Cal. Gov. Code § 24307
In any county having a population of 4,000,000 or more, the board of supervisors may designate any county officer as responsible for all or any of the functions of acquiring, constructing, leasing, managing and maintaining public buildings and facilities, which may be consolidated into a single department or other organizational unit.
Such responsible county officer shall not be required to have any special permit, registration, or license, provided that if such functions include the practice of any profession or trade for which a license, permit or registration is required, then the individual directly involved in such practice shall possess or act only under the supervision of someone who possesses the appropriate license, permit, or registration.
Where such responsibility is designated as described in this section, civil engineering work done for the county in the performance of such functions shall be accomplished under the authority of the responsible officer acting through a registered civil engineer. Responsibility for other civil engineering work shall remain with those officers currently designated.
Ca. Gov. Code § 24307