Quick answer: Pick a contractor who carries at least £5 million public liability insurance, provides a site-specific risk assessment and method statement before starting, uses water-fed poles instead of ladders wherever the height allows, and can demonstrate a recognised safety accreditation. Don’t choose a contractor based on price alone.
C-Thru external Cleaning Solutions has cleaned more than 2,000 properties a month across West Yorkshire since 2009. We carry £5 million public liability insurance, and our operatives are DBS-checked and uniformed. Here’s what to check before allowing a commercial window cleaning contractor onto your site.
Choosing a commercial window cleaning company is about more than finding someone who can make glass look clean. You also need to consider safety, insurance, access methods, water quality, reliability and the condition of your building.
The right contractor should be able to explain exactly how the work will be completed and what measures are in place to protect your property, employees, visitors and the cleaning team.
The 8-Point Commercial Window Cleaning Vetting Checklist
Before a contractor starts work, ask these eight questions.
| What to check | A safe contractor has | Red flag |
| Public liability insurance | £5 million minimum and certificate available on request | Can’t provide evidence of cover |
| Employers’ liability insurance | Appropriate cover for employees | Cannot provide a current certificate |
| Risk assessment | Site-specific assessment for your building | Generic document |
| Method statement | Written method covering your glazing and access | No clear method |
| Access method | Water-fed poles where appropriate | Ladders used unnecessarily at height |
| Water quality | Purified/deionised water | Ordinary tap water for reach-and-wash cleaning |
| Accreditation | Relevant industry or safety accreditation | No recognised credentials |
| Operatives | Trained, identifiable and professional staff | No identification or unclear staffing |
These checks can help facilities managers, landlords and business owners compare contractors on more than price.
Commercial Window Cleaning Insurance Requirements in the UK
Insurance is one of the first things you should check when choosing a commercial window cleaning company.
Public liability insurance of at least £5 million is commonly requested for commercial work by landlords and managing agents. Some public-sector sites, hospitals and schools may require £10 million of cover. Always check the actual requirements for your contract before work begins.
Employers’ liability insurance is different. The draft notes that businesses with employees must hold at least £5 million of employers’ liability cover under the Employers’ Liability (Compulsory Insurance) Act 1969. Ask to see a current certificate before allowing work to begin on your premises.
There is another important point to check: policy exclusions.
A contractor may have valid insurance but still have exclusions that affect the work being carried out. Height restrictions are one example. Ask whether the policy excludes work above a particular height and request confirmation in writing where necessary.
RAMS: The Risk Assessment and Method Statement Test
A proper RAMS (Risk Assessment and Method Statement) should be relevant to the building and the work being carried out.
The risk assessment identifies potential hazards and the controls required to manage them. The method statement explains how the cleaning work will be completed safely.
For commercial window cleaning, the assessment should take account of factors such as:
- Building height
- Glazing type
- Access requirements
- Public areas
- Employees and visitors
- Ground conditions
- Equipment
- Weather conditions
- Nearby hazards
A generic RAMS document may not properly reflect the risks of your particular site. Ask for the documentation before work starts, rather than waiting until the morning of the clean.
Water-Fed Pole vs Ladders: What Should Commercial Sites Use?
For many commercial buildings, water-fed pole systems can allow external windows to be cleaned from ground level.
The Work at Height Regulations 2005 set out a hierarchy that prioritises avoiding work at height where reasonably practicable. HSE guidance for window cleaning also discusses methods that can reduce the need to work at height.
A water-fed pole system, sometimes called reach and wash, allows an operative to clean windows from the ground using an extendable pole and purified water.
This can reduce the need for ladders and can also help minimise equipment placed around entrances, pavements and other busy areas.
Water-fed pole systems can reach significant heights, although the appropriate equipment and access method will depend on the individual building.
Ladders are not automatically banned. They can still be suitable for certain low-risk, short-duration tasks where appropriate. The correct access method should always be based on the building, task and risk assessment.
