[1][2] Hoffman entered Harvard College with the class of 1903, but received his degree (AB) in 1902 (he spent his senior year as an apprentice at Carrère and Hastings, an architectural firm in New York).
[3] In 1910, Hoffman established his own architectural firm in Manhattan, sharing office space with architect Harry Creighton Ingalls with whom he occasionally collaborated.
Attained through his Harvard College connections, Hoffman's largest and most notable residential commission was James Deering's Villa Vizcaya in Miami, Florida.
Deering, a wealthy industrialist, and his art director, Paul Chalfin, had spent three years in Europe amassing a large collection of architectural and decorative artifacts.
Inspired by the Villa Rezzonico in Bassano del Grappa, Italy, Deering and Chalfin decided that the palatial bayfront mansion would be an Italian Style.
In March of that year, The New York Times published an article that completely ignored Hoffman's contribution to the design of Villa Vizcaya (only attributing the plumbing to him) and credited Paul Chalfin.
After thirty-five years of ignoring Chalfin's claims to the architecture of Vizcaya, Hoffman met with an attorney and planned to sue over the gross misrepresentation of the article.
[10] Projects, other than Vizcaya, completed after 1907 and by 1919: Hoffman is sometimes included in the credits for the Henry Miller Theater, 124 West 43rd Street, New York City (completed 1918; demolished 2004-2009 except for the facade; Paul R. Allen and Harry Creighton Ingalls, associated architects) but according to Charles Over Cornelius, writing in 1918 in The Architectural Record, "at the inception of the project Mr. Allen associated himself with Mr. Ingalls and Mr. Hoffman, architects of the Little Theatre and Neighborhood Playhouse, for the designing and execution of this particular building.
At Mr. Hoffman's entrance into the government service at the very beginning of the work, the onus fell entirely upon Mr. Allen and Mr. Ingalls, and their competent cooperation has given to New York a theatre whose peer is scarce to be found.