Following decades of neglect, during which many of Furness's most important buildings were demolished, there was a revival of interest in his work in the mid-20th century.
The critic Lewis Mumford, tracing the creative forces that had influenced Louis Sullivan and Frank Lloyd Wright, wrote in The Brown Decades (1931): "Frank Furness was the designer of a bold, unabashed, ugly, and yet somehow healthily pregnant architecture."

The architectural historian Henry-Russell Hitchcock, in his comprehensive survey Architecture: Nineteenth and Twentieth Centuries (revised 1963), saw beauty in that ugliness:
[O]f the highest quality, is the intensely personal work of Frank Furness (1839-1912) in Philadelphia.
His building for the Pennsylvania Academy of the Fine Arts in Broad Street was erected in 1872-76 in preparation for the Centennial Exposition.
The exterior has a largeness of scale and a vigor in the detailing that would be notable anywhere, and the galleries are top-lit with exceptional efficiency.
Still more original and impressive were his banks, even though they lay quite off the main line of development of commercial architecture in this period.
The most extraordinary of these, and Furness's masterpiece, was the Provident Institution in Walnut [sic Chestnut] Street, built as late as 1879.
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.

No small part of Furness's historical significance lies in the fact that the young Louis Sullivan picked this office - then known as Furness & Hewitt - to work in for a short period after he left Ware's School in Boston.
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.

Architect and critic Robert Venturi in Complexity and Contradiction in Architecture (1966) wrote, not unadmiringly, of the National Bank of the Republic (later the Philadelphia Clearing House):
The city street facade can provide a type of juxtaposed contradiction that is essentially two-dimensional.
Frank Furness' Clearing House, now demolished like many of his best works in Philadelphia, contained an array of violent pressures within a rigid frame.
The half-segmental arch, blocked by the submerged tower which, in turn, bisects the facade into a near duality, and the violent adjacencies of rectangles, squares, lunettes, and diagonals of contrasting sizes, compose a building seemingly held up by the buildings next door: it is an almost insane short story of a castle on a city street.

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 ...

And above all, for creating architecture of imagination, decisive self-reliance, courage, and often great beauty, an architecture which to our eyes and spirits still expresses the unusual personal character, spirit and courage for which he was awarded the Congressional Medal of H
Following decades of neglect, during which many of Furness's most important buildings were demolished, there was a revival of interest in his work in the mid-20th century. The critic Lewis Mumford, tracing the creative forces that had influenced Louis Sullivan and Frank Lloyd Wright, wrote in The Brown Decades (1931): "Frank Furness was the designer of a bold, unabashed, ugly, and yet somehow healthily pregnant architecture."
The architectural historian Henry-Russell Hitchcock, in his comprehensive survey Architecture: Nineteenth and Twentieth Centuries (revised 1963), saw beauty in that ugliness:
[O]f the highest quality, is the intensely personal work of Frank Furness (1839-1912) in Philadelphia. His building for the Pennsylvania Academy of the Fine Arts in Broad Street was erected in 1872-76 in preparation for the Centennial Exposition. The exterior has a largeness of scale and a vigor in the detailing that would be notable anywhere, and the galleries are top-lit with exceptional efficiency. Still more original and impressive were his banks, even though they lay quite off the main line of development of commercial architecture in this period. The most extraordinary of these, and Furness's masterpiece, was the Provident Institution in Walnut [sic Chestnut] Street, built as late as 1879. 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.
No small part of Furness's historical significance lies in the fact that the young Louis Sullivan picked this office - then known as Furness & Hewitt - to work in for a short period after he left Ware's School in Boston. 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.
Architect and critic Robert Venturi in Complexity and Contradiction in Architecture (1966) wrote, not unadmiringly, of the National Bank of the Republic (later the Philadelphia Clearing House):
The city street facade can provide a type of juxtaposed contradiction that is essentially two-dimensional. Frank Furness' Clearing House, now demolished like many of his best works in Philadelphia, contained an array of violent pressures within a rigid frame. The half-segmental arch, blocked by the submerged tower which, in turn, bisects the facade into a near duality, and the violent adjacencies of rectangles, squares, lunettes, and diagonals of contrasting sizes, compose a building seemingly held up by the buildings next door: it is an almost insane short story of a castle on a city street.
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 ...

And above all, for creating architecture of imagination, decisive self-reliance, courage, and often great beauty, an architecture which to our eyes and spirits still expresses the unusual personal character, spirit and courage for which he was awarded the Congressional Medal of H
Frank Heyling Furness