Posted: 19/11/2017 at 17:17
With only a foot and a half of space between the two houses, there will not be room for a wall, as the footings would be need to be on their half as well.
Instead, the easiest option as someone else has suggested, is a trellis fence, with the posts on your side, on which you could grow something like an evergreen climber, which could be trained sideways along the fence. I would also think about redoing the front path as a dogleg outside your front door and then going diagonally across your front garden which would take you physically away from your neighbours a bit. You could then plant slightly taller plants in the triangle nearest to them. What I would say is don't get all uptight about the 18" of ground which is on your side, it's not just worth the hassle and unpleasant neighbours could get even worse.