wide by 27 feet deep. The basement and first floor have a limestone facade, while the upper floors are brick with heavy limestone trim. The house includes a staircase connecting five of the floors, as well as "gold-leaf trimmed fixtures and intricate friezes". The roof has red tiling with copper and features two towers. The mansion has a private staircase on the top floor that leads to a rooftop balcony. The builders put closets in the same location on every floor to facilitate the possible future installation of an elevator. See also List of New York City Designated Landmarks in Manhattan from 59th to 110th Streets National Register of Historic Places listings in Manhattan from 59th to 110th Streets References External links Duke family residences Houses on the National Register of Historic Places in Manhattan Beaux-Arts architecture in New York City Houses completed in 1899 Houses in Manhattan Upper East Side Fifth Avenue New York City Designated Landmarks in Manhattan Gilded Age mansions