearance — the distinctive 'spots' and colour variation add visual character
Coastal performance — excellent salt air and humidity resistance
Requires no chemical treatment — the heartwood is naturally durable

Spotted Gum is the choice for premium properties where the deck is seen and used. It's more expensive than other hardwoods, but it looks exceptional and lasts decades with minimal maintenance.

Motorised Louvre Pergola

The motorised louvre system transforms the entertaining experience:

Full close — louvres layer horizontally to create a solid roof
Full open — louvres rotate vertically to create an airy pergola effect
Any angle in between — fine-tune the sun and shade to your preference

The system runs on mains power with a rechargeable remote control. Most users find they adjust it 2-3 times per day depending on sun position and weather.

Design Pine Balustrade with Dark Capping

The balustrade was specified in design pine (a dressed pine with clean lines and detailed molding) rather than the standard baluster-style rail you see on most decks. Design pine balustrades are higher cost but look significantly more refined.

The dark capping rail — matched to the colour of the house trim — ties the deck visually back to the home rather than making it feel like an add-on.

Large Posts for Visual Weight

140mm posts were specified rather than the standard 100mm. On an elevated deck with significant visual presence, larger posts look proportional and substantial. It's a detail that costs nothing and changes how the whole structure is perceived.

The Result

An elevated entertaining space that looks and functions at the same level as the home. The motorised louvres mean the owners are using it in all seasons now — something they wouldn't have done with a standard fixed pergola.

We Work Extensively in Mosman

Mosman is one of our most active project areas. We've completed decks, pergolas, and full outdoor living spaces throughout the suburb — both on the harbour-facing side and the bushland side. We understand Mosman's specific conditions: steep terrain, sandstone foundations, proximity to water, and the premium standards expected in the area.

If you're planning an elevated deck or outdoor space in Mosman or the surrounding Northern Beaches, contact us for a consultation.

Call us on 0468 093 569 or get a free quote.

MJ Leckie Carpentry — Licensed Carpenters, Lic 353438C

Project Spotlight: Spotted Gum Deck with Motorised Louvre Pergola — Mosman

Project Spotlight: Spotted Gum Deck with Motorised Louvre Pergola — Mosman

The Brief: A Year-Round Entertaining Space

Spotted Gum Decking

Motorised Louvre Pergola

Design Pine Balustrade with Dark Capping

Large Posts for Visual Weight

The Result

We Work Extensively in Mosman

Ready to start a similar project?

Ready to Start Your Outdoor Project?