Improving energy efficiency in buildings is central to combating climate change, with more than a third of U.S. greenhouse gas emissions coming from the building sector. Over the past year, there has been a much stronger push from the federal level to fund energy efficiency programs as part of a national agenda to foster a clean energy economy that generates sustainable high-quality jobs and reduces our dependence on imported fossil fuels. Vital to this process is to develop innovative financing solutions that reach broadly across energy efficiency and low-carbon energy options. Energy Financing Districts (a.k.a Property-Assessed Clean Energy (PACE), Sustainable Energy Financing, Clean Energy Assessment Districts (CEAD), Contractual Assessments, or Special Tax Districts) were first proposed by the City of Berkeley, California in 2007 and have received increasing attention as a mechanism for financing residential or commercial clean energy projects, including energy efficiency, solar photovoltaic, or solar thermal systems. EFD’s represent one specific and powerful example of an intellectual innovation that is broadly applicable to fostering a profitable transition to a clean energy economy at the local, regional, national, and global levels.