The American Psychological Association (APA) is the largest scientific and professional organization representing psychology in the United States. APA is the world's largest association of psychologists, with nearly 130,000 researchers, educators, clinicians, consultants and students as its members. Their mission is to advance the creation, communication and application of psychological knowledge to benefit society and improve people's lives.

In an effort to reduce energy consumption, maximize recycling and contribute to a healthier environment, in April 2014 a second greenroof was added to APA properties at their headquarters at 750 First Street. NE, Washington, DC., which qualified for the DDOE grant program (see below). The first greenroof was constructed in 2008 at their commercial rental property at 10 G Street, N.E. - see the Project Profile in The Greenroof Greenwall Projects Database. In 2012, the Environmental Protection Agency rated both buildings in the top 10 percent of buildings in the United States with the lowest carbon footprint. In addition, APA purchased a utilities plan that uses 100 percent wind energy and significantly reduces APA's carbon dioxide emissions for both buildings.