I am an approved council sub contracter albeit not window cleaning side of things, this is the only documentation accident wise I carry which is mandatory anyway even for a one man operation don't adsk me why, have a look on the web under health and saftey every thing you need is on this site. There are council departments who will assist you in anything you require health and saftey wise, I have the council h@s officer checking my van about twice a year, he looks for safe working practises like fire fighting appliensess etc etc. Risk assesments are not as complicated as everyone makes out, only my opinion but the saying you can't teach common sence springs to mind, all the best.
Malky