The Non-Climbable Zone — usually shortened to NCZ — is the rule that catches more Greater Geelong pool owners than fence height, latch height, and gate self-close combined. It’s a non-climbable zone on the outside (non-pool) side of the barrier — the side a child would climb from — swept as an arc from the top of the fence, where nothing can be present that gives a child a foothold to climb over. For pools built from May 2010 it is a 900 mm zone; pools built 1994–2010 (assessed under AS 1926.1-1993) are held to a larger 1200 mm zone. And the list of “things that count as climbable” is longer than most homeowners realise.
This guide explains exactly what AS 1926.1-2012 requires, what counts as a NCZ breach, and where the most common failures hide on Geelong, Bellarine, Moorabool and Wyndham properties.
What AS 1926.1-2012 Actually Requires
Australian Standard AS 1926.1-2012 — referenced by the Building Regulations 2018 (Vic) as the operative pool safety standard — defines two NCZs:
The 900 mm horizontal NCZ
Measured on the outside (non-pool) side of the barrier and swept as an arc from the top of the fence. Within this zone the ground level and all fixtures must be clear of climbable objects. The size is 900 mm for pools built from May 2010 (AS 1926.1-2007 / -2012) and 1200 mm for pools built 1994–2010 (AS 1926.1-1993). The purpose is to prevent a young chchild from using objects on the outside of the barrier as footholds to climb over it into the pool zone.
The inside 300 mm zone
On the inside (pool side), climbable horizontal surfaces must not sit within 300 mm of the barrier (AS 1926.1-1993), and under AS 1926.1-2012 a 900 mm-high by 300 mm-deep zone applies on the inside of barriers with vertical gaps between 10 mm and 100 mm. This is a separate inside rule — not a clearance measured above the top of the fence. The purpose is to prevent a child from outside using an overhanging feature to vault the barrier.
What Counts as Climbable
This is where most homeowners trip up. The standard isn’t “anything taller than 600 mm” — it’s anything that could give a child a foothold or handhold. Specifically:
- Plants and shrubs — anything woody or stiff enough to bear weight. Soft annuals don’t count; established roses, hedges, palms, and tree trunks do.
- Pool pumps and filter equipment — even small pumps are typically 300–500 mm tall. Gate latch height is a separate checkpoint assessed alongside the NCZ.
- Storage crates, pool toy boxes, towel storage — anything stable enough to stand on.
- Built-in seating, planter walls, retaining walls — even decorative ones.
- Steps, decking transitions, raised garden beds — anything creating a higher surface within 900 mm of the barrier.
- Horizontal rails on the outside of the fence — climbable rails on the outside (the side a child climbs from) act like ladder rungs; the vertical rail spacing rule governs this alongside NCZ. What matters is that no climbable horizontal rail — on either face — sits within the barrier’s clear span / non-climbable zone (note that an inside rail can fall within the inside non-climbable zone of an AS 1926.1-2012 barrier and still be a problem). The exact requirements depend on the standard your pool was built to — if you’re unsure, contact us to arrange an inspection.
- Ladders, hose reels, BBQ trolleys — anything portable that could be moved into the NCZ. Inspectors flag these on the day.
- Pool covers and reels mounted near the barrier — the reel itself is climbable.
Where Geelong-Area Inspectors Find NCZ Failures Most Often
1. Established gardens against the fence (older inland Geelong)
Newtown, Highton, Belmont, Grovedale homes from the 1970s–1990s typically have mature plantings — camellias, photinia hedges, palms — placed close to the pool fence. When the pool was first certified, the plants were small. 30 years later, they’re climbable structures inside the NCZ. Remediation usually means removing or relocating the planting; trimming alone doesn’t help if the trunk and main branches sit within 900 mm.
2. Pool equipment kept inside the enclosure
Most homeowners keep the pump, filter, chlorinator, and pool storage inside the pool fence — out of sight from the street. If any of this equipment sits within 900 mm of the barrier, it’s a NCZ failure. Common fix: relocate the equipment to a far corner, or build a small fenced-off plant room outside the main barrier.
3. Retaining walls and garden borders (sloped sites)
On sloped Geelong properties, retaining walls inside the pool zone are common. A retaining wall, step or raised surface that lets a child get a foothold within the non-climbable zone is a fail — there is no fixed height cut-off; the test is whether it provides a climbable foothold. We see this regularly in Wandana Heights, Highton, and Newtown.
