Last Updated on December 18, 2025
Ever wonder how windows get cleaned on tall buildings?
It’s not magic—it’s smart equipment and skilled workers! From simple seats like Bosun’s Chairs to full suspended platforms, there’s a whole world of tools designed to make high-rise window cleaning safe and efficient.
Want to know the different types?
You’re in the right place.
This guide breaks down the key platforms used by pros, so you’ll quickly get the hang of how it all works.
Let’s take a closer look—no hard hats needed!
High Rise Window Cleaning Platforms
Cleaning windows on towering structures is a cinch when you’ve got a high-rise platform to rely on. Economical and mighty efficient, this method of washing windows has won the hearts of many. Yet, tread with caution when employing such a contraption, and keep these vital pointers in mind.
Also Read – How to Clean the Outsides of Your 3rd Floor Windows? [Guide]
Suspended Access Equipment:
Bosun’s Chair (single-point suspension)
Ah, the Bosun’s Chair – a mechanical marvel granting access to those pesky, hard-to-reach corners of buildings. Hang buckets from the chair’s base to tote your cleaning supplies. But beware, working at such dizzying heights can lead to back strain or even electrocution. Yikes!
Training and equipment are key when utilizing a Bosun’s Chair. Inspect every part diligently, and remember that safety has improved over time. For extra security, rope and pulley checks, a spotter, and grippy gloves are essential.
Suspended Scaffolds (two-point suspension, swing stages)
Suspended scaffolding provides a safe and sturdy workspace for cleaning windows on lofty buildings. To avoid hazards, design your platform with load and safety requirements in mind, especially if power lines are nearby. Guardrails in the right spots are a must.
Equip your suspended scaffold with a safety mechanism that boasts at least a fourfold safety factor when untethered. Choose between catenary scaffolds, supported by two parallel ropes, or adjustable scaffolds, hung by ropes or cables.
Also Read – High-rise Building Window Cleaning: Challenges and Solutions
Elevating Work Platforms (EWPs)
Man Lifts
Ladders are old news when you’ve got a high-rise platform to get the job done. These window-washing wonders are eco-friendly and come in various models, like man lifts and telescopic boom lifts. The latter can reach up to eight floors, making it a versatile tool for tasks beyond window cleaning, such as roof or siding installation.
Davits
For a secure, facade-accessing solution, davit high-rise platforms are the bee’s knees. Designed specifically for commercial window cleaning, these platforms are set up on rooftops or suspended from the ground using water-fed poles.
You’ve got options when creating your high-rise platform. Telescopic poles, outrigger systems, and boom lifts all come to mind. But safety comes first! Be well-versed in equipment usage and invest in top-notch, secure gear. Don’t hesitate to consult manufacturers for design assistance, either.
In ontario, proper training is required for operating EWPs, here you can get more info about EWP trainings in ontario.
Building Maintenance Units (BMUs)
Building Maintenance Units (BMUs) are the most advanced and permanent access systems used for exterior building maintenance—especially on high-rise and supertall structures. These engineered platforms are typically rooftop-mounted and either fixed in place or track-guided along the building’s parapet or structural rails.
Fixed & Rooftop-Mounted BMUs
These BMUs are permanently installed on the roof of a building and are custom-designed during the architectural or retrofit phase. They feature:
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Telescopic jibs or articulated arms to reach varying façade geometries
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Cradles (gondolas) that lower window cleaners or façade technicians
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360° boom rotation for full exterior coverage
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Weather-resistant enclosures to protect motors and control units
📌 Typical Use Cases: Skyscrapers, stadiums, curved glass buildings, architectural façades
Track-Based Gondola Systems
These units travel horizontally along the building perimeter using:
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Monorail tracks
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Parapet rail systems
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Trolley-mounted gondolas
The cradle or platform can be lowered vertically via wire ropes and controlled remotely. These systems provide:
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Full coverage of convex/concave facades
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Low visual impact for architectural integrity
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Automated movement with programmable controls
📌 Best For: Long-span towers, wave-shaped facades, towers with minimal roof access
Compliance & Safety Standards
BMUs are regulated under:
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EN 1808 (European BMU safety standard)
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CSA Z271 (Canada – suspended powered platforms)
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ANSI A120.1 (USA – powered platform design)
Essential safety features include:
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Emergency stop systems
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Load limiters
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Anti-collision bumpers
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Wind-speed detectors
Key Benefits of BMUs
| Benefit | Impact |
|---|---|
| Permanent integration | No setup/removal downtime |
| Architectural adaptability | Custom designs for complex facades |
| Operational efficiency | Faster deployment, reduced labor fatigue |
| Maximum safety compliance | Enforced by permanent fixtures and monitoring tech |
High-Rise Window Cleaning Platform Comparison Table
| Platform Type | Best Use Case | Typical Height Range | Anchor Requirement | Mobility | Training Required | Cost Efficiency | Regulatory Compliance |
|---|---|---|---|---|---|---|---|
