seriously I can't bothered listing all the reasons its a bad idea as I replied to this about 20 times in the last year
It's not a bad idea, it's a good idea handled badly.
Look at taxi licensing, you still get dodgy minicab drivers but because the public are on the most part aware of the licensing law the sensible ones will avoid the dodgers or at the very least can make an informed decision. If someone is willing to pay an idiot who is driving around holding their ladder through their sunroof, then idiots will continue to drive around holding their ladder through their sunroof. No licence will stop that but would you really want that persons custom anyway?
If a similar licensing law was introduced and a) made national 2) enforced and d) the public were made aware of it, it could work.
Not necessarily saying it would work for every window cleaner everywhere but it would be an improvement to the half arsed attempt up we have here and the.. well.. nothing that they have down there.
A step in the right direction perhaps?