Whilst it is a criminal offence to carry out unauthorised works to a listed building or a protected tree, it is not illegal or an offence to carry out a development or use that does not have proper planning permission. It is merely unauthorised and no criminal offence has been committed. Only when the Authority has served formal enforcement or similar notices, all avenues of appeal have been exhausted and time periods for compliance have expired, does the person responsible for the unauthorised use or development become liable to prosecution and, if found guilty, acquire a criminal record.
The person against whom an enforcement notice is served has rights of appeal which must be respected and this can result in some delay in securing a resolution of the matter.
The Authority can only use its enforcement powers effectively if there is sufficient robust evidence available to demonstrate clearly that a breach of planning control has occurred.