Owners of old houses who wish to restore them are warned against proceeding before thorough research in documents and in the identification of fabric of the building. There are dangers in removing later additions and of destroying evidence in other ways. Methods of preserving, repairing and consolidating original materials are noted. The harmful results of sandblasting and the use of mortar stronger than the original brick or stone are explained. Included is a short bibliography, but reading does not replace the need to consult experts. -- AATA