Had a head office like this once, done it for years, and still do it.
Turned up for the bi-monthly clean, usually a doddle and proceeded to go into robot mode.
Poled all windows twice across rinsed and then went inside (we are talking 2hours worth of poling here)
Got inside and 1st window was a mess and 2nd and 3rd nearly every window was smeared.
Asked facilities manager if anyone had been at the windows recently and he replied, "Oh yes we had the windows serviced just the other day and they oiled all the hinges etc with WD40, don't they work a treat now!"
I got the ladders off and spent the next 4 hours going over every window with the old fairy and squodge.
Moral, check as you go.
Hope they come up OK.