architectural conservation
The process of maintaining and/or repairing the materials of a building or structure to reduce or reverse physical deterioration; based on a philosophy of conserving rather than replacing existing architectural elements; sometimes uses scientific diagnostic techniques developed by museum conservators and other researchers; examples include cleaning wallpaper, reattaching loose plaster, repointing masonry joints, and consolidating decayed wood. See also maintenance, restoration. (Bucher, 1996)