The number of U.S. counties with green building programs has increased almost 400% since 2003, says a report from the American Institute of Architects (AIA).
Additionally, some 14% of U.S. cities with populations of more than 50,000 have green building programs in place, with many more planning to follow soon. From 2003 to 2007, the number of cities with green building programs grew 418%, according to the report.
The study, "Local Leaders in Sustainability: Green Counties," found that the number of green counties among the 200 most populous counties in 2008 rose from just eight in 2003 to 39 today. More than 49,900,000 people live in counties with green building programs that were covered in the study.
The eastern region has the most green building programs - 19, affecting some 19 million people.
The central region has 7 programs that affect some 9 million people.
The mountain region has 3 programs, covering 2 million people.
The western region has 10 green building programs, with almost 13 million citizens affected.