Penn South is the common name for the Mutual Redevelopment Houses, a limited-equity housing cooperative development located between Eighth and Ninth Avenues and West 23rd and 29th Streets, in the Chelsea neighborhood of Manhattan, New York City. The 10-building. 2,820-unit complex was built in 1962, and was sponsored by the International Ladies' Garment Workers Union based on the cooperative model promoted by the United Housing Foundation. It was designed by Herman Jessor.