As his uncle's associate, Louis contributed to the design of several notable buildings including La Jolla Woman's Club (now listed on the National Register of Historic Places) and the Ellen Browning Scripps residence at 700 Prospect Street (now the Museum of Contemporary Art San Diego).
[1][3] In 1933, within hours of the 1933 Long Beach earthquake, Gill traveled to the scene in his role as president of the California State Board of Architectural Examiners.
[2] Gill was a co-founder of the San Diego Chapter of the American Institute of Architects.
He served on the California State Board of Architectural Examiners for more than 20 years, including two terms as president (1932–1934 and 1947–1949).
He and his wife lived in San Diego's Mission Hills neighborhood until July 1969, when he moved to Studio City.