Technical article by WAHA CEO, Scott Barber.

When we talk about working safely on roofs in Australia, there’s one detail that often flies under the radar, but has big implications for safety planning; roof pitch.

When it comes to working safely on roofs, pitch angle is one of the most underestimated risk factors in Australian workplaces. While most safety professionals are familiar with the 26° pitch threshold, commonly cited in state-based regulations, few realise that Australia’s Model Code of Practice also flags 15° as a critical risk point. This difference matters, especially for those designing or approving fall protection systems in housing, maintenance, and construction. As a critical marker, this is one that significantly influences the type of height safety systems required and should be implemented as defined under Australian Codes of Practice.

Why Pitch Angle Matters

In height safety, slope affects everything; worker footing, equipment stability, anchor effectiveness, and the speed/severity of a fall. The steeper the pitch, the less margin for error. But there is currently no single Australian regulation that defines all roof pitch requirements.

According to the Safe Work Australia Model Code of Practice: Managing the Risk of Falls at Workplaces, once the roof pitch exceeds 15°, the risk of slipping and falling rises significantly. This shift in slope is enough to trigger recommendations for additional fall prevention measures, particularly passive systems. Subsequently, they recommend risk-based decision making as the process adopted:

“On sloping roofs, particularly where the pitch exceeds 15 degrees, the risk of slipping is higher and additional controls are usually needed.”
— Safe Work Australia, Model Code of Practice, s2.4.2

While this isn’t a strict cutoff like the 26° trigger, it reflects a shift in best-practice thinking: fall risks aren’t just about height, they’re about angle, surface, and control.

Passive vs Active Fall Protection: What the Regulations Say

The Model WHS Regulations and related Codes of Practice clearly outline a hierarchy of control for managing fall risks, prioritising:

1. Passive fall protection systems (collective controls):
   • Guardrails
   • Walkways
   • Edge protection
   • Work platforms
   • Safety mesh (for internal fall prevention)
2. Active fall protection systems (individual controls):
   • Fall restraint systems
   • Fall arrest harnesses and lanyards (PFAS)
   • Self-retracting lifelines (SRLs)

Regulation Reference

WHS Regulation Clause 36 – Safe Design of Plant: requires that hazards (including falls) are eliminated or minimised so far as is reasonably practicable using the hierarchy of control.

Model Code – Managing the Risk of Falls (Section 2.3):
“Passive fall prevention devices… provide the highest level of protection and should be used in preference to work positioning or fall arrest systems wherever practicable.”

In practice, this means that passive safety systems, like edge protection or temporary guardrails, should be used before relying on a harness-based solutions, especially where slope and surface increase fall potential.

State & Territory Summary: Roof Pitch and System Choice

Jurisdiction	Pitch Threshold	Key Requirements & Systems Referenced
National Model	> 15°	Use pitch in risk assessment and system selection (passive → active)
Victoria	> 15° / > 26°	“Roof work on a pitch greater than 15 degrees increases the risk of a fall and additional fall protection measures must be provided.”
Queensland	> 26°	Additional controls (e.g. scaffold, harness systems) for housing construction.
New South Wales (via Model)	Implicit	Adopt hierarchy: guardrails > restraint > arrest systems.
Western Australia	Requires Assessment	WA expects pitch to form part of your risk assessment and system selection but doesn’t quote an angle.
South Australia	> 26°	“Builders and subcontractors should determine the critical angle… below the angle at which roof workers may reasonably be able to work and walk across the roof”
Tasmania	Undefined	Replicates the National Model Code. The “critical angle” is defined as the maximum roof pitch at which a worker can reasonably stand and work without additional fall protection.
Northern Territory	> 15°	Aligns with National Model Code and applies the pitch angle in risk assessment and system selection (passive → active)
Australian Capital Territory	>10° and > 26°	Hierarchy based at > 26° and adjusts guardrail height for every 10° increase in angle

Passive vs Active Systems: Applying the Hierarchy of Controls

Under the Model WHS Regulations, Clause 36 (Safe Design of Plant) and related codes, employers and designers must:

• Eliminate the risk where possible.
• If not, minimise it using the hierarchy of controls.

That means:

1. Passive systems first – guardrails, edge protection
2. Then work positioning/restraint
3. Lastly, fall arrest as a last resort

“Passive fall prevention devices provide the highest level of protection and should be used in preference to work positioning or fall arrest systems wherever practicable.”
– Model Code of Practice: Managing the Risk of Falls, s2.3

Choosing the Right System for the Roof Pitch

Roof Pitch	Typical Control Strategy
0–15°	Edge protection, parapets, non-slip surfaces (passive)
15–26°	Roof ladders, mesh, edge protection, fall restraint (mixed)
>26°	Scaffolding, catch platforms, fall arrest (active+passive)

Practical Recommendations

If you’re supervising or designing work at heights:

• Don’t wait for 26° to trigger controls, use collective protection, anchor points, and effective restraint/arrest systems proactively.
• Consider pitch angle in your Safe Work Method Statements (SWMS) and initial design stage assessments.
• Treat >15° as a tipping point for increased vigilance and system design, not a grey area.

• Treat >15° as a trigger for formal fall prevention planning.
• Default to passive systems first, as per the WHS hierarchy.
• Use safety mesh and internal barriers during construction, not just external edge controls.
• Include pitch angle in your Safe Work Method Statements (SWMS) and design reviews.

Final Thoughts

Too often, the industry sees passive systems as optional or overkill. But the WHS Codes and Regulations make it clear; passive fall protection is not only best practice, it’s the legal priority where reasonably practicable.

Whether you’re building homes, constructing commercial buildings, servicing roofs, doing maintenance or installing solar systems, remember,15° is not a safe slope without controls. The smarter and safer move is to plan fall protection early and plan it right.