Do I Need Council Approval for a Retaining Wall in South Australia?

Short answer: in South Australia, a retaining wall generally needs development approval if it retains more than 1 metre, and can need it at lower heights depending on where it sits and what it supports. Here's the practical version of the rules under the Planning, Development and Infrastructure Act (PDI Act) framework.

When approval is generally NOT required

A retaining wall is typically exempt development when all of these hold:

• It retains 1 metre or less difference in ground level;
• It doesn't support a building, structure or driveway (no surcharge);
• It isn't in a special zone or overlay that removes exemptions (heritage areas, some hills-face and flood overlays);
• Any fence on top keeps the combined structure within the fencing rules for your zone.

Most low garden walls and terracing under a metre fall here — build away, but build properly.

When you DO need approval

• Retained height over 1 metre. This is the big one, and it's measured as the difference in finished ground levels, not the height of the materials.
• Wall + surcharge. A wall of any height supporting a driveway, shed, pool or structure will generally need assessment because the loads change the engineering.
• Close to boundaries with height. Walls near boundaries interact with fencing height rules; a 900 mm wall with a 1.8 m fence on top is a 2.7 m structure to your neighbour, and councils treat it accordingly.
• Special overlays. Hills Face Zone, heritage areas, watercourse and flooding overlays each have their own triggers — Stirling and Mitcham hills properties hit these often.

Applications go through SA's PlanSA portal, usually with site plans, elevations and an engineer's design for the wall. Allow 4–8 weeks for straightforward consents.

The neighbour question

If the wall sits on or near a shared boundary, talk early. Retaining walls aren't automatically "fencing work" under the Fences Act 1975 (SA) — the general principle is that the party who benefits from (or caused) the change in ground level bears the cost of retaining it. If your excavation or fill created the level difference, expect the wall to be yours.

Building without approval

Councils can require unapproved development to be removed or retrospectively approved, and an unapproved structural wall becomes a genuine problem at sale time — conveyancers ask. Retrospective approval costs more than doing it once, properly, in order.

How we handle it

We assess approval triggers during quoting, prepare the engineering and PlanSA documentation when required, and don't start regulated work without consent in hand. It protects the project — and it means the wall on your title is an asset, not a liability. Talk to us about your wall.