I've done triple storey flats from a ladder before. It was a regular job. I stopped doing it about 1999/2000. My understanding was that the law changed to outlaw this even before the big WAHD change in 2005. Mind you, I drew the line when someone from a block across the road wanted me to set up my ladder on top of a garage roof to reach her top floor windows. She was really miffed too when I refused.