This is an interesting article from the Telegraph about a property developer who demolished a pub in Battersea without planning consent. He applied for consent after the demolition had been completed and was refused that consent.
He now has the considerable costs of trying to reinstate the original pub with original materials.
Planning permission is not always required for demolition works but you may need that consent for demolition in a conservation area. This property was located in a conservation area. You may also need listed building consent to demolish a listed building. The easiest way to deal with such questions is probably to speak with the local planning authority before you carry out the works.
Developer ordered to rebuild historic pub after demolishing it without planning permission. Udhyam Amin was accused of trying to get planning permission 'by the back door' after pulling down the Alchemist pub in Battersea. Udhyam Amin reportedly had plans to extend it and build a block of flats on the site of the pub. A property developer who demolished a Victorian pub before getting planning permission has been ordered to rebuild it brick by brick. Udhyam Amin demolished the Alchemist pub in Battersea, south west London, and reportedly had plans to extend it and build a block of flats.