The word conservation, when used in the context of the preservation of built heritage, implies an intrinsically complex concept that evolved over time, since it has been influenced by the perception of history throughout time. This volume emphasises why an understanding of the cultural evolution of the conservation approach must be considered a prerequisite for architects and engineers if they are to cooperate in full harmony with historic-artistic culture for the preservation of global built heritage. In particular, the volume highlights how, during the second half of the last century, the preservation process also involved engineering - the science of making practical applications of knowledge - which, for a long time, made an uncritical use of techniques and materials and devised interventions on historical heritage that were heavily invasive. The volume also devotes special attention to the problems related to seismic risk, to which Italy, Greece and Portugal are particularly prone. Problems that emerge during the crisis and reconstruction phases are dealt with in detail, as is scheduled maintenance, as this latter approach always constitutes an improvement in the performance of the monument and is the most appropriate tool for the conservation of the built heritage. Finally, the volume collects examples of building restoration with case studies of many outstanding monuments. The work will appeal to professionals and academics in the broader fields of civil engineering (both geotechnical and structural engineering), architecture, art history, the history of architecture, restoration and cultural heritage management. This book will: Provide a critical reading of the history of conservation; Discuss materials and techniques of ancient architecture; Cover seismic vulnerability and preservation of the historic integrity of the monument; Advocate an approach based on programmed maintenance; Feature numerous case histories, including St Mark's Basilica in Venice and the complex restoration of the cathedral of Notre-Dame in Paris.