California Code, Health and Safety Code - HSC § 17922.2

(a) Notwithstanding any other provisions of this part, ordinances and programs adopted on or before January 1, 1993, that contain standards to strengthen potentially hazardous buildings pursuant to subdivision (b) of Section 8875.2 of the Government Code, shall incorporate the building standards in Appendix Chapter 1 of the Uniform Code for Building Conservation of the International Conference of Building Officials published in the California Building Standards Code, except for standards found by local ordinance to be inapplicable based on local conditions, as defined in subdivision (b), or based on an approved study pursuant to subdivision (c), or both. Ordinances and programs shall be updated in a timely manner to reflect changes in the model code, and more frequently if deemed necessary by local jurisdictions.

(b) For the purpose of subdivision (a), and notwithstanding the meaning of “local conditions” as used elsewhere in this part and in Part 2.5 (commencing with Section 18901), the term “local conditions” shall be limited to those conditions that affect the implementation of seismic strengthening standards on the following only:

(c) Any ordinance or program adopted on or before January 1, 1993, may include exceptions for local conditions not defined in subdivision (b) if the jurisdiction has approved a study on or before January 1, 1993, describing the effects of the exceptions. The study shall include socioeconomic impacts, a seismic hazards assessment, seismic retrofit cost comparisons, and earthquake damage estimates for a major earthquake, including the differences in costs, deaths, and injuries between full compliance with Appendix Chapter 1 of the Uniform Code for Building Conservation or the Uniform Building Code and the ordinance or program. No study shall be required pursuant to this subdivision if the exceptions for local conditions not defined in subdivision (b) result in standards or requirements that are more stringent than those in Appendix Chapter 1 of the Uniform Code for Building Conservation.

(d) Ordinances and programs adopted pursuant to this section shall conclusively be presumed to comply with the requirements of Chapter 173 of the Statutes of 1991.  1