Working hours become a WHS issue when rosters, overtime, night work, travel or inadequate recovery increase fatigue or extend exposure to hazards. Builders and subcontractors should assess the actual work pattern, not just the scheduled finish time, and adjust the work when people may no longer be fit to perform it safely.
Information current: 14 August 2026.
Why working hours matter on construction sites
Working hours include both how long a person works and when those hours are worked. Risk can increase through fatigue, reduced recovery time and longer exposure to noise, heat, vibration, hazardous substances and physically demanding work.
Fatigue can affect concentration, judgement, communication, hand-eye coordination, vigilance and reaction time. These effects are particularly serious when someone is:
- driving or operating mobile plant;
- working at heights or near live services;
- using powered tools or machinery;
- lifting, carrying or repeating demanding tasks;
- directing traffic or coordinating lifts; or
- making decisions where an error could seriously injure someone.
The total work pattern matters. Early starts, night work, extended overtime, call-backs, irregular rosters, long travel and another job can combine with workload and site conditions. A roster that appears manageable on paper may become unsafe after delays, rework, an emergency or a long trip home.
What should be sorted before work starts
Plan working hours alongside the construction program and site risk assessment. Before allocating the work, supervisors should understand:
- planned start and finish times, breaks and likely overtime;
- travel, mobilisation and call-back requirements;
- whether fatigue-critical work is scheduled at a low-alertness time;
- physical and mental task demands;
- environmental exposures that increase over a longer shift;
- available relief workers and competent supervision; and
- how workers will report fatigue or fitness-for-work concerns.
Consult workers and any health and safety representatives about the proposed roster and real site conditions. Review previous time records, incidents, near misses, delays and patterns of unplanned overtime. Include subcontractors whose hours on other sites or travel arrangements may affect the work being coordinated.
Practical controls and documents
Good controls address the causes of fatigue and exposure. Depending on the work, they may include redesigning the roster, moving critical tasks, limiting unplanned overtime, providing relief, rotating demanding work, scheduling regular breaks and allowing enough recovery between work periods.
Supervisors also need authority to pause or reallocate work when conditions change. Water, shade, lighting, amenities and suitable transport arrangements may support the system, but they do not replace sensible hours and recovery planning.
Useful documents and records commonly include:
- a working hours or fatigue management policy;
- rosters, timesheets and sign-on records showing actual hours;
- a site-specific fatigue or fitness-for-work assessment;
- pre-start, toolbox and consultation records;
- task risk assessments, permits and supervision arrangements;
- training and competency records; and
- incident, near-miss and corrective-action records.
These documents should agree with what is happening on site. Review the controls when the roster, task, crew, equipment, environment or program changes.
When a SWMS or another site document applies
Working extended hours does not by itself determine whether a safe work method statement is required. A SWMS commonly applies when the planned activity is high risk construction work under the requirements applying in the relevant jurisdiction.
Where fatigue or working hours can change the risk, the SWMS should address that interaction in practical terms. For example, it may identify when critical work will occur, required breaks, supervision, stop-work triggers, relief arrangements or a restriction on continuing after unplanned overtime.
Other work may be better supported by a site-specific fatigue assessment, roster plan, fitness-for-work procedure, job safety analysis, permit or emergency call-back arrangement. The document should match the activity and be communicated to the people doing and supervising the work.
Warning signs requiring action
Act when workers show repeated yawning, slowed reactions, poor communication, irritability, loss of concentration, unusual errors or difficulty following familiar steps. Other warnings include skipped breaks, frequent overtime, last-minute roster changes, near misses late in a shift, workers sleeping in vehicles, long drives after work or a culture of continuing until the job is finished.
A worker reporting fatigue is useful safety information. Reassess the task and arrange a safe response, such as rest, relief, rescheduling or alternative transport.
How Blue Safe can help
Blue Safe provides compliant WHS documents tailored to the client's activities, applicable Australian WHS/OHS requirements, jurisdiction and industry. This can include fatigue management policies, working hours procedures, site risk documents, SWMS and supporting consultation, training and record templates.
Blue Safe guarantees the document compliance of the WHS documents it provides, including eligible customer documents after Blue Safe has reviewed and upgraded them. Customers actively put the compliant documents into practice through controls, consultation, training, actions, records and evidence.
Official sources
- SafeWork SA - Codes of Practice
- SafeWork SA - Approved Code of Practice: Working Hours
- WorkSafe WA - Working Hours: Code of Practice
Local requirements vary, so check current regulator material for the jurisdiction and industry involved. Where a national Model Code is used for related risks, treat it as general orientation and confirm whether and how it applies locally.