Over a number of years, research released through a series of publications known as the Manuali del recupero (“Restoration Manuals”, for Rome 1989, 1997; Città di Castello 1990, 1992, Palermo 1997), together with other parallel initiatives, has presented an integrated vision of the arts of pre-modern construction. Just slightly more than 20 years ago, pre-modern building materials seemed untrustworthy to conservation and restoration professionals. The technology linked to these materials and the historic construction values themselves were perceived as a dying culture, unsuited not only to keeping pace with modern technological performance, but also inadvisable for conservation and restoration operations for historic built heritage. By brin...