Posted: 18/09/2014 at 12:26
It may be worth checking with your solicitor who owns the boundary between you and your neighbour: it will be in the deeds to your property. If the boundary is yours then the fence is legally yours irrespective of who erected it. We have had excellent neighbours for the past 47 years. The fence between us was always "ramshackle" 1st chain link wire but she then replaced it with home made slats from builders pallets which she got a friend to make. It lasted a few years but eventually began to fall apart and we knew she didn't have the money to do anything about it so I offered to replace the fence and pay for it, which she very gladly accepted so now we have a nice fence just 5ft high & good quality. I am under no illusions though, the boundary is (was) hers - (she, (June) died about 3years ago but stipulated in her will that her lodger could stay there for the rest of his days), so although I paid for it, when our now elderly neighbour goes and June's son sells the property any new neighbour can legally do what they like with the fence so long as a proper boundary partition is left in place.
Why I say this is, if the boundary legally belongs to you then you can affix anything you like to it so long as you stay within legal limits; irrespective as to who built it.
If the boundary is theirs then having a pergola (say 8ft high) on your side and growing something like a wisteria over it will give you the pleasure of attractive screening with a plant that will hold the pergola firmly to the ground even if it is free standing (though it will take a few years to be robust & strong enough to do that).
Good advice though has already been given regarding not making an enemy of your neighbour as no one wins in that scenario. John H