Exterior
The building is based on the U.S. Capitol building in Washington, D.C. The west facade ends in projecting bays, and a portico projects from the center of the building. At the base of the portico, seven granite archways brace and support the porch above. Eight fluted Corinthian columns line the portico. A cornice supports the pediment above depicting Minerva surrounded by Education, Justice, Industry and Mining. Above the flat roof with balustrade are two drums supporting a dome. The first drum consists of a colonnade of Corinthian columns; the second, Corinthian pilasters. Large arched windows line the drum walls. The dome is 64 m (210 ft) high, and supports a lantern with a smaller dome capped with a gold-leafed orbed finial.
Interior
The California Senate chamber seats its forty members in a large chamber room decorated in red, which is a reference to the British House of Lords (also the upper house of a bicameral legislature). The chamber is entered through a second-floor corridor. From the coffered ceiling hangs an electric reproduction of the original gas chandelier. A hand-carved dais caps off a recessed bay framed by Corinthian columns. The Latin phrase "Senatoris est civitatis libertatem tueri" ("It is the duty of the Senator to guard the civil liberties of the Commonwealth") lines the cornice. A portrait of George Washington by Jane Stuart, the daughter of Gilbert Stuart, is on the wall above. The State Seal hangs above. Statues of the Roman goddess of wisdom Minerva once overlooked both chambers. Today, Minerva, sculpted by Michael H. Casey, appears only in the senate chambers.