California Code, Government Code - GOV § 70342

(a) If the county holds title to a shared use building and the court wishes to have additional space in the building, if the county agrees to allocate additional space, the county may charge the state reasonable rent for any space as may be agreed between the county and the Judicial Council.

(b) If the state holds title to a shared use building and the county wishes to have additional space in the building, if the state agrees to allocate additional space, the state may charge the county reasonable rent for any space as may be agreed to between the county and the Judicial Council.

(c) If the state and the county jointly hold title to a shared use building and either the court or the county wishes to have additional space in the building, the Judicial Council and the county may agree to modify the amount of space and the charges made for that space.

(d) If the state or the county is a lessee in a shared use building owned by a third party and the court or the county wishes to have additional space in the building, the Judicial Council or the county may negotiate with the lessor concerning the amount of space and the charges made for that space. This subdivision does not permit either the state or the county to occupy space in the building leased by the other party without the consent of that party.

(e) Unless the Judicial Council and the county agree otherwise, if either the Judicial Council or the county desires to decrease the amount of space it occupies in a shared use building, it may do so only after offering the other party the space on the same terms and conditions as to which it has proposed to transfer the space to a third party. Notwithstanding the transfer of space pursuant to this subdivision or the failure to use the space, the Judicial Council and the county are not relieved of their rights and responsibilities under the agreement entered into pursuant to Section 70343, unless that agreement is superseded by a subsequent agreement. As used in this subdivision, a “third party” means an entity other than the court or the county.