1800 Massachusetts Avenue is a 190,000 square foot building located one block east of Dupont Circle and is LEED (Leadership in Energy and Environmental Design) Gold Certified.  The newly renovated building features a state-of-the-art conference center on floors one and two, a fitness facility on the lower level and retail on the first floor. It serves as the Washington headquarters building for the Service Employee International Union (SEIU).  Joining SEIU at 1800 Massachusetts are the United Nations Foundation and the Better World Campaign.

1800 Massachusetts Avenue is an ENERGY STAR partner.