if you cleaned them while they were doing Groundworks, Sthill saws out, DUST everywhere, cutting Paving slabs. They will have been a WASTE of time, all the dust from the paving being cut would have rested on the water on their windows, they would actually been crap. Keep well away if work near like this. keep your ustomers happy. how would you like to find a docket saying your windows have been cleaned, to see they are full of dirty dust.
Be Proffesional, even in window cleaning. Your customers are your living. Thers lots of us about.