Normally you'd need planning permission, yes, although some local authorities have a policy of allowing them without. If it blocked light to a basement flat then there may well be issues of interference with a right of light, yep. Rights of lights are an exception to the general rule that lessees can't acquire prescriptive easements against the lessor.
Normally you'd need planning permission, yes, although some local authorities have a policy of allowing them without. If it blocked light to a basement flat then there may well be issues of interference with a right of light, yep. Rights of lights are an exception to the general rule that lessees can't acquire prescriptive easements against the lessor.