Do I need council approval to concrete my backyard?

A plain slab on the ground can often go ahead without building approval, but the council still has a say in what it does to the lot. New concrete sends rain somewhere it was not going before, it takes garden the council may want kept, and it can cover a sewer manhole or change the levels water follows across the yard. Those are the questions to settle before the concreter books the truck, because they are hard to fix once the concrete is down.

What decides it?

Most of it is about water. A slab has to fall away from the house and drain to a pit, a stormwater line or the street, and never across the boundary into the neighbour’s yard. Some councils want the stormwater connection drawn and checked, and a large pour can bring a request for a tank or a soakage pit.

The council also counts the garden. Many councils keep a share of the lot that has to stay open to the ground, and concrete counts against it even though it does not count as site cover, because it has no roof. On a lot with little garden left, a patio slab or a path down the side can be what tips it over. The post on site coverage explains how the roofed part is counted.

And what is underneath. A manhole has to stay open and reachable, never covered, and a slab over a sewer main or an easement needs the asset owner’s say first. In a flood overlay, raising the ground or the slab can need approval of its own, because it pushes water onto other land.

Who decides?

The council decides the planning side: the garden it wants kept, the stormwater and any fill. The water utility decides anything over or near its mains and manholes. Where the slab carries a patio, a shed or a carport, it goes in with that structure’s approval, and the certifier reads it with the rest.

What goes on the site plan?

each pour with its area, and the direction the water falls
where the water ends up: the pit, the stormwater line or the street
the garden left over, with its area
manholes, sewer mains and easements, with the clearance to each
the boundaries and the house, a north point and a scale

Reading it for your own lot

RapidSiteplan reads the lot from its address in a minute, with the boundaries, the house and the existing paths traced from the aerial photo, and the manholes and mains where the water utility publishes them. Trace each pour and the sheet gives its area and its distance to every boundary, so the questions are on paper before anyone mixes concrete. The concreting and driveways page shows the sheet, the post on driveways covers the crossover to the street, and the council pages for every state show what each council maps. Start with the address. The post on overland flow covers how councils map it and what the overlay asks for.

Common questions

Do I need council approval to concrete my backyard? A plain slab on the ground can often go ahead without building approval, but the council still reads where its water goes and how much of the lot stays as garden. A manhole or a sewer main under the pour brings the water utility in, and a slab for a patio, shed or carport goes in with that structure’s approval.