Building Maintenance Unit (BMU) Operations SWMS

Building Maintenance Unit (BMU) operations involve the use of permanently installed davit arms, monorails, and powered suspended cradles to access high-rise facades for window cleaning, sealant replacement, and external repairs. This work is captured under WHS Regulation 2025 section 291 as High Risk Construction Work because operators work at heights exceeding 2 metres on suspended platforms, with fall consequences that are almost universally fatal. A Safe Work Method Statement is mandatory before any BMU deployment commences and must be prepared in consultation with the workers performing the task, the building owner, and the BMU service contractor. The SWMS must address AS 1418.13 design and inspection requirements, AS 2550.13 in-service criteria, secondary fall arrest provisions, wind speed restrictions, rescue planning, and operator competency verification. Without a compliant SWMS reviewed at each shift, the PCBU breaches both s19 primary duty of care and section 291 documentation obligations under the WHS Regulation 2025.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.

1. 1Elimination — schedule facade inspections via drone photogrammetry or reach-and-wash pole systems from ground level where building height and access geometry permit complete coverage.
2. 2Elimination — relocate non-urgent maintenance tasks to internal building access via openable windows or maintenance hatches removing the need for external cradle deployment entirely.
3. 3Substitution — substitute traditional davit-and-cradle with permanently installed monorail BMU featuring redundant wire ropes and automatic overspeed governors compliant with AS 1418.13.
4. 4Engineering — verify BMU has dual independent wire ropes, secondary fall arrest static line, and certified overload limiter inspected within 12 months under AS 2550.13 logbook.
5. 5Engineering — install rooftop edge protection, davit base anchors load-tested to 15kN, and dedicated 240V isolated cradle power supply with RCD protection and emergency descent battery.
6. 6Administrative — implement daily pre-start inspection checklist covering wire rope condition, brake function, limit switches, harness inspection, anemometer reading, and competent operator licence verification.
7. 7Administrative — establish wind speed cease-work trigger at 36 km/h sustained measured by rooftop anemometer; cancel work and dock cradle if forecast exceeds threshold within shift window.
8. 8Administrative — enforce ground-level exclusion zone with spotters, signage, and physical barriers extending minimum 1/10th of working height from facade perimeter.
9. 9PPE — full body harness rated to AS/NZS 1891.1 with dual lanyards attached to independent cradle anchor and secondary building static line, inspected pre-use.
10. 10PPE — hard hat with chinstrap, cut-resistant gloves, safety glasses, hi-vis long sleeves, and trauma relief straps integrated into harness for suspension trauma mitigation.

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

At a 32-storey commercial tower undergoing quarterly facade cleaning, the supervisor convenes a rooftop pre-start brief at 6:45am with two IRATA-trained operators. The BMU SWMS is laid on the davit base, and the team works through it section by section. Rooftop anemometer reads 18 km/h sustained — below the 36 km/h trigger — but the BOM forecast shows a southerly change at 11am, so the supervisor sets a hard finish time of 10:30am and notes it on the SWMS daily record. Wire rope inspection identifies minor surface corrosion on the secondary rope; the SWMS hazard register flags this as monitor-only because the AS 2550.13 12-month inspection certificate is current and discard criteria not yet met. Both operators sign on, attach primary lanyards to cradle anchors and secondary lanyards to the independent rooftop static line, and confirm trauma relief straps are deployable. Mid-task at level 18, a delivery truck enters the ground-level exclusion zone. The spotter radios the cradle, operators secure tools into the tethered bucket, and descent is paused until the truck departs and barriers are reset — this dynamic control adjustment is logged on the back of the SWMS as a real-time amendment, initialled by both operators, demonstrating the document is a living field tool not a filing-cabinet artefact.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• Managing the Risk of Falls at Workplaces CoP

Frequently asked questions