North Somerset is a unitary authority in the ceremonial county of Somerset, England. In the United Kingdom, the term listed building refers to a building or other structure officially designated as being of special architectural, historical or cultural significance; Grade I structures are those considered to be "buildings of exceptional interest". Listing was begun by a provision in the Town and Country Planning Act 1947. Once listed, severe restrictions are imposed on the modifications allowed to a building's structure or its fittings. In England, the authority for listing under the Planning (Listed Buildings and Conservation Areas) Act 1990 rests with Historic England, a non-departmental public body sponsored by the Department for Culture, Media and Sport; local authorities have a respon