Awareness of global warming and the extent of greenhouse gas emissions have focused more attention upon energy efficiency in building. Moreover, the inventory of "green" office space in the United States has increased dramatically since the introduction of rating schemes that attest to the energy efficiency or sustainability of commercial buildings. In some metropolitan areas, the supply of certified office buildings has more than doubled in the last decade, and there are a few metropolitan areas where "green" office space now accounts for more than a quarter of the total office stock. In this paper, we analyze the diffusion of buildings certified for energy efficiency across US property markets. Using a panel of 48 metropolitan areas obser...