A contract made under this article shall not be altered or changed in any manner, except when first ordered by a vote of two-thirds of the board, and with the consent of the contractor. The particular change or alteration shall be specified in writing and its cost agreed upon between the board and the contractor. In no case shall the board pay or become liable to pay for any extra work done or extra material furnished.
Source:
Section 20206.3, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=PCC§ionNum=20206.3..