Falls are the biggest killer in construction, so the law is strict and the order of controls matters: eliminate first, guardrails and scaffold next, harness only as a last resort. Here is the hierarchy, the 2-metre trigger, the training, and the scaffold rules.
The fall-protection hierarchy — and when a harness is not enough
The order is fixed:
- Eliminate — work from the ground or solid construction where you can (prefabricate on the ground, use extendable tools).
- Passive / engineering — edge protection (guardrails), scaffolds, platforms, guarded EWPs, covers over penetrations.
- Administrative — exclusion zones, sequencing, permits, supervision.
- PPE — fall-arrest (harness, lanyard, anchor) as the last line.
A harness alone is not enough when a guarded edge or scaffold is reasonably practicable, when there is no compliant anchor, clearance or rescue plan, or when the work is regular and prolonged — an ongoing roof needs scaffold or edge protection, not just a harness. Regulators expect guardrails and scaffolds as the primary control; the harness is for short, residual tasks.
The 2-metre trigger
Under the model WHS Regulations, any risk of a fall of more than 2 metres must be formally managed through the hierarchy. Under 2m you still manage the risk, but the specific over-2m provisions do not apply. (Victoria's OHS and WA's WHS use the same practical 2m reference.)
Training
There is no single law naming a ticket, but the accepted benchmark is the nationally recognised "Work Safely at Heights" (RIIWHS204E) course — most principal contractors treat the Statement of Attainment as mandatory for anyone using fall-arrest, EWPs or doing roof work. Supervisors also need to handle the risk assessment, rescue planning and equipment inspection.
Scaffold — licensing and inspection
- A High Risk Work scaffolding licence is required where the scaffold can support a person AND something could fall more than 4 metres. The classes build up: Basic (SB) → Intermediate (SI) → Advanced (SA). Any scaffold over 4m must be erected, altered or dismantled by (or under the direct supervision of) the right licence class.
- Inspections: by a competent person before first use, then at least every 30 days, and again after any event affecting integrity (alteration, severe weather, impact). Use the green/amber/red tag system at the access points.
(More on licences in Scaffold Licences, BYDA & Plant Registration.)
The standards
- AS/NZS 1891 covers industrial fall-arrest systems — including part 1891.4 (selection, use and maintenance): a pre-use inspection every time, a detailed inspection by a competent person (commonly 6-monthly for construction harnesses, or per the manufacturer), only certified gear, rated anchors, and a planned rescue rather than an improvised one.
- AS/NZS 4576 (scaffolding guidelines) and AS/NZS 1576 (scaffold design) cover compatible components, fully decked and guardrailed platforms, and safe access.
The throughline: harnesses are the last line of defence; scaffold and edge protection are the standard for working at height.
Common mistakes
- Reaching for the harness first instead of edge protection or scaffold.
- No rescue plan for a fall-arrest setup.
- An out-of-licence person altering scaffold, or missing the 30-day inspection.
Know someone who needs this?
Keep reading
Was this guide useful?
Didn't find what you were looking for?
Spotted something wrong or out of date? Email us at hello@kilnguides.co.uk.
In crisis? Lifeline 13 11 14 ·