Since publication of the groundbreaking Encyclopedia of Housing in 1998, many issues have assumed special prominence within this field and, indeed, within the global economy. For instance, the global economic meltdown was spurred in large part by the worst subprime mortgage crisis we've seen in our history. On a more positive note, the sustainability movement and "green" development has picked up considerable steam and, given the priorities and initiatives of the current U.S. administration, this will only grow in importance, and increased attention has been given in recent years to the topic of indoor air quality. Within the past decade, as well, the Baby Boom Generation began its march into retirement and senior citizenship, which will have increasingly broad implications for retirement communities and housing, assisted living facilities, aging in place, livable communities, universal design, and the like. Finally, within the last twelve years an emerging generation of young scholars has been making significant contributions to the field. For all these reasons and more, we are pleased to present a significantly updated and expanded Second Edition of the Encyclopedia of Housing.