Building a patio: choosing a roof and getting it approved
Flat, gable and insulated roofs compared, why the slab underneath matters, and who should handle council approval.
A patio is the cheapest way to turn an exposed backyard into a room you can use for most of the year — shade in summer, shelter from a shower, somewhere to put the table. Priced per square metre installed, it's a project where a few early decisions shape both the cost and how usable the space ends up being.
The two questions that matter most are what's overhead and what's underfoot: the roof type sets the character and the price, and whether there's already a slab decides how much groundwork you're paying for.
What the job involves
Patios are priced per square metre installed, covering the posts, frame, roofing and attachment to the house. A flat (skillion) roof in steel is the most affordable configuration. Gable roofs add height and presence for more money. Insulated roof panels cost more again but keep the space cooler in summer and let you mount lights and fans neatly into the panel.
What's underneath matters just as much. If there's no existing slab or paving, a new concrete slab adds meaningfully to the budget — sometimes several thousand dollars — so knowing whether you're building over an existing surface changes the number a lot. Freestanding structures and raised attachment points need more engineering than a simple attached skillion.
Most patios need council approval or private certification, which is a modest but real extra cost, and connecting the patio roof properly to your stormwater is essential — pooling runoff is the most common patio defect.
How the cost works
A modest flat-roof steel patio over an existing slab sits at the bottom of the range, a gable patio with extra height and connected gutters lands in the middle, and a large insulated-panel patio with lighting, fans and a new slab reaches the top. The estimate on this page adjusts for size, roof type and whether a slab is needed, so treat any figure as a guide.
Footprint is the baseline because it's priced per square metre, and the roof style and the slab are the two levers that pull quotes apart. A gable or insulated roof adds a clear premium over skillion, and a new slab adds a chunk over building on existing paving. Confirm which you're comparing, and check whether approval is inside the quote, because a suspiciously cheap patio sometimes leaves the certification for you to sort.
Choosing the right patio builder
A patio is building work, and whether it needs a licensed builder depends on your state and the value — check your state's building authority, and verify the licence and ABN where one applies. The bigger practical question is approval: reputable patio companies usually include council or private certification in their service, so confirm who's handling it rather than assuming.
Ask specifically how the patio roof connects to your stormwater, because a roof that dumps runoff at the base of the posts or against the house is the classic patio failure. If you can stretch to insulated roof panels, they make the space genuinely usable through summer and let lights and fans mount cleanly — a difference you feel every hot afternoon.
Mistakes to avoid
Patio regrets are usually about approvals, drainage, or underestimating the slab.
- Assuming the quote includes council approval when the certification is left to you
- Forgetting a new slab adds thousands if there's no existing surface to build on
- Not confirming how the roof connects to stormwater, then living with pooling runoff
- Comparing a skillion quote against a gable or insulated one as if they're equivalent
- Skipping the builder's licence check where your state requires one for the value
- Choosing a cheap roof, then finding the space is unusable in summer heat
Indicative range only, not a quote — see the full guide for worked scenarios and what moves the price.
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