Cal. Gov. Code § 25549.1
Any county or city and county may enter into leases and agreements relating to real property and buildings to be used jointly by the county or city and county and any private person, firm, or corporation pursuant to this article. As used in this article, "building" includes onsite and offsite facilities, utilities, and improvements, including permanent improvement of the grounds of a building, which, as agreed upon by the parties, are appropriate for the proper operation or function of the building to be occupied jointly by the county or city and county and the private person, firm, or corporation.
Any building, or portion thereof, which is used by a private person, firm, or corporation pursuant to this article shall be subject to the zoning and building code requirements of the local jurisdiction in which the building is situated.
Ca. Gov. Code § 25549.1