Can a retaining wall be built without an engineer?

For low retaining walls below a specific height threshold (generally around 700mm-1m depending on site conditions and what the wall retains), engineering certification often isn’t required. Above that threshold, or where the wall supports a surcharge load like a driveway or structure, formal engineering design becomes genuinely necessary.

Even where certification isn’t strictly required, sound construction practice — proper footings, drainage, and appropriate materials for the height and soil conditions involved — still matters for the wall’s long-term performance and safety.

Given how much variation exists in what “requires an engineer” actually means for your specific wall, getting a clear answer for your project from your contractor or council before proceeding avoids assuming the wrong threshold applies.

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