Perhaps the most frequently asked question of all.
Your windows are going to start getting dirty soon after cleaning them,that’s why many commercial customers have us out monthly (in some cases even bi-weekly). So the question is really, how dirty do you want to let them get.
How close you are to trees and foliage, how clean or dirty is your brick or siding and what is your proximity to dust and dirt from the road or local construction. Your preference, mixed with the answer to those exterior questions, and a few other interior questions is the only way we know to provide a definitive answer to that question.
Most home owners are happy with once or twice a year but we have had residential customers set up regular maintenance schedules for as often as bi-monthly. The thing to keep in mind is that, cleanliness is not the only reason for cleaning your windows.
Hard water, calcium from mortar or precast concrete, aluminum oxidation from siding or frames and screenburn from metallic screens can all cause permanent damage to glass … for that reason, we recommend a frequency of at least twice annually to all customers … from that point, it is, as I say, a matter of degrees. If you want your windows to look anywhere from acceptable to excellent nearly all the time … you may want to consider a bi-monthly service.