The best answer is always PREVENTION! You can easily prevent the need to remove remove paint from windows by covering, or having your painting contractor cover your interior and exterior glass in plastic.
Paints and stains are corrosive to glass… And, if left long enough on window glass, can cause permanent staining. Also,’Hard Water Stains’ can occur immediately after your building’s exterior is painted or stained. Hard water stains are caused by rain water running over prefabricated surfaces, leaching hard minerals and acids from that surface and depositing them on windows below. In the case of new paint…
…. Damaging stains can occur immediately after the first rainfall.
The need for a complete exterior window clean is a must to prevent glass degradation. The use of proper window cleaning techniques will neutralize the P.H. of the glass and effectively stop the corrosive property of hard water stains caused by new paint.