We bought out house 14 years ago with a leanto attached to our neighbour's side wall. The current roof covering of the leanto is corrugated plastic and slopes down to a gutter which is attached to a large beam of wood attached to the neighbour's house. The plastic roof leaks in a few places and needs replacing. We haven't had any problems so far with the neighbours (we are friendly with the tenants and have only met the owner once). We don't think the leanto is causing him any problems but would like to know if he owner can ever make us take the leanto down as it is attached to his wall. We know that the leanto has been there at least 18 years and may have been constructed just after the second world war though have no proof of that.