The call for climate action is necessitated by the severe impacts of this global change on both environmental health and human life. This chapter outlines the raison d’être of the book by introducing the central problem that underpins its narrative and framing it as a super wicked problem. The problem of climate change has been conceptualized as one that is complex, urgent, and resistant to straightforward solutions. The chapter situates the problem within its broader context, highlighting the intersecting challenges of rapid urbanization and persistent economic constraints. The discussion then turns to the conceptual foundation of the book, which draws on socio-technical systems thinking. In this regard, both technical solutions and social solutions are examined, with an emphasis on how they must co-evolve to address the integrated and multi-dimensional nature of the challenge. The overarching objective is to advance the decarbonization of the building energy sector by focusing on the demand side. Finally, the chapter delineates the scope and areas explored in the subsequent chapters, providing a structured roadmap for the discourse that follows.