Do I need council approval for a retaining wall?

The single question that decides how a retaining wall job runs is the height. Under a metre is one thing. Over a metre is another, because that is where an engineer and the council come in. Here is the plain version of how the over-a-metre line works in South Australia, so nothing catches you out.

The short answer

In South Australia, a wall that retains a metre or less of ground usually does not need development approval. Once it holds back more than a metre, it normally does. The same is true if the wall carries a surcharge, that is, a load above it like a driveway, a shed or a building. At that point the wall needs a structural engineer’s design and council development approval before any work starts.

What the over-a-metre line actually triggers

• A structural design. An engineer sizes the wall, the footing and the reinforcement to the height, the soil and any load above it, built to AS 4678.
• Engineer certification. The engineer signs off that the design is sound. That certification goes in with the application.
• Council development approval. The council assesses and consents to the work before it begins. This adds lead time, so it pays to start early.
• The combined height. A barrier on top of the wall can add to the retained height and push the whole thing over the line. The numbers stack.

The cheap quote that never mentions the engineer or the council is not saving you money. It is leaving out the step that makes a tall wall on a slope safe and legal. That is the most expensive thing to skip.

Who certifies it, and why it matters

A wall over a metre that fails on a slope can take the ground, and what sits on it, with it. That is why the engineer is not optional. The engineer designs to the real loads. The sign-off proves the design. The council approval puts it on the record. We manage the whole chain for you, so you are not left chasing the council yourself.

Not sure how high your wall is?

Tell us the height drop on the estimator and it will flag whether you are likely over the metre that triggers the engineering and approval. Then book a free site assessment and we will measure the fall on the slope and confirm it, before anything is committed. This is general guidance, not a planning ruling. The council has the final say on your block.