| Bosun’s Chair | Narrow or irregular facades, retrofit jobs | Up to 300m+ | Yes (rooftop tie-backs) | High (manual reposition) | High (SPRAT/IRATA recommended) | ⭐⭐⭐⭐ | ANSI Z359, CSA Z91, OSHA 1910.27 |
| Suspended Scaffold (Swing Stage) | Standard commercial windows | Up to 500m | Yes (roof anchors/weights) | Medium (manual or motorized) | Yes (operator certification) | ⭐⭐⭐ | CSA Z271, ANSI A10.8, EN 1808 |
| Telescopic Boom Lift | Mid-rise buildings, glass atriums | Up to 24m (8 floors) | No (ground-based) | Medium to high | Yes (lift operation certification) | ⭐⭐⭐⭐ | ANSI A92.5, CSA B354 |
| Building Maintenance Unit (BMU) | Super-tall buildings, custom facades | Unlimited (customized) | Yes (permanent rooftop) | Low (fixed rails or jibs) | Yes (factory or OEM training) | ⭐⭐ | CSA Z271, ANSI A120.1, EN 1808 |
| Man Lift / Scissor Lift | Storefronts, stadiums, low-rise glass walls | Up to 15m | No | High (mobile base) | Yes (basic platform training) | ⭐⭐⭐⭐ | ANSI A92.6, CSA B354.2 |
| Davits + Outrigger Arms | Retrofit commercial buildings | Up to 150m+ | Yes (roof brackets) | Medium (modular setup) | Yes (fall protection + access) | ⭐⭐⭐ | OSHA 1926.451, CSA Z91 |
Platform-Specific Risks and Safety Measures
Every high-rise window cleaning platform comes with unique operational hazards. Understanding the risks tied to each system and implementing tailored safety protocols is vital for regulatory compliance and worker protection.
Bosun’s Chair
Common Hazards:
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Rope Abrasion: Friction wear on suspension lines due to edge contact or prolonged use
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Wind Sway: Lightweight setup is highly vulnerable to gust-induced pendulum effects
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Ergonomic Strain: Prolonged use can cause shoulder fatigue, lower back pain, and repetitive strain injuries
Safety Measures:
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Dual-rope system with fall arrest backup (CSA Z91)
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Use of edge rollers and rope protectors
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Daily rope integrity checks and anchor inspection
📌 Case Insight: A 2022 Toronto incident involved a worker falling 15 floors due to undetected rope fray near a parapet edge. CSA Z91 revisions now emphasize secondary anchoring.
Suspended Scaffold (Swing Stage)
Common Hazards:
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Cable Snap: Wear or corrosion can lead to uncontrolled descent
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Platform Overloading: Exceeding design weight limits (people + tools)
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Sway & Oscillation: Uneven loads and high winds cause lateral instability
Safety Measures:
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Load testing and labeling in line with ANSI A10.8
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Use of counterweights, tiebacks, and limit switches
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Wind-speed sensors and platform-leveling systems
📌 Compliance Failure: NYC DOB cited multiple contractors in 2023 for skipping daily load testing logs, contributing to 3 platform collapses within 12 months.
Telescopic Boom Lifts
Common Hazards:
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Tip-Over: Occurs from uneven terrain or improper outrigger deployment
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Collision: Contact with structures, people, or power lines
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Fall from Height: Due to platform gate failure or lack of harness use
Safety Measures:
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Full inspection of outrigger stability before elevation
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Operator certification (ANSI A92.5 / CSA B354)
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Tethered use of full-body harnesses with SRLs
📌 Incident Reference: OSHA records show a 2021 accident where an improperly stabilized boom lift in Chicago tipped over during window cleaning, causing fatal injury. Outriggers were not deployed on sloped concrete.
Building Maintenance Units (BMUs)
Common Hazards:
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Motor Malfunction: Sudden stoppage or failure of hoisting system
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Track Misalignment: Can derail the cradle from its rooftop path
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Weather Exposure: Water ingress can damage electrical systems over time
Safety Measures:
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Periodic load simulation tests per EN 1808 / CSA Z271
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Emergency descent devices + dual-motor redundancy
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Maintenance logs and predictive diagnostics
📌 Case Study: A 2020 case in Dubai involved a BMU cradle stuck for 4 hours due to electric motor failure. Lack of remote override delayed rescue and exposed workers to 45°C heat.
Let us do the high rise work for you?
What is the safest high-rise window cleaning platform?
BMUs and swing stages, when installed and operated per CSA Z271 / EN 1808, offer the highest safety due to redundancy systems, engineered tracks, and load stabilization features. However, Bosun’s chairs, despite their risk, are safe when used by SPRAT-certified technicians under strict procedural compliance.
How does a Bosun’s Chair differ from a swing stage?
A Bosun’s Chair is a single-user seat suspended by rope, ideal for narrow or hard-to-reach areas. A swing stage is a multi-person platform, supported by two ropes and motors, offering a larger work area and better stability for multi-story access.
Are building maintenance units permanent?
Yes. BMUs are permanently installed rooftop systems that provide long-term vertical access to building exteriors. They’re engineered to match specific architectural designs and are often included in the building’s original blueprints.
What training is required for rope access window cleaning?
Workers must hold certifications from SPRAT (Society of Professional Rope Access Technicians) or IRATA (Industrial Rope Access Trade Association). Training includes fall arrest procedures, anchor system knowledge, and rescue techniques.
