17958.

 (a) Except as provided in subdivision (b), and in Sections 17958.8 and 17958.9, any city or county may make changes in the provisions adopted pursuant to Section 17922 and published in the California Building Standards Code or the other regulations thereafter adopted pursuant to Section 17922 to amend, add, or repeal ordinances or regulations which impose the same requirements as are contained in the provisions adopted pursuant to Section 17922 and published in the California Building Standards Code or the other regulations adopted pursuant to Section 17922 or make changes or modifications in those requirements upon express findings pursuant to Sections 17958.5 and 17958.7. If any city or county does not amend, add, or repeal ordinances or regulations to impose those requirements or make changes or modifications in those requirements upon express findings, the provisions published in the California Building Standards Code or the other regulations promulgated pursuant to Section 17922 shall be applicable to it and shall become effective 180 days after publication by the California Building Standards Commission. Amendments, additions, and deletions to the California Building Standards Code adopted by a city or county pursuant to Section 17958.7, together with all applicable portions of the California Building Standards Code, shall become effective 180 days after publication of the California Building Standards Code by the California Building Standards Commission.

(b) Commencing June 1, 2025, until June 1, 2031, inclusive, a city or county shall not make changes that are applicable to residential units in the provisions adopted pursuant to Section 17922 and published in the California Building Standards Code or the other regulations thereafter adopted pursuant to Section 17922 to amend, add, or repeal ordinances or regulations which impose the same requirements as are contained in the provisions adopted pursuant to Section 17922 and published in the California Building Standards Code or the other regulations adopted pursuant to Section 17922 or make changes or modifications in those requirements upon express findings pursuant to Sections 17958.5 and 17958.7, unless one of the following conditions is met:

(1) The changes or modifications are substantially equivalent to changes or modifications that were previously filed by the governing body of the city or county and were in effect as of January 1, 2025.

(2) The commission deems those changes or modifications necessary as emergency standards to protect health and safety.

(3) The changes or modifications relate to home hardening.

(4) The building standards relate to home hardening and are proposed for adoption by a fire protection district pursuant to Section 13869.7.

17958.5.

 (a) Except as provided in subdivision (c) and in Section 17922.6, in adopting the ordinances or regulations pursuant to Section 17958, a city or county may make those changes or modifications in the requirements contained in the provisions published in the California Building Standards Code and the other regulations adopted pursuant to Section 17922, including, but not limited to, green building standards, as it determines, pursuant to the provisions of Section 17958.7, are reasonably necessary because of local climatic, geological, or topographical conditions.

(b) For purposes of this section, a city or county may make reasonably necessary modifications to the requirements, adopted pursuant to Section 17922, including, but not limited to, green building standards, contained in the provisions of the code and regulations on the basis of local conditions.

(c) Commencing June 1, 2025, until June 1, 2031, inclusive, a city or county shall not make a change or modification as described in subdivision (a) or (b), including to green building standards, that is applicable to residential units, unless one of the following conditions is met:

(1) The changes or modifications are substantially equivalent to changes or modifications that were previously filed by the governing body of the city or county and were in effect as of January 1, 2025.

(2) The commission deems those changes or modifications necessary as emergency standards to protect health and safety.

(3) The changes or modifications relate to home hardening.

(4) The building standards relate to home hardening and are proposed for adoption by a local fire prevention district pursuant to Section 13869.7.

17958.7.

 (a) Except as provided in subdivision (c) and in Section 17922.6, the governing body of a city or county, before making any modifications or changes pursuant to Section 17958.5, shall make an express finding that such modifications or changes are reasonably necessary because of local climatic, geological, or topographical conditions. Such a finding shall be available as a public record. A copy of those findings, together with the modification or change expressly marked and identified to which each finding refers, shall be filed with the California Building Standards Commission. No modification or change shall become effective or operative for any purpose until the finding and the modification or change have been filed with the California Building Standards Commission.

(b) The California Building Standards Commission may reject a modification or change filed by the governing body of a city or county if no finding was submitted.

(c) Commencing June 1, 2025, until June 1, 2031, inclusive, the commission shall reject a modification or change to any building standard affecting a residential unit and filed by the governing body of a city or county, unless one of the following conditions is met:

(1) The changes or modifications are substantially equivalent to changes or modifications that were previously filed by the governing body of the city or county and were in effect as of January 1, 2025.

(2) The commission deems those changes or modifications necessary as emergency standards to protect health and safety.

(3) The changes or modifications relate to home hardening.

(4) The building standards relate to home hardening and are proposed for adoption by a local fire prevention district pursuant to Section 13869.7.

18929.1.

 (a) Except as provided in subdivision (c), the commission shall receive proposed building standards from state agencies for consideration in an 18-month code adoption cycle. The commission shall develop regulations setting forth the procedures for the 18-month adoption cycle. The regulations shall ensure all of the following:

(1) Adequate public participation in the development of building standards prior to submittal to the commission for adoption and approval.

(2) Adequate notice, in written form, to the public of the compiled building standards and their justification.

