Pratt soon outgrew this residence and moved again to the 1027 Fifth Avenue, a 40 ft. wide residence that was the central of three Beaux-Arts mansions at 84th and Fifth Avenue. Their neighbors included Florence Adele Vanderbilt Twombly at 1028 Fifth Avenue. In 1936, a year after his wife's death, he sold 1027 Fifth Avenue to the Marymount School, who had owned Mrs. Twombly's home since 1926, and combined the building with its neighbors but preserved all the exteriors and much of the interiors.