I run a restaurant with a big storefront

For a storefront on a busy avenue, every two weeks keeps it presentable and monthly is the absolute floor before customers start noticing. Traffic film builds up faster than most owners expect. Price is driven by glass area rather than time, so have someone actually look at the frontage instead of quoting off a photo. Cleaning Chief does commercial window cleaning on a fixed schedule and works early mornings, which matters when you cannot have a ladder in the doorway during service. Ask about the frames and the door glass too. Spotless windows above a filthy frame somehow look worse than leaving the whole thing alone.