This radical book aims to inject new insight and urgency into the discourse on the retrofitting of commercial and residential buildings in the face of the climate emergency. It is about the why, how and who should take the lead in revolutionising buildings in the face of serious climate and social change.Buildings contribute very significantly to the output of carbon, particularly in developed countries where the stock is old, but it is neither feasible nor desirable to demolish them all and start again! If existing buildings cannot in be replaced in the short-term by new zero carbon stock, retrofitting and adaptation of the existing building stock is critical and urgent. This book explains why and how the improvement of buildings requires a complex, holistic approach that brings all stakeholders together with respect and understanding. Yet to do this against a limited time frame is challenging. The book analyses what must be done, explores how it could be achieved and sets out a manifesto for action by all those engaged: from policy makers, to educationalists, designers, constructors, investors, funders and occupiers. By bringing together authors from across the built environment disciplines, the book stimulates debate within policy, practice and education circles which must lead to action if we are to avoid catastrophe. This is a unique addition to the literature on the sustainability of existing buildings and their retrofitting for the benefit of all.