Cal. Public Utilities Code § 306

(a) The office of the commission shall be in the City and County of San Francisco. The office shall always be open, legal holidays and nonjudicial days excepted. The commission shall hold its sessions at least once in each calendar month. The commission may also meet at such other times and in such places as may be expedient and necessary for the proper performance of its duties, and for that purpose may rent quarters or offices. (b) The meetings of the commission shall be open and public in accordance with the provisions of Article 9 (commencing with Section 11120) of Chapter 1 of Part 1 of Division 3 of Title 2 of the Government Code. In addition to the requirements of Section 11125 of the Government Code, the commission shall include in its notice of meetings the agenda of business to be transacted, and no item of business shall be added to the agenda subsequent to the notice in the absence of an unforeseen emergency situation. A rate increase shall not constitute an unforeseen emergency situation. As used in this subdivision, “meeting” shall include all investigations, proceedings, and showings required by law to be open and public. (c) The commission shall have a seal, bearing the inscription “Public Utilities Commission State of California.” The seal shall be affixed to all writs and authentications of copies of records and to such other instruments as the commission shall direct. (d) The commission may procure all necessary books, maps, charts, stationery, instruments, office furniture, apparatus, and appliances.