I am greatly pleased to announce that my lengthy paper on Frank Gilbreth's construction companies, history and works has finally reached print in the UK-based Construction History Journal. As with all such things, it took a while—almost two full years—to get through the acceptance, editing and publication cycle, but there it is!
I regret that I can't simply post a full offprint of the article, but a summary of its core information, the list of over ninety construction works by the three companies of Frank B. Gilbreth, can be found here in the Essays section.
The takeaway here for most readers is that Frank Gilbreth was not briefly in the construction trade (as the vast number of academic writings imply) nor was his success just boasting (as the family lore books imply) but one of America's most successful, innovative and prolific commercial builders at the turn of the 20th Century. From the founding of his own company in 1895 to his turn to the more famous career of efficiency engineering and management consulting about 1912, “Frank B. Gilbreth, General Contractor” built some ninety projects across the U.S., most of large to very large scale.

I started off researching this side topic with the idea that construction was indeed a brief and largely inconsequential passage in Frank's life, and that his projects, if any, were long since demolished. Two years of research later, I found the truth to be almost the complete opposite. The appearance of this paper is sure to shake up the management history field simply by awakening it to the sturdy presence of Frank Gilbreth's first career and its impact on all that followed. (The inquiries have already started despite the journal not yet having been filed with JSTOR and other acacdemic repositories.)
If the essay—just a list, really—doesn't answer enough of your questions about Frank's construction era and the works he built, many of which stand and are in use today, please do ask in a comment or drop me a note. I'm happy to chat about the topic!