7 Questions to Ask Before Hiring a Commercial Window Cleaner

Updated Jul 2026 · 3 min read

Before you sign a commercial window washing contract, a short list of pointed questions can save you from headaches later. The answers reveal whether a provider is properly prepared, fairly priced, and a good fit for your building. Here are seven to ask every candidate.

1. Are you insured, and can I see proof?

This is the non-negotiable first question. Ask specifically about liability insurance and workers' compensation, and request current certificates. A legitimate provider will supply them without hesitation. If a company is vague or reluctant, treat it as a serious warning sign and move on. Insurance protects your business if a worker is injured on-site or something is damaged during the job.

2. What equipment will you use on my building?

The right method depends on your building's height and access. Ask how they'll reach your glass — water-fed poles, ladders, lifts, or rope access — and confirm the crew is trained on that equipment. This question quickly reveals whether a provider is genuinely equipped for your property or stretching beyond their capability.

3. Exactly what does the service include?

Get the scope in writing. Does the visit cover exterior glass, interior glass, or both? Are frames, sills, tracks, and screens included? What about skylights or glass doors? Clarifying this upfront prevents the common dispute where a manager expects more than the crew was contracted to deliver.

4. Can you provide references from similar properties?

A provider experienced with buildings like yours is a safer bet. Ask for references from comparable commercial properties — similar height, similar use — and follow up with a call or two. Combine this with a look at their public reviews to build a full picture of their reliability.

5. How do you handle scheduling and missed visits?

Because commercial work is usually recurring, understand the logistics. How far in advance are visits scheduled? What happens if weather forces a reschedule? How much notice do they give? Reliable providers have clear answers and a system for keeping your cadence on track.

6. How is pricing structured, and what could change it?

Ask how they arrive at a quote and what factors might alter it — additional glass, harder-than-expected access, or added interior work. You want transparency, not surprises on the invoice. A good provider quotes after walking your property so the estimate reflects the actual job. Expect a qualitative discussion tied to your building rather than a flat number sight-unseen.

7. What safety practices do you follow?

Especially for any elevated work, ask how they protect their crew, your building, and the public below. Reputable providers can describe their fall-protection systems, equipment inspections, and site-assessment routines. A confident, specific answer signals a company that takes safety seriously; a dismissive one is a red flag.

Using the answers

Run every candidate through the same seven questions and compare their responses side by side. The strongest provider won't necessarily be the cheapest — it'll be the one that's properly insured, equipped for your building, transparent about scope and pricing, well-referenced, and serious about safety.

Because these providers come to your site, invite your top candidates for a walkthrough and ask these questions in person. How they respond — and how prepared they are — often tells you as much as the answers themselves. Browse providers in your city to start building your shortlist.