4. Decking transitions and raised seating
Modern pool renovations often include built-in seating along the fence line, or a raised deck section adjacent to the barrier. If the seat or deck top is within 900 mm of the fence and itself raised more than 100 mm above the surrounding ground, it’s a NCZ fail.
5. Horizontal rails on the pool side of older fencing
Older steel-tube fencing often has horizontal rails on the inside (pool side) of the panels. Under the AS 1926.1-2012 standard an inside rail can fall within the inside non-climbable zone and be a problem in its own right. Whether a particular fence complies depends on the standard the pool was built to — if you’re unsure, contact us to arrange an inspection.
The Inside 300 mm Zone — Often Overlooked
On the inside (pool side), climbable horizontal surfaces must be kept clear of the barrier (300 mm under AS 1926.1-1993; and a 900 mm-high by 300 mm-deep inside zone under AS 1926.1-2012). Watch for:
- Tree branches overhanging the top of the fence (these fall within the outside over-the-top non-climbable arc) — even if the trunk is well outside, low branches inside the 300 mm zone are climbable.
- Pergola or carport rafters that pass over the fence — the rafter end inside the 300 mm zone is a problem.
- Power lines, irrigation pipes, anything mounted near the top of the fence.
This zone is measured straight up from the top of the barrier. Trim back overhanging vegetation; relocate any fixed structure inside the zone.
How NCZ Failures Are Recorded
If your barrier fails NCZ at inspection, the Form 24 non-conformance report includes:
- A photograph of each NCZ breach
- The specific item flagged (e.g., “Camellia within 600 mm of east boundary fence — climbable foothold”)
- The recommended remediation (relocation distance or removal)
NCZ remediation is more variable in cost than other Form 23 fails. Removing or relocating mature plantings can range $200 (one shrub) to $2000+ (mature palms requiring arborist removal). Check the Form 24 specifics before quoting remediation work.
The Pre-Inspection NCZ Walkthrough
Walk the entire outside perimeter of your pool fence (the side a child would approach and climb from). At every panel, ask:
- Is there anything within an arm’s-length of the fence (≈ 900 mm) that I could stand on, climb on, or use as a foothold?
- Is there anything overhanging or projecting from the fence itself within 300 mm above the top?
- Are pool pumps, hoses, or pool storage hard against the fence?
If any answer is yes — fix before you book. NCZ breaches are usually faster and cheaper to fix than to fail-and-re-inspect.
Why NCZ Compliance Matters Beyond Form 23
The 900 mm NCZ rule has been in AS 1926 since the 1980s, and the data behind it is unambiguous: drowning fatalities of children under 5 in Australia frequently involve barriers where the NCZ was breached by climbable features. The rule isn’t a bureaucratic gotcha — it’s the difference between a barrier that works and one that fails its single most important job.
For the full pool barrier inspection process and what else gets checked, see our complete Form 23 checkpoint guide.
Pool safety services we provide
Common NCZ questions
Which side of the pool fence is the NCZ on?
The outside (non-pool) side — the side a child would climb from — measured as an arc swept from the top of the fence. Separate rules apply on the inside: climbable surfaces must keep clear of the barrier, including a 900 mm high by 300 mm deep zone under AS 1926.1-2012 where vertical gaps are between 10 mm and 100 mm.
Is my NCZ 900 mm or 1200 mm?
Pools built from May 2010 (AS 1926.1-2007 / -2012) have a 900 mm zone. Pools built 1994–2010, assessed under AS 1926.1-1993, are held to a larger 1200 mm zone.
What counts as climbable inside the NCZ?
Anything that gives a child a foothold: mature plants and hedges, pool pumps and filters, retaining walls, raised garden beds and similar fixtures. The list is longer than most homeowners expect.
Not sure how the non-climbable zone falls on your block? A compliance consultation plans it for your specific site.
NCZ check on your pool? Book Form 23 inspection — $250 all-inclusive
VBA-registered inspector across Greater Geelong, Bellarine, Moorabool and Wyndham. Same-day Form 23 where compliant, free re-inspection if remediation is needed.
Call 0402 860 499 or book online.