Built in 1896 during the Union Iron Works period to serve as an office and administration building, Building 104 is the second oldest surviving structure in the Pier 70 complex. George Percey (1847-1900) was the architect. In its day, this building was touted as a “modern, fire-proof” structure. Few early examples of this use and construction survive in San Francisco. The finely-detailed Renaissance portico features banded rustication, engaged Ionic columns and a projecting cornice over an arched opening.

Building 104 survived the 1906 earthquake. Seismic safety concerns however, finally required that the building cease operation as a worksite in early 2004. The building will be closed and “mothballed,” awaiting the time when it can be retrofitted and given a new use.