@Matt5 how would you deal with upstairs windows that I can't reach? I'm not good with heights & don't even like hubby up on the ladder to do them.
I connect a soft broom connected to the end of my swimming pool telescope leaf clearer. I use masking tape and quite a bit to keep broom secure.
Use the same method as ground floor windows.prepare a window cleaning concentrate ( even dish washing liquid) something that doesn't streak, in a rectangle bucket.
Hose windows down first probably with hose on jet spray.
Slowly sweep/brush with suds and hose down... window sills may have to be cleaned from in the rooms.
NB..You may get a little wet so wait for a nice warm day...Good luck !
That sounds reasonable for the lower windows, and maybe even the upper ones at the front, but we wouldn't be able to reach the back upper ones even with an extension unfortunately