Working at height: the 3 m and 5 m thresholds

There is no 3 metre rule in New Zealand law. The belief that falls only need managing above three metres is the most persistent myth in the trade, and WorkSafe has spent years correcting it. The duty applies to any fall that could injure someone. The 5 metre figure is real, but it triggers something else entirely.

Where the 3 metre idea came from

The old Health and Safety in Employment Act framework included a particular duty around falls of three metres or more, and the number stuck. It was never a line below which falls did not matter, and the framework that contained it has been superseded by the Health and Safety at Work Act 2015 and the 2016 regulations.

Under the current law there is no height threshold in the fall duty at all. Regulation 5 requires hazards to be identified, and regulation 6 sets the order for minimising the risk. Neither mentions a height.

Most falls that seriously injure people in New Zealand construction are from below three metres. Ladders, roofs on single-storey houses and scaffolding platforms account for a large share. A rule that excluded them would exclude the common case.

What the duty actually asks

The question is not how high, but whether a fall could cause injury and what is reasonably practicable to do about it. Work through regulation 6 in order:

1. Eliminate. Can the work be done from the ground? Prefabricating at ground level, using an extendable tool, assembling before lifting. This is first for a reason and it is skipped more often than it is impossible.
2. Substitute, isolate or engineer. A scaffold with edge protection, a mobile elevating work platform, a guardrail, a covered penetration. These sit at the same level and are frequently combined.
3. Administrative controls. Exclusion zones, sequencing, a permit, a method everyone has been briefed on.
4. PPE. A harness and fall arrest system, last, and only where the levels above are not reasonably practicable.

A harness also brings a duty with it. If a worker can be left suspended, there has to be a rescue plan that reaches them in minutes, which is covered in emergency plans and fall rescue.

What the 5 metre figure triggers

Regulation 26 of the Health and Safety in Employment Regulations 1995, which is still in force, requires notice to WorkSafe at least 24 hours before certain particular hazardous work starts. One category is work where a person could fall five metres or more.

That is a notification duty, not a safety threshold. Falling four metres is no safer; it just does not require you to tell WorkSafe first. The exclusions matter too, and the full list is in notifiable work: the 10 categories.

The same regulation separately catches erecting or dismantling scaffolding where a person could fall five metres or more, and excavation work deeper than 1.5 metres and deeper than it is wide.

So what do you write down?

A task document for the work at height, whatever the height, if a fall could hurt someone. It should name the actual fall distance and surface, say what was considered at each level of the hierarchy and why the chosen control was the highest reasonably practicable one, and set out the rescue arrangement where a harness is involved.

"Working at height, wear harness" is the version that fails, because it skips the three levels above PPE without saying why.

Ladders

Ladders are not banned and are not automatically unacceptable, but they are access equipment rather than a work platform. WorkSafe's position is that a ladder is appropriate for short duration, low risk work where three points of contact can be kept and the task does not require force, reach or carrying. Where the work takes longer than a few minutes or needs both hands, the ladder is the wrong tool and the hierarchy points somewhere else.

Roof work on a single-storey house

This is the case people most want an exemption for, and the one with the worst record. The eave height on a typical single-storey house is around 2.4 metres, below both the old 3 metre figure and the 5 metre notification threshold, and well within the range that causes permanent injury. Edge protection, a scaffold or a platform is the normal answer, and the Task Analysis should say why if it is not.

Sources

• Health and Safety at Work Act 2015, s22 (reasonably practicable) and s36 (primary duty of care)
• Health and Safety at Work (General Risk and Workplace Management) Regulations 2016, regs 5 to 8, particularly reg 6 (hierarchy of control measures)
• Health and Safety in Employment Regulations 1995, reg 26 (particular hazardous work requiring notice)
• WorkSafe New Zealand, Working at height in New Zealand, good practice guidelines
• WorkSafe New Zealand, Safe use of ladders and stepladders

This guide is general information about New Zealand health and safety law as at the review date. It is not legal advice and it does not describe your site. Confirm what applies to you with WorkSafe New Zealand or your adviser.