From the OP's point of view, I think it's probably more important initially
to ensure that there has been no nibbling away of the actual boundary.
After that has been established is the time to discuss what kind of fencing
to put up. My daughter as just bought a house and is responsible for the
fencing on one side. Needless to say, after a huge cutting back of
overgrown shrubs we have discovered that it needs replacing! There don't
seem to be any height restrictions in the deeds of the property and her
neighbours would be delighted if she built an 8' brick wall! As it is,
she'll be putting in 6' larchlap panels and then perhaps putting trellis on
top of that. Wouldn't the deeds usually show any such restrictions, if they
exist?

Planning Permission will be necessary for the erection of a fence, wall,
gate or any other means of enclosure provided that:-

1) It would adjoin a road, alleyway or garage court used by vehicular
traffic and would be over 1 metre in height or would be over 2 metres
high elsewhere.


--
Kay
"Do not insult the crocodile until you have crossed the river"