The built environment, which includes not only buildings but infrastructure, mediates several important climate impacts on public health and is also subject to diverse legal requirements. It is a subject of particular focus for policy efforts aimed at promoting adaptive responses to climate change on the part of institutions and individuals. This chapter presents key examples of public health impacts that arise from climate change but are mediated – possibly mitigated, possibly exacerbated – by elements of the built environment. It also describes the process and substance of adaptive responses to those impacts. Having presented these physical and policy contexts in its first section, this chapter’s second section considers the role the law could play as individuals, organizations, and localities react to climate-driven harms and seek to adapt.