It depends, on most of these types of property you can access the window from the side, failing that I can use my sl2 pole which can reach 60', I then attack the window, while being half way up their garden.
I also have a workbox that also can be used as a small step, it raises me up about a foot off the ground which sometimes is all you need.
Failing all of these methods, I just leave the window and don't charge them for it.