Green building has emerged over the past decade as a robust movement to create high-performance, energy-efficient structures that improve occupant comfort and well-being while minimizing environmental impacts. Supported by organizations such as the U.S. Green Building Council and its Leadership in Energy and Environmental Design (LEED) standards, both public and private entities are increasingly pursuing green buildings in the institutional, and commercial. Over the past decade, there has been a virtual explosion of activity in the green building field. While the goals of green building are easy to embrace in concept – resource efficiency, habitat conservation, improved occupant health, better pedestrian environments, and a commitment to high-quality buildings – they are more difficult to achieve in practice, especially in affordable housing. Many colleagues in the affordable housing world are sensitive to the environmental and community impacts of development but feel that their work is already too difficult to afford the luxury of addressing green building concerns. A precious few see housing affordability, sprawl, indoor environmental quality, loss of habitat, loss of community character, and resource and material waste as a set of interconnected problems calling out for more comprehensive solutions. Many of those colleagues have managed to conceive of green projects and sometimes even build them, but this has presented a new set of problems. The current affordable housing finance system, characterized by a focus on initial capital costs, cost caps, and other regulatory and fi nancing constraints, often impedes the realization of the benefits of green building.