Do I Need an Engineer for My Retaining Wall in Adelaide?

When you’re building a retaining wall in Adelaide, one of the first questions that often comes up is:

“Do I need an engineer?”

If you’re asking that question, the answer is probably yes.

A retaining wall that isn’t built to engineering standards can fail — and that can mean injury, property damage, soil erosion, and costly repairs. Understanding the regulations and when engineering is required will help you build safely, legally, and for the long term.

Retaining Wall Height Rules in Adelaide

Council regulations vary across Australia, but in South Australia:

• Any retaining wall over 1,000 mm (1 metre) in height requires council approval.

• In other states, the limit may be 600 mm, but all states require engineering design for any wall needing council approval.

• The higher the wall, the greater the risk — and the greater the need for engineering expertise.

Even for DIY projects, it’s essential to check with your local council before starting.

Key Safety & Impact Questions

Before building your retaining wall, ask yourself:

• If the wall collapsed, would it injure anyone?

• Could it damage nearby property or cause soil erosion?

• Would it affect neighbouring properties?

• Would it cause water runoff issues onto someone else’s land?

If the answer to any of these is “yes” — you need to take extra care with design, engineering, and approvals.

Boundary & Easement Considerations

The location of your retaining wall matters just as much as the height:

• Walls on or near boundaries may require council approval no matter the height.

• In SA, most councils require approval for a combined wall + fence height over 2.1 m.

• Building over an easement (e.g., SA Water) requires written consent from the easement owner.

• Walls must be set back at least 1 metre from sewerage pipes or water mains.

• No wall can be designed in a way that causes water to flow onto a neighbour’s property.

What If My Wall Is Under the Height Limit?

If your retaining wall is under 1 metre in Adelaide, you may not need an engineer.However:

• Some councils have stricter limits (e.g., 600 mm or 800 mm).

• Restrictions may still apply depending on slope, soil type, location, or drainage impact.

• An engineer can still be valuable to ensure structural safety and avoid future issues.

Why Work With Square Gardens?

At Square Gardens, we work with trusted Adelaide engineers every day. We can arrange:

• Full engineering design and certification

• Council approval submissions and liaison

• Site assessments to check for easements, drainage, and compliance risks

Even if you’re not sure whether your wall needs engineering, we’ll guide you through the process so you can build with confidence.

📞 Call Square Gardens today on 0425 015 911 for expert retaining wall advice, engineering referrals, and council approval support.