Yes, inclusion on the Statutory List does not necessarily prevent alteration or extension, although Listed Building Consent will also be required, in addition to normal planning permission.

It is generally possible to find satisfactory ways to make additions or alterations, with specialist and/or professional advice and guidance. This work requires great skill and care in order to conserve the historic features, character and setting of the building. If you wish to carry out such works you are strongly recommended to contact one of the regional professional bodies to find a consultant specialising in historic building work.