What the checker is reading
| State | Height trigger | How it is measured | Read from |
|---|---|---|---|
| NSW | 600 mm above or below ground level, and at least 2 m from any other retaining wall on the site | Above or below ground level | NSW Planning Portal |
| QLD | 1 m, and no surcharge behind it, and 1.5 m clear of a building or another wall — all three | Wall plus retained fill or cut, from finished ground level, footing excluded | Building Regulation 2021 Schedule 1 s 5 |
| VIC, WA, SA, TAS, ACT, NT | Not confirmed. Their legislation sites refused automated reads on the day this was written, so we publish no figure | ||
The load behind the wall matters more than the height
This is the single most useful thing on the page, and it is the thing the height-threshold articles bury.
Queensland writes it into the regulation as the first of three tests: the exemption applies only where “there is no surcharge loading over the zone of influence for the wall”. The regulation then defines both terms — a surcharge loading is a load applied to a soil stratum that has, or may have, the effect of consolidating it; the zone of influence is the volume of soil behind the wall that affects the wall’s structural integrity.
In plain terms: a driveway, a car, a shed, a pool or another wall sitting above your retaining wall changes the engineering completely. A 700 mm wall holding back a garden bed and a 700 mm wall holding back a driveway are not the same structure, and no height table can tell them apart. That is why this checker asks.
Terraced walls are not two small walls
Stepping a big wall into two little ones is the oldest way around a height threshold, and both states we could verify have closed it — differently.
- Queensland requires the wall to be “no closer than 1.5m to a building or another retaining wall”. Inside 1.5 m, the exemption is gone.
- New South Wales requires the wall to “be separated from any other retaining wall on the site horizontally by at least 2 metres”.
Two walls close together load each other. The upper wall is a surcharge on the lower one, which is the same problem as the driveway above.
Approval and engineering are two different questions
People ask “do I need council approval” and hear the answer to a different question. Not needing approval does not mean not needing an engineer, and it never means the wall is somebody else’s problem if it moves.
Queensland’s exemption is a statement about who checks the work, not a statement that the work is simple. If the wall retains a load, ask a structural or geotechnical engineer regardless of what the height table says. Our retaining wall calculator works out blocks, base and drainage for a wall you have already decided to build.
Why six states are blank, and why that is the honest answer
On 3 September 2026 the NSW, WA and SA legislation sites returned 403 Forbidden to an automated read, the Victorian regulator’s practice note did the same, and the Queensland regulation was only readable by pulling the PDF and extracting the text. We got Queensland from the instrument and New South Wales from the state planning portal. The rest we did not get, so the rest is blank.
For Victoria, Western Australia and South Australia the checker names the figure that circulates online and tells you to treat it as a question to ask rather than an answer to build to. That is a deliberate choice: a homeowner who knows what to ask their council is better off than one told nothing, and far better off than one given a number nobody checked.
The Western Australian case is the interesting one. A 500 mm threshold is quoted by council after council. We searched the Building Regulations 2012 consolidation and found no retaining-wall provision at all. That may mean our read was incomplete, or it may mean the 500 mm figure lives in local government practice rather than in the regulations. We do not know which, so we say so.
A word on “current as at”
The Queensland reprint behind this page is headed “Current as at 14 August 2026”. That is the date the text was last consolidated, not proof that nothing has commenced since. It is the trap that has already caught one page on this site: a regulation cited the day after its replacement commenced. Where a state authority also publishes a plain-English page, we read that too, and both links are in the answer above.
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General information for Australian homeowners and trades — not legal, planning, building or engineering advice, and not a substitute for your council, a building surveyor or a structural engineer. Building and planning rules change, and your council can be stricter than the state rule. Every figure on this page carries the source it was read from and the date it was read; check it against that source before you rely on it. No regulator has reviewed this page. Yamate does not issue, lodge or approve anything.