Valuation Factor Studies

Under Government Code section 15606, the State Board of Equalization (Board) is charged with the duty of preparing and issuing instructions to California County Assessors designed to promote uniformity throughout the state in the assessment of property for purposes of taxation. Additionally, pursuant to Revenue and Taxation Code section 401.5, the Board is required to issue data to county assessors relating to costs of property and other information as, in the judgment of the Board, will promote uniformity in appraisal practices and assessed values within California. In an effort to comply with section 401.5, the Board annually publishes Assessors' Handbook Section 581, Equipment and Fixtures Index, Percent Good and Valuation Factors (AH 581).

Petition Procedures

The factors contained in AH 581 are updated for each January 1 lien date when current market data becomes available that indicate that the factor(s) should be adjusted. Interested parties may provide data to Board staff via a petition in support of changing factors contained in AH 581.

Current Studies

  • No current studies at this time

Completed Studies

In 2005, industry representatives expressed an interest for the Board to review current data to validate or update the information contained in AH 581 relative to the valuation of biopharmaceutical equipment and fixtures, non-production computer equipment, and semiconductor manufacturing equipment. Those studies were completed by a team comprised of Board staff, representatives from the various industries, and representatives of the California Assessors' Association.