Phipps Houses, which owns and operates thousands of units of affordable housing in New York City is New York Citys oldest and largest non-profit developer of affordable housing. Founded in 1905 by real estate scion Henry Phipps (who donated $1 million to boost housing for low- and middle-income New Yorkers), the nonprofits first housing was at 321-337 East 31st Street. Phipps Houses has since grown to work in all five boroughs, offering staff housing for New York Hospital in the 1950s and building senior living facilities in the Bronx in the following decades. The nonprofit expanded significantly during the 1970s, building more than 2000 units of affordable housing and creating Phipps Neighborhoods, its community development and educational arm. The firm also operates through its subsidiary Phipps Houses Services. While much of the non-profits work is done managing housing, it still develops affordable housing, such as a new mixed-income project in Kips Bay in 2014 and joining with Related Companies to build greener affordable housing structures in Manhattan. It also has plans to develop affordable housing in Sunnyside, Queens.