Conservation eorts to preserve modernist architectures were advanced by the establishment of regional, national, and international organizations devoted to saving this Cultural Heritage.Bringing together areas of architectural documentation and the conservation communities research on typical technical issues preventing the rehabilitation of historic structures is still in its early stages. Researchers and conservation experts may collaborate, and have better access than ever to rst-hand information about the motivations behind an intervention and methods used in the creation of places.Though, there are still several diculties despite a sizable amount of professional attention and an amazing corpus of conservation expertise.This book explores possible methodology of analyses of 20th century modernist architecture in Brazil, an assessment that cannot be completely exhaustive in describing these complicated buildings as they are sometimes dicult to be interpreted.Furthermore, the scarce sources available, part of the which are unfortunately disappearing in old archives, are sometimes kept alive only thanks to the determination of the descendants of some architects willing to preserve the memory of the works designed by their relatives.The works of Oscar Niemeyer, Vilanova Artigas, Roberto Loeb, Lina Bo Bardi (both built and unbuilt) investigated and documented in this book show the vision of these Master of Architecture, their posture as designer in the relationship between architecture, technique, and construction and the fundamental concepts that guided their design strategies.Experimentation with novel spatial concepts and technology advancements resulted in a character that was revolutionary, particularly regarding the role of structure in dening architecture, the nationalist spirit, and the valuing of communal and human spaces along the 20th century in Brazil.