Yer, that's pretty quick but some of the glass looks like it's being missed at the bottom of the pane and in the corners. Fair enough if the glass is practically clean anyway but a lot of it is getting one brush stroke only. I can't clean like that at the moment I'm still scrubbing out spiders nests and scrubbing storm debris off. Once the snails wake up again things will be different too.
Hi Dave, there was no glass missed

that was a 4 weekly clean so glass
wouldn't be particularly dirty but as a rule of thumb 2 max 3 times longer on
first cleans, spiders nests takes a flick/swipe with the brush Imo, bird muck
for me is the only issue but a few taps of the brush usually takes care of that
if not leave to soak while doing the rest of the windows and return to it where 9/10
times it comes off with ease. Not sure about storm debris thankfully but did a new
estate where for months every time we went there was thick black soot over all windows
and frames we used to quickly go over all windows then go back over we found this the
quickest way to clean it off.
The hardest thing is learning other people to work efficiently for example a guy
who was working with us not so long ago who was a good worker, fast, reliable,
he was keeping up with the other boys after a few weeks but complaints were
coming thick and fast, I kept taking him through the process, telling him to slow down
but for what ever reason we kept getting complaints water marks, snail trails, webs ect.
He got another job and complaints stopped, I think the most important thing is to check
window for snail trail, bird muck, webs ect before wetting window which takes 1-2 seconds
on approach sometimes you don't see these things while cleaning.