<<The enforcement notice required the following step to be undertaken by 17th July 2006:- remove the present roof extension and form extension in accordance with with planning permission no.,,,,>>
So, there was Planning permission, for something, just NOT what he built ?
<<Upon review of this file, I note that there is no evidence to confirm either full compliance with the requirements of the notice or a subsequent planning permission approved for this development.>>
He has never submitted, in the intervening period, a Planning Application to try and keep what he built ?
Local Authorities give 'Conservation Area' status to designated areas for good reasons..........your fella should have sorted all this out *before* he started building.
He'll need to enter into serious negotiations with the council.........or arrange for the removal of the offending structure, I'm afraid.