This is a plain-English summary of the rules for a typical residential lot, not legal advice. Rules change, and your council's planning scheme, overlays, easements or a heritage listing can override the general limits. Before you dig, check with your council or a private certifier.
The limits at a glance
| Where | Without approval, up to | Key conditions | Instrument |
|---|---|---|---|
| NSW | 600 mm | ≥1 m from every lot boundary; ≥2 m from any other retaining wall; ≥1 m from easements and sewer or water mains; ≥40 m from a waterbody; drains to the existing stormwater system; not on a heritage item | State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, Part 2, Subdivision 15 |
| VIC | under 1 m | Not connected with other building work and not protecting adjoining land | Building Regulations 2018, Schedule 3 (VBA Practice Note 32) |
| QLD | 1 m | No surcharge over the wall's zone of influence; ≥1.5 m from a building or another retaining wall; not part of a pool fence | Building Regulation 2021, Schedule 1, section 3 |
| WA | 0.5 m retained | A permit is needed above 0.5 m where the wall is linked to other building work or protects adjoining land; some councils want an engineer at any height | Building Regulations 2012 (council summaries) |
| SA | 1 m | Measured as the total change in ground level, including tiered walls; wall plus fence ≤2.1 m from the low side | Planning, Development and Infrastructure Act 2016 and General Regulations 2017 |
| TAS | 0.5 m / 1.2 m | 0.5 m within 1.5 m of a boundary, road or right of way; 1.2 m elsewhere; not in an easement or landslide hazard area | Director's Determination – Categories of Building and Demolition Work |
| ACT | 1.2 m (building) | Development approval limits are lower: 0.4 m between the front boundary and the house, and within 1.5 m of side or rear boundaries | Building (General) Regulation 2008, Sch 1; Planning (Exempt Development) Regulation 2023, Sch 1 s 1.50 |
| New Zealand | 1.5 m | Retains no more than 1.5 m of ground and supports no surcharge (driveway, parking, building, sloping ground above) | Building Act 2004, Schedule 1 (exempt building work) |
How height is measured
"Height" does not mean the same thing everywhere, and the difference can decide whether you need approval.
- Queensland counts the wall plus the retained fill or cut, measured from the finished ground at the footing.
- South Australia uses the difference in ground level, and tiered walls count the total. Two 700 mm walls stepped up a slope retain 1.4 m.
- The ACT measures from the top of the wall to the lowest ground next to it.
- New Zealand counts the depth of ground retained.
The safe reading everywhere is the full difference between the lowest finished ground in front of the wall and the ground it holds up. A block wall is taller than that, because its first course is buried, but it is the retained height that the rules care about.
State by state
New South Wales: 600 mm, with distances
Retaining walls up to 600 mm are exempt development under the Codes SEPP, but only if every condition is met. The wall must be at least 1 m from any lot boundary and at least 2 m from any other retaining wall. It must be at least 1 m from registered easements and sewer or water mains, and at least 40 m from a natural waterbody. It must not redirect water onto a neighbour, and its drainage must connect to the existing stormwater system. Some websites quote 900 mm from the boundary. The NSW Planning Portal and council fact sheets say 1 m. Above 600 mm, or closer to a boundary, the wall can be complying development through a certifier, or needs a development application.
Victoria: under 1 m
A retaining wall under 1 m high needs no building permit, provided it is not associated with other building work and is not needed to protect adjoining land. The VBA's practice note adds that a wall on or near a boundary needs a permit where the neighbour's property could be damaged. Planning scheme overlays may also apply.
Queensland: 1 m, and 1.5 m from buildings
The Building Regulation 2021 treats a wall as accepted development when three tests are all met. There is no surcharge over the wall's zone of influence. The wall plus retained fill or cut is no more than 1 m high. And it is at least 1.5 m from a building or another retaining wall. It must not form part of a pool barrier. The 1.5 m distance rule is the one most often missed: a 900 mm wall hard against a shed or the house needs approval. Brisbane City Council also notes that flood, landslide and heritage overlays can trigger planning approval.
Western Australia: 0.5 m
Councils summarising the Building Regulations 2012 say a building permit is needed for a wall that retains more than 0.5 m where it is associated with other building work or protects adjoining land. Setbacks under the Residential Design Codes grow with the height of the wall. Some councils, including Fremantle, ask for an engineer's design at any height, so check locally.
South Australia: 1 m of level difference
A wall that retains a difference in ground level of 1 m or less generally needs no approval. Tiered walls count the combined height. If a fence sits on top, the wall and fence together must not exceed 2.1 m measured from the lower side. Some zones and councils require approval even below 1 m.
