This Digest provides an overview of the principles of the conservation management of masonry in historic buildings. It discusses the legislative framework in the UK (including interactions with planning authorities and conservation bodies, and regional variations in conservation policy) and the general principles of conservation practice, including minimal intervention, protection against disaster and neglect, use of identical replacement materials or the nearest analogues, respecting the spirit of the core building, maintaining a log of works, and agreeing a protocol for project management before a project begins. The Digest then lists the recommended procedures for good conservation project management in a summarised form. Key events in the development of building conservation bodies, practice and legislation in the UK are listed chronologically in the Annex. 8 pages.