If the repairs are minor repairs, such as replacing roofing tiles with the same type and weight, replacing floorboards, or re-pointing brickwork etc, then the Building Regulations will not be required. However, if the repairs are more significant, such as removing part of a wall and rebuilding it, or replacing roofing tiles with a different, substantially heavier type of tile, or thatching, then the Building Regulations will apply. If you are still not sure or require further information please contact the Building Control Officer for your area.
Other issues to consider:
You may need to obtain other permissions for the work you intend to carry out such as Planning Permission, Listed Building Consent, or Conservation Area Consent and you should contact the Council's Development Control Team in respect of these matters (01884 234260/234262) or email email@example.com
There may be a restrictive covenant on the property which requires you to obtain the express permission of a previous owner before carrying out any work. The Party Wall Act may also apply to the work. Your legal advisor may be able to help you in respect of these matters.