Can a retaining wall be part of my pool barrier?

Can a retaining wall be part of my pool barrier?

Yes, on two conditions: the wall is high enough measured from the side a child would approach from, and its face does not give a child a foothold. Western Australia's Rules for Pools and Spas (December 2025 edition) states that retaining walls may form part of a safety barrier, including a boundary barrier, and that a wall which does not meet the requirements "cannot be used as part of the safety barrier and an alternative safety barrier must be provided".

The single most useful idea on this page is the which-side test: a retaining wall's height counts from the ground a child stands on, not from the side you look at it from. A 1.2m wall that drops away from the pool is 1.2m to a child below it. The same wall holding up a garden above the pool is a step down into the pool area for a child on top, so the number that matters is the drop on the pool side.

Most of the rules trace to AS 1926.1. This page reads two regulators' published guidance on it: Western Australia's and Victoria's. For how the zones work in general, see the non-climbable zone rules.

A retaining wall below the pool: 1.2m with a clear face, or 1.8m

This is the common case on a sloping block: the pool sits on the high ground and the wall drops away towards the lower garden or the neighbour. A child climbs up the face of the wall from below.

WA's guide accepts the wall as the barrier if it does not slope towards the pool by more than 15 degrees to the vertical and either has a minimum height of 1.2m on the non-poolside with no climbable surfaces within non-climbable zones 1, 2 and 3, or is at least 1.8m high on the non-poolside. Victoria's checklist for pools from 1 May 2010 says the same in its own words: at least 1800mm, or at least 1200mm with a surface resistant to climbing including a 900mm non-climbable zone.

In practice the face decides it. A sleeper wall has a horizontal joint every sleeper, block walls have capping, and stone walls have ledges. Under the non-climbable zone rules a horizontal surface deeper than 10mm is a foothold, so a 1.2m wall that would pass on height often fails on its face. At 1.8m the face no longer matters under the WA guide. If a wall is lower than 1.2m, it cannot be the barrier on its own; the retaining wall cost page shows the approval heights for the wall itself in each state.

A retaining wall above the pool: where WA and Victoria disagree

When the pool is cut into the slope and the wall holds up the ground behind it, a child arrives from the top. WA's guide says the wall can be used if it does not slope away from the pool by more than 15 degrees and "has a height of at least 1.8 m on the poolside", and that a wall under 1.8m "cannot be used".

Victoria's checklist for pools from 1 May 2010 is less strict for newer barriers: at least 1800mm, or, if the building permit was issued from 1 May 2013, at least 1200mm with a surface that is resistant to climbing. Both documents describe barriers built to AS 1926.1-2012, so for a wall above the pool between 1.2m and 1.8m the two regulators' published guidance does not agree. We have not read the standard itself, which is sold rather than published. Your building surveyor or certifier decides, and the WA figure is the safer one to design to.

Older Victorian pools were held to higher numbers. The checklists for pools installed before 1 May 2010 give an effective height of at least 2400mm for a wall on the high side, and 1200mm with limited footholds, or 2400mm, on the low side. Checklist 2 applies that step only to pools approved from 1 November 1994. If you are buying a house with an older pool, how to pass a barrier inspection first time covers what an inspector walks through.

Why a retaining wall near your pool fence changes its height

This is the rule people trip over. A fence is measured from the finished ground beside it, and a wall, step or level change right next to the fence becomes that ground. WA's guide puts it as a distance: objects, steps, retaining walls or ground level changes that reduce the minimum height of the barrier must not be within 500mm of it. Queensland's regulator gives the same advice in plain terms: reduce the height of surrounding ground levels and garden beds so the whole fence is at least 1200mm from the ground.

Worked example. The pool is on the low side. A 700mm retaining wall holds the garden up behind the pool, and the pool fence is a 1200mm fence standing at the foot of the wall. From the garden, the top of the wall is within 500mm of the fence, so the fence is measured from there: 1200 − 700 = 500mm. To keep 1200mm above the top of the wall, the fence would have to be 1200 + 700 = 1900mm from the pool-side paving. The other options are to set the fence on the high ground, at least 500mm back from the edge of the wall, or to move the fence line so the wall is no longer within 500mm.

The same arithmetic applies to raised garden beds and planter walls added years after the pool passed inspection. The 500mm setback around a pool fence covers the clear zone in full.

Where the pool fence meets the wall, and walls on the boundary

Where a fence on top of or beside a retaining wall runs into the wall, WA's guide requires the fence to either extend past the outer edge of the wall by 900mm, or extend to the edge and return 900mm along the wall in either direction, with the outside face of the fence flush against the face of the wall. The return stops a child stepping around the end of the fence along the top of the wall.

A retaining wall on the boundary is a boundary barrier, and the guide says it must meet one of the boundary options: at least 1.8m on the poolside with non-climbable zone 5 measured 900mm down from the top, or at least 1.2m on the neighbour's side with a 500mm clear area and zones 1 to 4. The guide suggests the second option suits cases where the pool is on the high side of a significant retaining wall, because the owner controls more of what sits against it. Using a boundary fence as the pool barrier covers the 1800mm rule.

A wall that has to double as the barrier is worth pricing as one item with the pool, not as landscaping afterwards. Building a pool on a sloping block covers the cut and fill; when the design is settled, compare pool quotes with the wall and the barrier priced as separate lines. Pool businesses are listed in Brisbane, Sydney, Melbourne and Perth.

Common questions

Sources

• WA Building and Energy: Rules for Pools and Spas, December 2025 edition, retaining walls, boundary barriers and the 500mm area
• WA Building and Energy: Swimming pool and spa safety barrier requirements
• VBA pool and spa safety barrier self-assessment checklist 3, pools from 1 May 2010 (Monash City Council copy, read via Internet Archive, 17 May 2025 capture)
• VBA pool and spa safety barrier self-assessment checklist 2, pools 8 April 1991 to 30 April 2010 (Monash City Council copy, read via Internet Archive, 16 May 2025 capture)
• VBA pool and spa safety barrier self-assessment checklist 1, pools before 8 April 1991 (Monash City Council copy, read via Internet Archive, 16 May 2025 capture)
• QBCC: Swimming pool safety laws, tips on ground levels and garden beds

General information only, current at 2026-10-14. Pool rules differ by state and by council, and penalty amounts are updated regularly. Confirm your own obligations with your council or a registered inspector before acting.