Design has historically been employed in service to expanding industrial production and consumer culture – perhaps it is no wonder that design has often been seen as part of the problem within sustainability discourse. Sustainability requires fundamentally rethinking the organization of everyday life in terms such as ecological complexity, social responsibility and risky futures. A role for design in this is to question the status quo, to critically reframe the issues at hand by materializing alternatives within the here and now. Such a role for design increases its agency within social processes, in which the materials and methods of design mobilize critical reflection and influence public discourse. Critical practices of design do not produce the traditional ‘objects’ of design, intended to be built or lived in, industrially produced or mass-consumed – though such practices are deeply rooted in design skills, processes and materiality. Such practices practices provide vivid reformulations – and urgently needed visions – of what design could be and what society could look like. This book embodies our inquiry as the story of SWITCH!, a design research program carried out since 2008 by an international team of designers, artists, architects, computer and social scientists at the Interactive Institute in Sweden. This chapter, ‘Explanation’, discusses the contexts and motivations for this work, along with the research themes ‘energy ecologies’ and ‘critical practices’. The project set-up and contributors are also described.