[neom]

For those of you who also have no clue what a Grade II* is, it appears to be a protected status of buildings in the UK - In the UK, listed buildings are graded according to their historic and architectural importance: Grade I: Buildings of exceptional interest (about 2.5% of listings) Grade II*: Particularly important buildings of more than special interest (about 5.5% of listings) Grade II: Buildings of special interest (about 92% of listings) - Thorne Island Fort is classified as "Grade II*" (Grade Two Star) so apparently it's considered particularly important and of more than just special interest.

[pm215]

In particular listed buildings are subject to special planning rules and need permission for any extension, alteration or deletion; the planning authorities can mandate that you do any alterations in particular ways (e.g. use of traditional materials) to avoid damaging the character of the building. This means that everything is more expensive and takes longer. Luckily in this case the current owner seems to have done all that hard work already...