Hello great outdoors
Are you suggesting leave machine in van, and buy another 50m of hose, I already have 3 x 25m, the machine would be about 100m below me,and about 20-30m into the roof. I suppose thinking about it, it would be like being in a cherry picker, in theory.
Yes simple, I assumed there was a good reason for not leaving it with the van, simply run HP hoses any decent machine will cope easily 5 floors no prob as long as its not 7ltr machine 
Be careful where the connections are ie windows blah blah as the hose will move on start up blah blah
Forget messing with booster pumps and carrying up the water
Damn that could be considered as advice 
Thanks great outdoors,
Advise is what this forum is all about,
I tried uploading pics but it's having none of it.
I can park my van at the side of building no probs and have and my machine running from van, this is perfect solution. My machine is probably capable, and there are no windows on this side of the building, I use quick release connections, so it would be a case of connecting enough hose to go up the side of building, drop a rope off roof and tie to hose and pull up, make some kind off loop around a post on roof to take the pulling away from me, and go to work.
Thanks mate,