(3) Adequate technical review of proposed building standards and accompanying justification by advisory bodies appointed by the commission.

(4) Adequate time for review of recommendations by advisory bodies prior to action by the commission.

(5) The procedures shall meet the intent of the Administrative Procedure Act (Chapter 3.5 (commencing with Section 11340) of Part 1 of Division 3 of Title 2 of the Government Code) and Section 18930.

(b) Where this section is in conflict with other provisions of this part, the intent of this section shall prevail.

(c) Commencing June 1, 2025, until June 1, 2031, inclusive, subdivision (a) shall not apply to any building standards affecting residential units and proposed building standards affecting residential units shall not be considered, approved, or adopted by the commission, unless either any of the following conditions is met:

(1) The commission deems those changes necessary as emergency standards to protect health and safety.

(2) The building standards relate to home hardening and are proposed for adoption by the Office of the State Fire Marshal.

18930.

 (a) Except as provided in subdivision (g), any building standard adopted or proposed by state agencies shall be submitted to, and approved or adopted by, the California Building Standards Commission prior to codification. Prior to submission to the commission, building standards shall be adopted in compliance with the procedures specified in Article 5 (commencing with Section 11346) of Chapter 3.5 of Part 1 of Division 3 of Title 2 of the Government Code. Building standards adopted by state agencies and submitted to the commission for approval shall be accompanied by an analysis written by the adopting agency or state agency that proposes the building standards which shall, to the satisfaction of the commission, justify the approval thereof in terms of the following criteria:

(1) The proposed building standards do not conflict with, overlap, or duplicate other building standards.

(2) The proposed building standard is within the parameters established by enabling legislation and is not expressly within the exclusive jurisdiction of another agency.

(3) The public interest requires the adoption of the building standards. The public interest includes, but is not limited to, health and safety, resource efficiency, fire safety, seismic safety, building and building system performance, and consistency with environmental, public health, and accessibility statutes and regulations.

(4) The proposed building standard is not unreasonable, arbitrary, unfair, or capricious, in whole or in part.

(5) The cost to the public is reasonable, based on the overall benefit to be derived from the building standards.

(6) The proposed building standard is not unnecessarily ambiguous or vague, in whole or in part.

(7) The applicable national specifications, published standards, and model codes have been incorporated therein as provided in this part, where appropriate.

(A) If a national specification, published standard, or model code does not adequately address the goals of the state agency, a statement defining the inadequacy shall accompany the proposed building standard when submitted to the commission.

(B) If there is no national specification, published standard, or model code that is relevant to the proposed building standard, the state agency shall prepare a statement informing the commission and submit that statement with the proposed building standard.

(8) The format of the proposed building standards is consistent with that adopted by the commission.

(9) The proposed building standard, if it promotes fire and panic safety, as determined by the State Fire Marshal, has the written approval of the State Fire Marshal.

(b) In reviewing building standards submitted for its approval, the commission shall consider only the record of the proceedings of the adopting agency, except as provided in subdivision (b) of Section 11359 of the Government Code.

(c) Where the commission is the adopting agency, it shall consider the record submitted to, and considered by, the state agency that proposes the building standards and the record of public comment that results from the commission’s adoption of proposed regulations.

(d) (1) The commission shall give great weight to the determinations and analysis of the adopting agency or state agency that proposes the building standards on each of the criteria for approval set forth in subdivision (a). Any factual determinations of the adopting agency or state agency that proposes the building standards shall be considered conclusive by the commission unless the commission specifically finds, and sets forth its reasoning in writing, that the factual determination is arbitrary and capricious or substantially unsupported by the evidence considered by the adopting agency or state agency that proposes the building standards.

(2) Whenever the commission makes a finding, as described in this subdivision, it shall return the standard to the adopting agency or state agency that proposes the building standards for a reexamination of its original determination of the disputed fact.

(e) Whenever a building standard is principally intended to protect the public health and safety, its adoption shall not be a “factual determination” for purposes of subdivision (d). Whenever a building standard is principally intended to conserve energy or other natural resources, the commission shall consider or review the cost to the public or benefit to be derived as a “factual determination” pursuant to subdivision (d). Whenever a building standard promotes fire and panic safety, each agency shall, unless adopted by the State Fire Marshal, submit the building standard to the State Fire Marshal for prior approval.

(f) Whenever the commission finds, pursuant to paragraph (2) of subdivision (a), that a building standard is adopted by an adopting agency pursuant to statutes requiring adoption of the building standard, the commission shall not consider or review whether the adoption is in the public interest pursuant to paragraph (3) of subdivision (a).

(g) Commencing June 1, 2025, until June 1, 2031, inclusive, proposed building standards affecting residential units shall not be considered, approved, or adopted by the commission or any other adopting agency, unless either any of the following conditions is met:

(1) The commission deems those changes necessary as emergency standards to protect health and safety.

(2) The building standards relate to home hardening and are proposed for adoption by the Office of the State Fire Marshal.