My back garden seems to be 4ft longer than my neighbours’, but on a map of the area the gardens are all the same length. I’m only concerned about this because the council want to build at the back and may need the land. The garden has always been this way since I bought it and in the 25 years the previous owner lived here.
I think it’s unlikely that the council will want to fall out over 4ft of garden. You will be able to claim ownership of it in any case if you can prove that the land was part of the garden for more than 12 years prior to October 2003 (when the law on adverse possession changed). Ideally you would get signed statements to this effect from the previous owner and/or neighbours. But it’s unlikely to be necessary.