Cal. Rev. & Tax. Code § 82

An application for reduction in the value of new construction that is in progress on the lien date on the current roll may be filed during the regular filing period for that year as set forth in Section 1603 or 1840. An application for reduction in the base year value determined upon completion of new construction may be filed during the regular equalization period for the year in which the assessment is placed on the assessment roll or in any of the three succeeding years, as provided in Section 80.