Buildings are listed if they are considered to be of national architectural or historic interest.
A listed building will be included on the statutory list of buildings of special historic or architectural interest. This list is produced by the Secretary of State for Culture, Media and Sport, advised by Historic England. It includes around 11,000 buildings and other structures in Westminster.
Listed building consent is required for any works to a listed building that would affect its special architectural or historic interest.
This applies to all types of works and covers all parts of the building (interior and exterior). It may include works to attached or curtilage buildings.
It is a criminal offence to carry out works to a listed building without first obtaining consent from the council, even if you did not know that the building was listed.
If you are planning to carry out works to a listed building, you should seek pre-application advice to make sure you know which types of permission or consent are needed.
You can see the Westminster validation checklists here. These explain the information you need to submit with your application