Three Commercial Window Cleaning Traps to Watch For
1. The Scratched Glass Problem
Glass can be damaged when inappropriate tools or techniques are used.
This is particularly important with specialist commercial glazing, including coated, tinted or architectural glass.
Before cleaning begins, ask the contractor about the cleaning methods and equipment they intend to use on your particular glazing.
Understanding the glass type and choosing an appropriate cleaning method can help reduce the risk of avoidable damage.
2. Insurance Height Exclusions
A contractor may have insurance but still have restrictions relating to the height or type of work covered.
Always check the policy rather than assuming that a certificate automatically covers every cleaning method and every part of your building.
Ask specifically whether there are any height exclusions that could affect your property.
3. Tap Water Instead of Purified Water
Water-fed pole systems generally use purified water to reduce mineral deposits and spotting when the glass dries.
The draft recommends checking the contractor’s water quality and asking about their PPM measurement. This is particularly relevant when cleaning large areas of commercial glazing where spotting can become noticeable.
What We See in the Field
I’m Philip Scott, and I founded C-Thru Cleaning in 2009.
Over the years, we’ve grown to clean more than 2,000 properties a month across Leeds, Bradford, Wakefield, Huddersfield and Halifax. We carry £5 million public liability insurance alongside £5 million employers’ liability insurance. Our operatives are DBS-checked and uniformed, and our commercial work uses reach-and-wash poles reaching up to 60 feet alongside traditional methods where appropriate.
Commercial customers often contact us after experiencing problems with previous contractors, such as inconsistent cleaning, communication issues or difficulty obtaining the necessary paperwork.
For us, reliability matters just as much as the appearance of the glass.
Commercial customers who use a regular cleaning service need consistency. The same cleaning standards should be maintained throughout the year, with a clear schedule and a contractor who can be contacted when something needs attention.
Frequently Asked Questions
How much insurance should a commercial window cleaner have?
The draft recommends checking for at least £5 million public liability insurance for most commercial sites, with some public-sector, hospital and school contracts requiring £10 million. Employers’ liability requirements should also be checked where the contractor employs staff. Always check the certificates and any policy exclusions.
What is a RAMS document?
RAMS stands for Risk Assessment and Method Statement.
The risk assessment identifies hazards associated with the work and the method statement explains how the work will be carried out safely. For commercial window cleaning, it should be relevant to the particular building and work involved.
Do I need a contractor with accreditation?
Accreditation is not necessarily a legal requirement, but recognised industry or safety schemes can provide additional information when assessing contractors.
The draft mentions FWC, SafeContractor, CHAS and IPAF, depending on the type of work and equipment being used. Some commercial tenders may also specify particular requirements.
How often should commercial windows be cleaned?
Many offices and shopfronts may be cleaned every 4 to 8 weeks, while high-traffic premises may require more frequent cleaning.
The right schedule depends on factors such as the building’s location, traffic levels, glazing and environmental conditions.
Is purified water better than traditional window cleaning?
For high external glazing, purified water can be useful because it reduces mineral residue as the water dries.
It also allows many windows to be cleaned from ground level using a water-fed pole, reducing the need for ladders where the building and access conditions allow it.
What happens if my cleaner damages the glass?
If damage occurs, the contractor’s insurance arrangements may determine how repairs or replacement are handled.
This is why it is important to check insurance before work begins and to confirm that the policy covers the type and height of work being undertaken.
The Short Version
Choosing a commercial window cleaning company involves more than comparing prices.
Check the contractor’s insurance, ask for a suitable RAMS, understand the proposed access method, and ask about water quality when water-fed pole cleaning is being used.
A professional contractor should be able to explain how they will clean your building safely and consistently.
If you manage a building in West Yorkshire and want a professional assessment, contact C-Thru Cleaning for a free site survey. The team can assess your building, discuss the appropriate access method and cleaning frequency, and provide the relevant documentation before work begins.
About the Author
Philip Scott founded C-Thru External Cleaning Solutions in 2009 and has more than 20 years of experience in exterior cleaning across West Yorkshire.