Principal Contractor WHS Duties and Management Plan Obligations

s.309 WHS Regulation 2025

Management Plan Section

$250,000

Value Threshold

Diona v SafeWork NSW (2024)

Key Case Law

1 July 2026

Section 26A Commencement

1 December 2026

WEL Transition Date

s.291 WHS Regulation 2025

HRCW Definition

Section 309 of the WHS Regulation 2025 requires the principal contractor to prepare a written WHS management plan before work commences on a construction project that exceeds the $250,000 value threshold. The plan must identify the names and positions of persons with specific WHS responsibilities, describe the arrangements for managing WHS incidents, outline the site-specific WHS rules and how they will be communicated, describe the arrangements for collecting and assessing SWMS from subcontractors, and set out the arrangements for managing the WHS risks associated with the storage and movement of plant and materials. The management plan is a living document that must be reviewed whenever the nature or scope of the construction work changes. The principal contractor must keep the management plan on site and make it available to any person who requests it. Regulators treat the absence of a management plan, or a plan that does not reflect current site conditions, as a serious breach that typically results in a prohibition notice stopping all work until the plan is rectified.

The principal contractor must collect safe work method statements from every subcontractor performing high-risk construction work before that work commences. Collection alone is insufficient. The principal contractor must review each SWMS to confirm it identifies the hazards specific to the work, prescribes controls that are appropriate to the site conditions, and has been signed by the workers who will perform the work. Where a SWMS is inadequate, the principal contractor must require the subcontractor to revise it before work can proceed. The WHS Regulation 2025 introduces enhanced requirements for SWMS that involve work near energised electrical installations, work in contaminated or flammable atmospheres, and work involving the disturbance of asbestos-containing materials. The principal contractor must maintain a register of all SWMS on site, track version control, and ensure that superseded SWMS are removed from circulation. Under Section 26A, taking effect 1 July 2026, the principal contractor must also verify that each SWMS aligns with the applicable binding codes of practice for the relevant work category.

The decision in Diona Pty Ltd v SafeWork NSW (2024) significantly clarified the scope of principal contractor liability. The court held that the principal contractor's duty extends to ensuring that subcontractors actually implement the controls described in their SWMS, not merely that adequate SWMS exist on paper. The case arose from a trench collapse that injured a subcontractor's worker. The principal contractor had collected and reviewed the SWMS, which described adequate shoring requirements. However, the subcontractor did not install shoring, and the principal contractor's site supervisor did not verify that the control was in place before excavation exceeded 1.5 metres. The court found the principal contractor had failed to discharge its duty under section 309 because the WHS management plan did not include effective arrangements for verifying subcontractor compliance. This decision means principal contractors must now implement active monitoring systems, including scheduled inspections, photographic evidence of control implementation, and documented hold points where work cannot proceed until controls are verified by the principal contractor's representative.

Regulators have identified consistent patterns of failure among principal contractors. The most common include accepting SWMS without reviewing their content, failing to update the WHS management plan when new trades commence work, not maintaining a site-specific emergency plan that reflects the actual number and location of workers, and permitting concurrent work activities that create uncontrolled interface risks such as excavation near overhead crane operations. Enforcement trends show increasing use of category 2 prosecutions against principal contractors, with penalties regularly exceeding $500,000 for corporate PCBUs. The WHS Regulation 2025 has increased maximum penalties for category 2 offences, reflecting the legislative intent to hold principal contractors to a higher standard. Principal contractors should implement digital SWMS management platforms that automate collection, version control, and compliance checking. They should also establish daily site walk protocols with documented verification of subcontractor controls, and maintain photographic evidence of compliance at key hold points throughout the construction program.