Cal. Gov. Code § 9108

The first floor of the State Capitol Building Annex is excepted from the provisions of this article. Such excepted space shall continue under the control of the Department of General Services. All other space in the State Capitol Building Annex shall be allocated from time to time by the Joint Rules Committee in accordance with its determination of the needs of the Legislature and the two houses thereof. The committee shall allocate such space as it determines to be necessary for facilities and agencies dealing with the Legislature as a whole including, but not limited to, press quarters, billrooms, telephone rooms, and offices for the Legislative Counsel and for committees created by the two houses jointly. The committee shall allocate to the Senate and Assembly, respectively, the space it determines to be needed by those houses and their committees and the officers, employees, and attachés thereof. The space thus allocated to the Senate and to the Assembly shall be allotted from time to time by the Senate Rules Committee and the Assembly Rules Committee, respectively.