Flat Roof Patios in Stirling

Along the coast at Trigg, North Beach and Watermans Bay you get a mix of surviving 1970s brick homes and heavily rebuilt modern houses, often two or three storeys chasing a view.

The middle ring is postwar. Innaloo, Doubleview, Tuart Hill, Balcatta, Osborne Park and Yokine are dominated by 1950s and 60s brick and tile on generous lots, with low fascias and shallow eaves.

Then the south east. Mount Lawley, Inglewood, Menora and Coolbinia carry Federation and interwar housing, with the character controls that come with it. Karrinyup, Carine, Gwelup and Hamersley sit somewhere between, mostly 1970s and 80s on larger blocks.

A rear survey-strata lot reached by a battleaxe driveway is a common Stirling situation, and it reshapes the patio brief. The usable yard is often a strip rather than a square, and the access for materials is a driveway barely wider than a car.

Posts become the design problem. On a four-metre-wide courtyard there is no room for an intermediate post, so the beam has to carry the whole span, and it has to do it without gaining so much depth that it eats the headroom.

This is where a flat roof earns its place. A single plane at a shallow fall keeps the finished height low, so you clear the boundary rules and the neighbour's sightlines while still standing up straight underneath it.

Parts of Mount Lawley, Inglewood, Menora and Coolbinia sit inside character or heritage protection precincts administered by the City of Stirling. The intent is to keep the streetscape reading as it did when it was built.

For a rear patio that is usually manageable. Controls concentrate on what the street can see, and a flat roof behind the house, below the main roofline, is generally the least contentious structure you can put there.

It still pays to check the property first. If the dwelling is on a heritage list in its own right, or the patio would be visible from a public street, the planning conversation happens before the building permit rather than after it.

Along the coastal ridge the ground is Spearwood sand over limestone, and the limestone can be close enough to the surface that a footing hole turns into a coring job.

Inland toward Balga, Nollamara and Mirrabooka you are into the grey Bassendean sands. Deep, loose, fast draining, and short on the lateral support a patio post wants.

Around Herdsman Lake and Lake Gwelup it changes again. Old wetland margins can bring damp, organic ground and a high seasonal water table, which affects both the footing design and how well a soakwell will actually clear.

A patio needs a building permit from the City of Stirling before work starts, because it is a Class 10a structure under the National Construction Code. The application carries a site plan, elevations, engineering for the assessed wind classification and the stormwater detail.

Class 10a applications can be lodged uncertified for the council to assess, or certified with a certificate of design compliance from a registered building surveyor already attached.

On infill lots the R-Codes questions arrive first. Boundary setback, the proportion of the site left as open space, and whether the required outdoor living area remains uncovered are what decide whether you also need development approval.

Postwar Stirling houses have low fascias, and that is the constraint people underestimate. You need enough height under the new roof to stand comfortably, enough fall to move water, and a fixing point that does not sit above the existing gutter.

There are three usual answers. Fix below the gutter with a receiver flashing, cut in and tie above the gutter line, or run the patio as a freestanding structure a few hundred millimetres clear of the house.

Freestanding is underrated on these houses. It avoids touching a tiled roof altogether, sidesteps the flashing risk, and lets the patio sit at whatever height suits the yard rather than whatever height the 1962 builder chose.

The tiles themselves often settle the argument. Roofs of that era were frequently laid on battens without sarking, so cutting in above the gutter opens up more than anyone wants. Where the tiles have gone brittle, freestanding stops being an alternative and becomes the recommendation.