Working at heights

Working at heights is not defined by a single number. The model WHS Regulations deal with any situation where a person could fall from one level to another and be injured. That includes work on roofs, scaffolds, mobile scaffolds, elevated work platforms (EWPs), ladders and formwork decks, and work near open edges, stair voids, lift shafts, holes and penetrations.

Falling into an excavation or trench is also a fall risk. So is work on brittle or fragile surfaces such as old fibre cement roofing or skylights.

The fall risk must be managed at any height. The 2 metre figure matters because, under the model WHS Regulations, construction work that involves a risk of a person falling more than 2 metres is high risk construction work, and a SWMS must be prepared before it starts.

States differ. The Northern Territory has used a 3 metre trigger for some housing construction work. South Australia has also used a 3 metre trigger for some work and has amended its regulations to align with 2 metres. Victoria has its own Occupational Health and Safety Regulations 2017, which set specific duties for fall hazards above 2 metres. Always check the regulator guidance for the state where the work is done.

The model WHS Regulations set a specific order for falls, which follows the hierarchy of controls.

• Work on the ground. Do the work at ground level or on a solid construction where possible, such as prefabricating roof trusses or using extendable tools.

• Fall prevention devices. Use guardrails, edge protection, scaffolds, covers over penetrations and EWPs to stop a fall happening.

• Work positioning systems. Use systems such as travel restraint that stop a worker reaching an edge.

• Fall arrest systems. Use harnesses with anchors, static lines or catch nets to limit injury if a fall happens.

• Administrative controls. Ladders and procedures are the last resort, and only where higher controls are not reasonably practicable.

If a fall arrest system is used, the PCBU must have emergency and rescue procedures ready and tested, because a worker suspended in a harness needs to be rescued quickly.

• Treating low heights as safe. Many serious fall injuries happen from ladders and heights under 2 metres.

• Relying on harnesses first. Fall arrest is lower on the hierarchy than edge protection and should not be the default.

• No rescue plan. A harness without a tested rescue procedure leaves the worker at risk of suspension trauma.

• Uncovered or unmarked penetrations. Covers must be secured, strong enough and clearly marked.

• Scaffold altered without a handover. Scaffolds must only be altered by competent people and re-inspected afterwards.