The renovation and rehabilitation of existing constructions together with the preservation and restoration of the architectural heritage are, in fact, activities which deserve particular attention by people involved in both design and constructional process. This wide subject has been treated in the book by identifying the main aspects and analysing them from the general design criteria to the execution rules in order to completely cover the concerned field. This approach is, therefore, characterised by an unitary feature which is difficult to find in other books. In particular many practical examples collected from all over the World are analysed, compared and discussed in detail, focusing the main reasons of both the structural choice and the material selection. The authors of the 6 Chapters, as out-standing experts in their specific fields, provide high level contributions particular based on their technical and professional experience.