For many years it has been recognized that improving the energy performance of the existing housing stock is vital if energy demand is to be reduced to combat climate change. The art of retrofit is posited as a way forward beyond today’s weak pseudo-Modern architecture, all that is left as the final echo of Modernism’s original utopian impulse. Central to the book is the presentation of domestic street by street retrofit as an issue with technical, financial, and societal dimensions. A holistic view of the complex, interacting factors that have held back any advance is interspersed with a historical account of retrofit’s faltering progress over the last twenty years. The crucial challenges that have been encountered are described, including the technological and human factors that urgently need to be addressed. It is suggested that the utopian instincts that propelled early modernism can be redeployed in finding an approach to retrofit that will pave the way towards a politically engaged architecture of social purpose. A Future for Retrofit’s goal is to involve the creative imagination of designers and form an alliance with policy makers and the many others in the business of urban improvement, it is intended for all these audiences.