I have the same problem the bungalow in the field at the back of our house is surrounded by lleylandii. They must be 25' tall he has trimmed his side of the trees but not ours, it would mean he has to come into the gardens to do that and pick up the branches. I have mentioned it to him but he has completely ignored it, although he said he hadn't realized how tall they were from my side. I thought there was some legislation about that but I'm not sure how to go about it.