From 1904 through 1906 Thomas worked in the architectural office of John Galen Howard, who had prepared the master plan for the UCB campus.
In 1907 Thomas entered a partnership with architect George Plowman, and they designed some 50 residential buildings in the Arts and Crafts style.
[2] As Thomas took on bigger and more prominent projects, his work became more orthodox, though he continued to have an inclination for interior architecture.
[3] His work is characterized by unorthodox blending of various historic styles including Craftsman, Prairie School, Mission, Gothic, Tudor, Art Nouveau, English Cottage, and in his later years Viennese Secessionist.
[4] Thomas operated from 1910 to 1945 throughout California with his work influencing residential development styles in the Bay Area throughout the 20th century.