Tony, clematis comes to mind, so many varieties and the speed at which some grow is amazing!
you don't say what facing the wall is, which would make a difference to the type of climbers that would be happy there!
Non shedding leaves might be a bit of a problem, the only thing that comes to mind is ivy, and I'm afraid as pretty as it is, I wouldn't put it on any wall of mine! How about a jasmine?
DP