Washington, D.C. has quickly become a pioneer for environmental sustainability. The new Nationals stadium, for example, is the first baseball stadium in the country to receive LEED certification. Certification for LEED, which stands for Leadership in Energy and Environmental Design, is given by the U.S. Green Building Council, when buildings qualify for a certain number of points in five categories: sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality.

The District already broke new ground when it became the first major city to require LEED certification on all new public and private buildings under the Green Building Act of 2006. The new rules begain applying to building plans submitted to the city on January 1, 2008. Other large cities have implemented similiar, but more lax rules, such as New York City and Boston, which require LEED certification, but only on public buildings. Even before the D.C. law was proposed, the National Association of Realtors headquarters became the first LEED certified building in the city when it was completed in 2004.