PERMITS, IN PLAIN WORDS

Do you need a building permit for a retaining wall in Victoria?

Almost every answer you'll find online says "over one metre needs a permit." That's close enough to be misleading. Here's the actual rule, and the two conditions that catch people out.

A building permit is not required for "any retaining wall less than 1 m in height that is not associated with other building work or with protection of adjoining property."

— BUILDING REGULATIONS 2018 (VIC), REG 23 AND SCHEDULE 3

"Less than 1 metre" means less than.

A wall of exactly 1.000m is not exempt. If you're designing to the exemption, design to 950mm and measure it, because the exemption is one of the few places in the Regulations where the wording is less than rather than not exceeding.

A wall under a metre still needs a permit if it's part of other building work.

This is the condition almost nobody mentions. A 900mm wall built as part of a deck, a driveway, a shed, a pool or an extension is not exempt — at any height. The exemption is for a standalone wall doing nothing but holding back soil.

And it needs a permit if it's there to protect the property next door.

If the wall's job is retaining your neighbour's soil, or stopping your excavation affecting their land, the exemption doesn't apply regardless of height. That's "protection of adjoining property", and it brings in a whole separate process under Part 7 of the Regulations.

The two claims we see most, corrected

"You need an engineer's design over a metre." Not exactly. No regulation says the word "engineer." What a permit application requires is documentation proving the wall complies structurally — which in practice means engineering, and typically costs $800–$1,500 and adds a few weeks. But it's a consequence of proving compliance, not a standalone legal requirement, and knowing the difference is useful when someone quotes you for it.

"Under a metre, you can do whatever you like." No. A permit exemption is not a compliance exemption. An exempt wall still has to comply with the Building Code of Australia, and the municipal building surveyor can still require retaining works where ground stability on your block or next door is affected.

[UNPUBLISHED — what about the fence on top? How fence-height thresholds are measured where the fence sits on a retaining wall is NOT yet verified. Get it in writing from the building surveyor at Greater Dandenong or Monash, then write this section. Do not publish until confirmed.]

WE DON'T BUILD RETAINING WALLS.

We build the fence that goes on top of one, and we work with people who build the wall. If you need both, tell us and we'll put you in front of someone who does the wall properly — we don't take a cut for it and we'll tell you if we think you don't need a wall at all.

Sourced from the Building Regulations 2018 (Vic), authorised version in force 1 July 2026 — reg 23 and Schedule 3 — and the Building and Plumbing Commission's Practice Note BP-01. Last checked 16 August 2026. This is general information, not legal advice, and your building surveyor's view of your specific wall is the one that counts.

Get the fence priced.

Wall or no wall, the fence on top is our job. Photos and a rough length, estimate back today.