The Hierarchy of Fall Protection Controls Explained

What the hierarchy is and where it comes from

The hierarchy of fall protection controls is set out in the model WHS Regulations and adopted in every Australian state and territory (with Victoria operating under its own OHS Act but applying the same principles). It establishes the order in which a Person Conducting a Business or Undertaking (PCBU) must consider fall protection measures.

The hierarchy is not a menu. You cannot pick the option that is cheapest or most convenient. You must start at the top and only move to a lower-order control when you can demonstrate that the higher-order control is not reasonably practicable.

Level 1: Eliminate the risk

The first obligation is to eliminate the need to work at height altogether. This means designing maintenance tasks so they can be done from ground level, or designing the building so that equipment can be accessed without going on the roof.

Examples include ground-level HVAC controls, extendable gutter cleaning systems, and roof-mounted equipment with ground-accessible service panels. In practice, elimination is rarely achievable for all maintenance tasks, but it should always be the first question asked during building design.

Level 2: Passive fall prevention

If elimination is not reasonably practicable, the next control is passive fall prevention. These are physical barriers that prevent a person from falling, without requiring the person to do anything. The system works whether the person is trained or not.

Guardrails are the primary passive control. Installed along roof edges, around skylights, and at level changes, guardrails stop a fall from occurring. They do not require harnesses, anchor points, or any action from the worker. This is why guardrails sit above harness-based systems in the hierarchy.

AS 1657 sets the design and construction requirements for guardrails, including minimum height (900mm for industrial applications), infill requirements, and load ratings.

Level 3: Work positioning systems

Work positioning systems prevent a worker from reaching a fall edge. The worker is physically restrained from entering a fall zone. This includes travel restraint systems where a lanyard is short enough that the worker cannot reach the edge.

The distinction between restraint and arrest is important. A restraint system prevents the fall from occurring. A fall arrest system stops the fall after it has started. Restraint is the higher-order control.

Level 4: Fall arrest systems

Fall arrest systems stop a fall after it has begun. Anchor points, static lines, harnesses, and lanyards with energy absorbers are all fall arrest components. These systems are the most common height safety installations in Australian buildings because they are practical for a wide range of roof configurations.

However, because they allow the fall to begin before arresting it, they sit below passive controls and restraint systems in the hierarchy. They also require worker training, correct equipment selection, regular inspection, and rescue planning.

AS/NZS 1891.4 covers the selection, use and maintenance of personal fall protection equipment. AS 5532 covers the manufacturing requirements for anchor devices.

Level 5: Administrative controls

Administrative controls are the lowest level of the hierarchy. These include permit-to-work systems, safety signage, exclusion zones, and safe work method statements (SWMS). On their own, administrative controls do not prevent falls. They manage the risk through procedures and documentation.

A SWMS is mandatory for any high-risk construction work where there is a risk of falling more than 2 metres, but the SWMS itself does not replace physical fall protection.

What this means for building owners

Building owners and facility managers are PCBUs under the WHS Act. If a contractor falls from your roof while performing maintenance, the regulator will assess whether you provided adequate fall protection in line with the hierarchy.

Having anchor points installed is not sufficient if guardrails were reasonably practicable. Having a SWMS is not sufficient if physical controls were reasonably practicable. The hierarchy applies to the building, not just the work being done.

References

• Model WHS Regulations, Part 4.4: Falls
• Safe Work Australia Code of Practice: Managing the Risk of Falls at Workplaces
• AS 1657:2018: Fixed platforms, walkways, stairways and ladders
• AS/NZS 1891.4:2025: Selection, use and maintenance of fall protection equipment
• AS 5532:2025: Manufacturing requirements for anchor devices