300 Montgomery Street is the result of two distinct design campaigns which occurred in 1917 and 1941. The oldest portion of 300 Montgomery Street, originally a Bank of America, was designed by George Kelham. In 1941, the building was significantly expanded, doubling its size to fill the entire street wall of the Montgomery block between California and Pine streets.

ARG Conservation Services conducted a complete survey of the exterior façades of 300 Montgomery Street. The purpose of the survey was twofold: to provide accurate counts of conditions requiring repair and to remove any loose material posing a falling hazard.