This thesis is a study that chronicles Penn South's history of affordability and social responsibility, and offers possible strategies and partners for maintaining affordability through preservation. A majority of the thesis is devoted to the various financing methods that the Mutual Redevelopment Houses, Inc. Board undertook, and the various strategies that helped the cooperative to remain affordable. It also deals with the multitude of misadventures with equipment, labor, and etc. that caused the project to run over budget. With collaboration between Penn South's tenants, administration, creditors, and the New York City government, though, the cooperative has been able to provide over 2,800 affordable units for over fifty years. Lastly, the thesis seeks to offer possible partners and methods of retaining affordability. The majority of this thesis' data was gathered from the Kheel Archives at Cornell University, which houses a spectrum of garment union documents and correspondence. Other information was gathered directly from Penn South administrators or from secondary affordable housing and preservation sources, particularly sources that dealt with New York City and New York State.