William Bourn, who was head of the Spring Valley Water Company, had made a fortune from his Empire Mine near Grass Valley. In 1897 he commissioned young Willis Polk to design this handsome town house in the Carolingian style, at 2550 Webster Street. It is a masterpiece of the bricklayers' and stonemasons' arts, with beautifully carved decorations and fine fixtures, such as the bronze lantern... Nothing like it was being built in the city in 1897. Polk also designed the offices and main residence at the Empire Mine, and contributed much of the design for Bourn's magnificent estate, Filoli, on the Peninsula

From San Francisco: Building the Dream City by James B. Alexander