Listed buildings are those that have been protected by law from any changes to the building without Listed Building Consent. Usually, work to the windows and doors will always need consent as the effect of the work may not be easily determined.
If you are the owner of a Listed Building, contact your local authority for an application form for Listed Building Consent. It is advisable to get some advice from the conservation officer before applying as if your application is likely to be rejected, this could save you time and money.
English Heritage are always notified of applications for work on Listed Buildings and they usually contact further bodies to discuss the most important applications. Normally, buildings listed Grade I or Grade II are of outstanding national interest and these are the applications that are usually rejected, but those with Grade III are often granted consent.