Hi
The SPIF, the form that you have to fill in, clearly states that any discussions with a neighbour, which may affect your property will have to be declared. Furthermore, if you have made any complaints to the neighbours, or any relevant authorities these too must be disclosed.
These issues are becoming very topical at the moment and there have been a few court cases surrounding the non-disclosure of information. The SPIF does not contain examples of such behaviour or any cut off point when you dont need to declare because the problem has been rectified.
However, the ball-park figure that tends to be used is 2 years, so, if you have had no problems in 2 years then it will be seen to be rectified.
The best thing you can do is see a conveyancer or a property solicitor, who will advise you if you do have anything to declare, and if you do, how to word it.
Jo