In specially designated areas or for designated buildings, the act of demolition without planning consent is enforceable under planning rules
. The consequences are usually hefty fines, and you would be liable if involved in any way.
This is true of conservation areas if the house is more than 115m³, and for many listed buildings. If the building is listed. You will need listed buildings consent rather than planning permission. The Planning Portal website contains more information about permission for this type of work. If you’re unsure of the status of your building or area, consult one of their guides.
As a result of this self-builders looking to demolish and rebuild a house on a site they own need to word their planning applications very clearly. The phrase 'Demolition of existing dwelling and construction of new dwelling' would make the full plan clear during the application process.
You will also need to notify building control of your plans to demolish a house. This is because demolition sites can be incredibly dangerous places. You should serve a Section 80 Notice to the local authority building control department. Which can be arranged with private, approved inspectors. You’ll need to give six weeks’ notice before you intend to demolish. You should receive a Section 81 agreement notice before this date.