Deck and pergola rules, materials and lifespan

Updated 19 Aug 2026/9 min read/By Manttan Construction · QBCC 15030266

Queensland residential decks, pergolas and patios

1 m	Height above natural ground at which a deck normally moves into building approval territory.
10 m²	Common upper size limit for an exempt unroofed structure.
5 m	Maximum length of any one side under the usual exemption.
1.5 m	Typical minimum side and rear boundary setback for structures up to 4.5 m high; 2.0 m up to 7.5 m high.
Roofed	Adding a roof generally removes the exemption — treat roofed patios, verandahs and carports as needing approval.
Barriers	A compliant barrier is required where there is a drop of more than 1 m; your certifier confirms the height and opening limits.
$3,300	Above this value, including labour, materials and GST, the deck must be built by a QBCC-licensed contractor.

01 — Approvals

When does a deck or pergola need approval?

The exemption is a package — a deck must satisfy every criterion, not most of them. Assume approval is needed if any of the following is true:

• Any part of the finished deck is more than 1 m above natural ground level.
• The deck is larger than about 10 m² or has a side longer than 5 m.
• It is attached to the house, or roofed, or later gets roofed.
• It sits inside an overlay — flood, coastal hazard, bushfire, character or vegetation.
• It is close to a boundary, over an easement, or over sewer or council assets.
• It forms part of a pool barrier, in which case pool safety rules also apply.

Our approvals guide covers the planning versus building distinction in more detail; if the deck touches a pool, read the pool fencing guide too.

02 — Structure

What holds a deck up, and what makes one feel solid?

Bounce and creak are design problems, not timber problems. Three things fix them: footings sized for the actual soil, bearer and joist spans inside the span tables for the species and grade, and proper bracing where the deck is elevated.

• Footings. Concrete piers sized from a soil classification, dug to depth — not pavers on grade.
• Posts and bearers. Correctly sized, with galvanised or stainless fixings rated for coastal exposure.
• Joist spacing. Tighter spacing for thinner or composite boards; the board manufacturer dictates the maximum.
• Ventilation and drainage. Air movement under the deck and water directed away from the house is what stops rot and termite pressure.
• Flashing at the house. Where a deck meets the wall, flashing and a drainage gap keep water out of the frame.

03 — Materials

Hardwood, treated pine or composite?

Australian hardwood

Best looking, hardest wearing, highest resale appeal. Needs oiling every year or two to hold colour, or it silvers off. Dense species are unforgiving of poor fixing detail.

Treated pine

Cheapest to build, easy to work, fine when painted or stained and maintained. Softer underfoot and more prone to surface checking in full sun.

Composite

No oiling, stable colour, splinter free — good for pool surrounds and busy families. Higher upfront cost, gets hotter in direct summer sun, and joist spacing and expansion gaps must follow the manufacturer exactly or it moves.

For a shaded or covered deck, hardwood is usually the better buy. For a west-facing pool surround with no shade and small kids, composite earns its premium.

04 — Cover

Pergola, patio roof or insulated panel?

A pergola with battens gives dappled shade and keeps the exemption conversation simpler. A solid patio roof makes the space usable in a Queensland downpour but is building work, and it changes how much light reaches the rooms behind it.

Insulated roof panels cost more but cut radiant heat noticeably and let you run a ceiling fan and lights inside the panel. Whatever the roof, get the fall, gutter and downpipe connection designed — most patio roof complaints are actually drainage complaints.

05 — Lifespan

What maintenance does a deck really need?

• Every 6 months. Clear leaves and debris from between boards and under the deck; check drainage still runs away from the house.
• Every 12–24 months. Clean and re-oil hardwood, or re-coat stained pine. Sooner on full-sun faces.
• Annually. Check fixings, balustrade rigidity, and the connection back to the house.
• Every few years. Inspect posts at ground level and any timber in contact with soil — that is where failure starts.

A well-built hardwood deck that gets oiled will outlast several sets of outdoor furniture. One that never gets cleaned traps moisture between the boards and rots from the top down.

Questions

Decks FAQ

Still unsure how it applies to your place? Call 0402 847 873 and we will tell you straight.

Do I need approval for a deck under 1 metre high?+

Often not — if it is also under about 10 square metres, has no side longer than 5 metres, is unroofed and is not attached to the house. Every criterion has to be met, and overlays or a cyclonic wind region can remove the exemption.

How far from the boundary can I build a deck?+

Typically at least 1.5 metres for structures up to 4.5 metres high, and 2 metres up to 7.5 metres, but the Queensland Development Code and your local planning scheme govern it. Reduced setbacks are sometimes possible with council agreement.

Is composite decking better than hardwood?+

It is better for low maintenance, pool surrounds and splinter-free family use. Hardwood looks better, feels cooler in direct sun and adds more to resale, but needs oiling every year or two.

How long does a deck take to build?+

A straightforward ground-level deck is usually a week or so on site. An elevated deck with engineering, approvals and a roof runs longer — the approval lead time is often the biggest variable, which is why we start it early.

Decks & pergolas→ Council approvals explained→ Pool fencing compliance→ All guides→

Get advice & a quote → 0402 847 873