If you use barbed or razor wire, under the Occupiers
Liability Act 1984 you must take reasonable precautions
to prevent injury to other people, including trespassers,
caused by dangers on your property. If you are building a wall
on the boundary with your neighbour, you may need your
neighbour’s permission (under the Party Wall Act 1996).
If you live somewhere, such as an estate, where there
are building restrictions in force, you may need to get
special permission.