Ever wonder how windows get cleaned on tall buildings?

If you manage a high-rise building, a bosun chair is not just equipment. It is an access, safety, and planning decision.

If you manage a mid-rise, high-rise, condo tower, commercial building, or institutional property, window cleaning is not just a maintenance task.

It is an access decision.

The platform or access method affects worker safety, cleaning quality, job timing, tenant disruption, public-area control, and cost. Ontario’s 2025 Construction Death Review found that falls from heights accounted for 43% of all construction fatalities in the province over the past 15 years, based on 131 fall-from-height deaths from 2009 to 2024. That is why high-rise access decisions should be made before anyone compares price per pane.

Lets Compare high-rise window cleaning platforms, including bosun chairs, swing stages, rope access, lifts, davits, and BMUs.

What Are High-Rise Window Cleaning Platforms?

High-rise window cleaning platforms are access systems that help trained crews reach exterior glass, frames, ledges, and façade areas above ground level.

The main options include:

• Bosun’s chairs
• Suspended scaffolds or swing stages
• Rope access systems
• Scissor lifts and man lifts
• Telescopic boom lifts
• Davit and outrigger systems
• Building maintenance units, also called BMUs

There is no single best platform for every building. The right choice depends on the façade shape, roof access, anchor points, building height, glass layout, public space below, work frequency, and rescue planning.

Key Takeaways for Property Managers

• A platform should match the building, not the contractor’s habit.
• Bosun’s chairs work best for narrow or targeted drops.
• Swing stages work better for wider, repeated glass sections.
• Rope access works well for hard-to-reach areas and difficult façade geometry.
• Boom lifts and scissor lifts help when the work area is reachable from ground level.
• BMUs make sense for buildings designed for permanent exterior access.
• In Ontario, suspended scaffold and boatswain chair work requires planning, training, supervision, anchor information, and worker access to a work plan.
• A low quote is not useful if the access method is wrong for the site.

Why Platform Choice Matters

The access method changes the whole job.

It affects:

• How many workers are needed
• How long setup takes
• What roof access is required
• How much glass can be cleaned per drop
• Whether public areas need barriers
• Whether balconies, podiums, trees, or canopies block access
• How the crew handles wind, rain, heat, or ice
• Whether the building owner needs to provide anchor sketches or access records
• How quickly a worker can be helped in an emergency

Ontario Regulation 859 requires building owners to prepare sketches showing anchor points and related structures suitable for suspended scaffolds, boatswain’s chairs, similar single-point suspension equipment, and lifelines before that equipment is used for window cleaning.

For property managers, this means platform selection is not just a contractor preference. It is part of building safety planning.

Types of High-Rise Window Cleaning Platforms

Suspended Access Equipment:

Bosun’s Chair (single-point suspension)

A bosun’s chair, also called a boatswain’s chair, is a single-worker suspended seat used for exterior window cleaning and light façade access.

It is usually used where a full platform is too large or unnecessary.

Best for

• Narrow vertical drops
• Recessed windows
• Hard-to-reach glass
• Spot cleaning
• Smaller façade sections
• Buildings where a swing stage is not practical

Watchouts

• It supports one worker at a time
• It has limited tool and bucket space
• It requires strong anchor planning
• It depends on proper lifelines and fall protection
• It is not ideal for wide glass elevations
• It may not be allowed or suitable for certain descents

Ontario’s guidance states that a boatswain’s chair must not be used where the descent exceeds 90 metres.

Suspended Scaffolds (two-point suspension, swing stages)

A suspended scaffold, often called a swing stage, is a platform suspended from above. It usually gives workers more room than a bosun’s chair and allows crews to clean larger sections of glass.

Best for

• Large commercial façades
• Condo towers with repeatable glass sections
• Regular maintenance routes
• Wider window bands
• Jobs where two workers need platform space

Watchouts

• Requires proper roof support or anchorage
• Needs load control
• Needs platform inspection
• Can be affected by wind and sway
• Takes more setup time than smaller systems
• May be blocked by balconies, canopies, or setback design

IHSA’s suspended access training explains that workers need to understand roof plans, work plans, fall arrest systems, suspended platform systems, safe setup, safe operation, and daily inspection.

Rope Access Systems

Rope access uses trained technicians, ropes, harnesses, descent devices, backup systems, and rescue planning to reach exterior glass and façade areas.

It is not the same thing as a bosun’s chair.

Best for

• Difficult building shapes
• Setbacks and recessed areas
• Atriums and architectural glass
• High-rise façade detail work
• Areas where a swing stage cannot sit properly
• Buildings with limited ground access

Watchouts

• Requires specialized training
• Requires strong supervision and rescue planning
• Requires a clear roof and anchor strategy
• May not be best for broad, repetitive glass sections
• Can be affected by wind and rope path issues

Manager note

Rope access is often the right choice when the building shape creates access problems. It is a method for controlled movement, not a shortcut around planning.

Telescopic Boom Lifts

A telescopic boom lift reaches out and up from a ground base. It can help crews access glass behind landscaping, overhangs, lower roofs, or setback areas.

Best for

• Mid-rise exterior glass
• Setback façades
• Glass above entrances
• Atriums with reach issues
• Buildings where straight vertical lift access does not work
• Areas blocked by landscaping or site layout

Watchouts

• Requires stable ground
• Needs enough space for positioning
• Can be limited by reach and angle
• Must be kept clear of power lines and traffic
• May need permits or site control in dense urban areas

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)

A Building Maintenance Unit is a permanent or semi-permanent exterior access system, usually installed on the roof or integrated into the building design.

BMUs may include a cradle, track, boom, hoist system, or roof car.

Best for

• Large towers
• Repeat exterior maintenance
• Complex architectural façades
• Buildings designed with permanent access systems
• Sites with frequent window cleaning and façade inspection needs

Watchouts

• High installation and maintenance cost
• Requires inspection and service records
• Depends on the building’s original design
• May not reach every unusual façade section
• Requires trained operation and emergency planning

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:

• Telescopic jibs or articulated arms to reach varying façade geometries

• Cradles (gondolas) that lower window cleaners or façade technicians

• 360° boom rotation for full exterior coverage

• 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:

• Monorail tracks

• Parapet rail systems

• Trolley-mounted gondolas

The cradle or platform can be lowered vertically via wire ropes and controlled remotely. These systems provide:

• Full coverage of convex/concave facades

• Low visual impact for architectural integrity

• 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:

• EN 1808 (European BMU safety standard)

• CSA Z271 (Canada – suspended powered platforms)

• ANSI A120.1 (USA – powered platform design)

Essential safety features include:

• Emergency stop systems

• Load limiters

• Anti-collision bumpers

• Wind-speed detectors

 Key Benefits of BMUs

High-Rise Window Cleaning Platform Comparison Table