I do a rugby club which is surrounded by trees just like the building in the pic. its done every 2 months and on one side nearest the trees it gets absolutely minging.
I havnt done the windows since feb because of covid , tho I am resuming in august... it is going to take me twice as long just like a first clean.
as for the care home ..... where I live I think £150 would be about right.
because of the trees and cars , I would set aside 3 HOURS. I would probably do it on a sunday morning when its quiter.
I also only take on these types of jobs if I get paid on completion.
of course different parts of the country would command a better price ....