He attended the École des Beaux-Arts-inspired atelier of Richard Morris Hunt in New York City, from 1859 to 1861, and again in 1865, following his military service.

1928), was a solo effort, but in 1867, he formed a partnership with Fraser, his former teacher, and George Hewitt, who had worked in the office of John Notman.

In 1897, Furness designed an addition to the Philadelphia Savings Fund Society (PSFS) 1869 building which has now been incorporated into the St. James, a high-rise luxury apartment complex in the city’s Washington Square neighborhood.

[1] Following Fraser's move to Washington, D.C., to become supervising architect for the U.S. Treasury Department, the two younger men formed a partnership in 1871, and soon won the design competition for the Pennsylvania Academy of the Fine Arts (1871–76).

His strong architectural will is seen in the unorthodox way he combined materials: stone, iron, glass, terra cotta, and brick.

One notable commission was the 1870–1871 redesign of the interiors of elder brother Horace Howard Furness's city house, at the southwest corner of 7th and Locust Streets in Philadelphia.

[6] Furness designed bookcases and a suite of table and armchairs for the boardroom of the Pennsylvania Academy of the Fine Arts in Philadelphia, along with the lectern for its auditorium.

[8] During the American Civil War, Furness served as captain and commander of Company F, 6th Pennsylvania Volunteer Cavalry, also known as "Rush's Lancers".

Citation: The President of the United States of America, in the name of Congress, takes pleasure in presenting the Medal of Honor to Captain (Cavalry) Frank Furness, United States Army, for extraordinary heroism on 12 June 1864, while serving with Company F, 6th Pennsylvania Cavalry, in action at Trevilian Station, Virginia.

This was most unfortunately demolished in the Philadelphia urban renewal campaign several years ago, but the gigantic and forceful scale of the granite membering alone should have justified its respectful preservation.

As Sullivan's Autobiography of an Idea testifies, the vitality and originality of Furness meant more to him than what he was taught at the Massachusetts Institute of Technology, or later at the Ecole des Beaux-Arts in Paris.

Frank Furness' Clearing House, now demolished like many of his best works in Philadelphia, contained an array of violent pressures within a rigid frame.

[14]On the occasion of its centennial in 1969, the Philadelphia Chapter of the American Institute of Architects memorialized Furness as its 'great architect of the past': For designing original and bold buildings free of the prevalent Victorian academicism and imitation, buildings of such vigor that the flood of classical traditionalism could not overwhelm them, or him, or his clients ... For shaping iron and concrete with a sensitive understanding of their particular characteristics that was unique for his time ... For his significance as innovator-architect along with his contemporaries John Root, Louis Sullivan and Frank Lloyd Wright ... For his masterworks, the Pennsylvania Academy of the Fine Arts, the Provident Trust Company, the Baltimore and Ohio Railroad Station, and the University of Pennsylvania Library (now renamed the Furness Building) ... For his outstanding abilities as draftsman, teacher and inventor ... For being a founder of the Philadelphia Chapter and of the John Stewardson Memorial Scholarship in Architecture ...

Mark-Lee Kirk's set designs for the 1942 Orson Welles film The Magnificent Ambersons seem to be based on Furness's ornate Neo-Grec interiors of the 1870s.

In 1973, the Philadelphia Museum of Art mounted the first retrospective of Furness's work, curated by James F. O'Gorman, George E. Thomas and Hyman Myers.

Thomas, Jeffrey A. Cohen and Michael J. Lewis authored Frank Furness: The Complete Works (1991, revised 1996), with an introduction by Robert Venturi.

[21] On September 14, a Pennsylvania state historical marker was dedicated in front of Furness's boyhood home at 1426 Pine Street, Philadelphia (now Peirce College Alumni Hall).