Ennead Architects, formerly known as Polshek Partnership Architects, is a New York City-based architecture firm founded in 1963. Ennead also offers master planning, historic preservation, and interior design services. It specializes in designing the buildings that house government and cultural institutions, but also residential high-rise condominiums and hotels. The firms best-known hotel is The Standard at 848 Washington Street, developed by André Balazs and opened in January 2009. Ennead Architects also designed the Ritz-Carlton Downtown at 10 West Street in Battery Park City, a condo-hotel hybrid with 150 apartments above more than 300 hotel rooms; and the 258-unit Riverhouse condo in Battery Park City. Ennead has worked on projects for cultural institutions in New York, including the Brooklyn Museum, the expansion of the Museum of the City of New York, the Rose Center at the Museum of Natural History, and Carnegie Hall. -TA