Define the panes and components
List internal and external glass, frames, sills, tracks, screens, glazing type, height and access restrictions. Note whether the site is a home, business, strata building or high-rise property.
Assess access and safety
Ask how each provider will reach the windows and what equipment, training, approvals and current insurance apply to the method. High-access, roof, rope or platform work requires site-specific controls. Do not lean out or use unsafe ladders.
Compare products and techniques
Check whether products suit glass coatings and nearby frames or finishes. Confirm weather arrangements, water use, exclusions, restoration work and the quote basis. Scratches, etching, failed seals and hard-water damage may not be removable through routine cleaning.
Maintain realistic expectations
Reviews can help inform research but do not guarantee results. Ask what is included, who will attend, how missed tasks are handled and whether screens or tracks are extra. Cleaning cannot guarantee streak-free glass in every condition.
