The Decker Building is a commercial building located at 33 Union Square West in Manhattan, New York City. The structure was completed in 1892 for the Decker Brothers piano company, and designed by John H. Edelmann. From 1968 to 1973, it served as the location of the artist Andy Warhol's studio, The Factory. The Decker Building was designated a New York City landmark in 1988, and was added to the National Register of Historic Places in 2003.