I almost always clean all of the entire window, that said there are exceptions, care really does have to be taken with vents in the top of the frames of course, and you also have to watch out for oxidized frames too.
If a frame is oxidized you can still get away with doing the frame...to a point!
Spend too long washing it and you will get spotting.
First time clean on frames that have oxidized I really THOROUGHLY wash them, on maintenance cleans they get the briefest of touches, and then I will concentrate on the glass...I always clean the sills though.
I will always check the windows for oxidization on a first clean.
Time taken on your average 3 bed semi for a repeat clean???
Houses vary of course, I do one with very easy access (a stand alone account) that I can do in 8 minutes, thats from opening the back door of the van to closing the drivers door on completion. That's 9 windows and 2 doors, all UPVC and everything, frames and doors washed too.
On this particular run the next 2 houses are also 3 bed semi's, 10 windows this time, 1 large patio door, a kitchen door and a large front door area.
Both houses identical and the pair take me about 25 minutes...er, that is for the pair, I pull up at the one and both are done without need to move van.But access to these two is more awkward, flower pots, plants, not much room to manoeuvre and so on.
By and large a straight forward 3 bed semi should take somewhere around the ten minute mark, plus or minus 2 or 3 minutes, and, providing the frames are in good condition they will also be included in that time.
Having said that, cleaning at that pace and to a good standard takes practice and experience.
Done trad, a similar property will take you about 5 minutes longer.
On standard semi's the time saving isn't great, although for the trad window cleaner to also wash down all of the frames and doors it will take him longer again.
But for any newbies reading this.....don't price for work on the belief you will do anything up to 6 houses an hour!!!! It won't happen!
Ian