A listed building is a building that has been placed on the Statutory List of Buildings of Special Architectural or Historic Interest. A listed building may not be demolished, extended, or altered without special permission from the local planning authority, which typically consults the relevant central government agency, particularly for significant alterations to the more notable listed buildings. Owners of listed buildings are, in some circumstances, compelled to repair and maintain them and can face criminal prosecution if they fail to do so or if they perform unauthorised alterations.