Flat Patios Armadale

Harrisdale and Piara Waters went up quickly on the plain, mostly since 2010. Small lots, two-storey homes, an alfresco already built in, and a rectangle of yard between it and the fence.

Armadale proper, Kelmscott, Seville Grove and Camillo are the established middle. Largely postwar through to 1990s brick and tile on regular blocks with usable back yards.

Then the ground stands up. Mount Nasura, Mount Richon, Bedfordale and Roleystone climb the scarp on big treed lots where the driveway is often steeper than the street.

Forrestdale sits apart from all of it. Larger lots on flat ground near the lake, several of them semi-rural, with room to put a patio well away from the house if that is how the block gets used.

The newer estates carry developer design guidelines registered against the title, and they can be specific. Roof material, colour, street visibility and how a structure relates to the front elevation are all fair game.

That obligation is private and sits beside the council permit rather than replacing it. The City of Armadale does not enforce it, and a fully compliant patio can still breach it.

It is a five minute check that occasionally changes the whole design. Worth doing before anything is ordered.

The flat suburbs sit on reactive clay soil that swells and shrinks with the seasons. Footings are designed against the site classification, and soakwells are sized knowing the ground drains slowly.

The hills suburbs are a different material entirely. Lateritic gravel, clay and granite, with rock that can appear anywhere from the surface down, and drainage that varies over a few metres.

Two halves, one council, two completely different footing conversations. It is the main reason a phone quote here is not worth much.

Kelmscott sits right on the join. Parts of it behave like the plain and parts like the foothills, and the change can happen inside a couple of streets.

Roleystone, Bedfordale, Mount Nasura, Mount Richon and Karragullen sit in designated bushfire prone areas. Anyone who was here in 2011 remembers why that designation exists.

Where the mapping applies, a patio attached to or close to the house is drawn into the bushfire construction requirements at the level assessed for the site.

Steel is the right material for it. A Colorbond roof on a steel frame is non-combustible, and the work goes into ember detailing: gutter guard, closed gaps, and non-combustible flashing at the house.

Hills blocks in this council are frequently terraced, with the house on one level and the yard cut and filled around it. Retaining walls and their setbacks then dictate where a footing can safely go.

A footing too close to the top of a retaining wall loads ground that was never designed to carry it. That gets checked rather than assumed, and sometimes the post moves and the beam grows.

The roof plane stays flat regardless. What varies is post length, and on a terraced yard that variation is what makes the finished structure look intentional instead of improvised.

A patio is a Class 10a structure, so the City of Armadale requires a building permit before construction. Site plan, elevations, structural engineering for the wind classification, and a stormwater design suited to the ground.

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 attached.

On the plain the extra question is usually the R-Codes. Setbacks, open space and the outdoor living area decide whether development approval is needed on the smaller estate lots.

In the hills the extra question is bushfire. Where the address is mapped, the construction standard follows the assessed rating, and depending on the proposal an assessment may need to go in with the application.

On the scarp the house above you sees the top of your patio rather than the underside. The roof becomes part of the view from someone else's living room, and part of yours from the level above the yard.

Colour does the heavy lifting. A darker, low-reflectance Colorbond settles into a treed hills block, where a bright pale sheet sits in the middle of it looking like a tarp.

Heat pulls the other way, and that is the trade. An insulated panel lets you take a darker colour on top without the underside becoming unbearable in February.