This article presents an overview of green building economics and policies through a survey of theoretical and empirical evidence concerning green building practices. We define green building policy as policies that affect the entire life of the building, from design and construction to operation and deconstruction. We examine the economics of green buildings in the United States, with particular emphasis on market failures in the building sector such as information problems and externalities. We also discuss how policy instruments are used to address these market failures. We present original data on the types and potential impacts of these policy instruments in the United States, along with a brief review of international green building programs. We conclude by describing challenges for the empirical study of green buildings and priorities for future research and policy in this area.