Tasmania: depends on the boundary
Under the Director's Determination on categories of building work, a retaining wall is low-risk work with no permit up to 0.5 m within 1.5 m of a boundary, road or right of way. Elsewhere on the lot the limit is 1.2 m. Low-risk status does not apply in an easement or a landslide hazard band, and a planning permit may still be needed. Walls up to 1.8 m fall into a higher category that needs a licensed builder and an engineer's design. These figures come from the 2017 version of the Determination as reproduced by councils. Confirm them against the current version.
ACT: two separate tests
The ACT has separate rules for building approval and development approval, and a wall must pass both. Building approval: walls up to 1.2 m are exempt, and up to 1.5 m if they meet the exempt building code. Development approval: walls may be no higher than 0.4 m between the front boundary and the building line, and within 1.5 m of a side or rear boundary. Elsewhere the limits are 1.2 m for cut, 1 m for fill and 1.2 m for a combination.
New Zealand
Schedule 1 of the Building Act 2004 exempts a retaining wall from building consent if it retains no more than 1.5 m depth of ground and does not support any surcharge or additional load. MBIE's guidance gives driveways, parking areas, buildings and sloping ground above the wall as examples of surcharge. In rural zones, walls up to 3 m can be exempt if a Chartered Professional Engineer designs or reviews them and the wall is at least its own height from any boundary or building. Separately, a drop of 1 m or more may need a safety barrier under Building Code clause F4. A district plan can still require resource consent.
Surcharge: the rule that catches driveways
A surcharge is any extra load on the ground behind the wall. Examples are a driveway, a parked car, a shed or house footing, a pool, a stockpile or a slope rising above the wall. Queensland and New Zealand make "no surcharge" a condition of the exemption, and every engineering guide treats it as a major cause of failure. Queensland's legal definition leaves out loads from people or vehicles simply moving over the soil. Brisbane City Council still lists driveways and pools as surcharge examples, so treat a driveway behind a wall as needing approval and an engineer. Adbri's design guide gives a rule of thumb: keep loads behind the wall outside a line drawn up and back from its base at 1 vertical to 1.5 horizontal, or 1 to 2 in poorer soil.
When to use an engineer anyway
Approval rules are about paperwork, not physics. The Australian Geomechanics Society's guide on retaining walls recommends that walls over about 900 mm be designed by a geotechnical or structural engineer. Its main causes of failure are water pressure behind the wall, loads on the high side, digging at the toe, rotting timber or rusting steel, and building without engineering input. Terraced walls need space between them: Austral asks for at least 1.5 times the lower wall's height, and Firth more than twice. The retaining wall calculator checks your height against the limit for your state or New Zealand and works out the drainage the wall needs.
Questions
How high can a retaining wall be without council approval in NSW?
600 mm, if it is at least 1 m from every boundary, 2 m from any other retaining wall and 1 m from easements and mains, and its drainage connects to the stormwater system. Otherwise it needs complying development approval or a development application.
Do I need approval for a 1 m retaining wall in Queensland?
Not if it retains no more than 1 m, carries no surcharge and is at least 1.5 m from any building or other retaining wall. Planning overlays such as flood or landslide can still require approval.
Do tiered retaining walls count separately?
Not in South Australia, where the total change in ground level counts. NSW requires 2 m between walls and Queensland 1.5 m for each to be exempt on its own. For stability, space terraces at least 1.5–2 times the lower wall's height apart.
How high can a retaining wall be without consent in New Zealand?
1.5 m of retained ground, as long as nothing extra loads it: no driveway, parking, building or rising slope above. A drop of 1 m or more may still need a safety barrier.
Sources
- NSW Planning Portal, Exempt development: earthworks, retaining walls and structural supports; Wollondilly Shire Council, Retaining walls fact sheet.
- Victorian Building Authority, Practice Note 32-2018, When is a building permit required?
- Queensland Legislation, Building Regulation 2021, Schedule 1; Brisbane City Council, Retaining walls.
- City of Fremantle, Fences and retaining walls; City of Joondalup, Retaining walls and site works.
- Legal Services Commission of SA, Retaining walls; Law Handbook.
- Tasmania, Director's Determination – Categories of Building and Demolition Work (v1.3, 2017, council copy); Meander Valley Council, Low-risk building work: retaining walls.
- ACT Legislation Register, Building (General) Regulation 2008 and Planning (Exempt Development) Regulation 2023.
- MBIE, Building work that does not require a building consent (3rd edition) – Building Act 2004, Schedule 1.
- Australian Geomechanics Society, GeoGuide LR6: Retaining walls; Adbri Masonry, Segmental retaining wall specification; Austral Masonry, Technical design guide.
Last reviewed 23 September 2026 · Report an error