Article III — CALIFORNIA RESIDENTIAL CODE

The 2024 International Residential Code (IRC) as amended by the State of California Building Standards Commission and known as the 2025 California Residential Code (CRC), California Code of Regulations, Title 24, Part 2.5, with Appendices BF, BG, BH, and CJ is adopted by reference and amended as follows:

(2380, § 2, 12-2-25)

R309.2 One- and two-family dwellings automatic fire sprinkler systems is amended to read as follows:

R309.2 One- and two-family dwellings automatic sprinkler systems.

An automatic sprinkler system shall be installed in all new and existing one- and two-family dwellings when additions are made that increase the fire area to more than 3,600 square feet.

Exceptions:

Accessory Dwelling Unit, provided that all of the following are met:

1.1.

The unit meets the definition of an Accessory Dwelling Unit as defined in the Government Code Section 65852.2.

1.2.

The existing primary residence does not have automatic fire sprinklers.

1.3.

The accessory dwelling unit does not exceed 1,200 square feet in size.

1.4.

The unit is on the same lot as the primary residence.

1.5.

The unit meets all apparatus access and water supply requirements of Chapter 5 and Appendix B of the 2022 California Fire Code.

When additions are made to existing structures, causing the fire area to exceed 3,600 square feet, and all of the following are met:

2.1.

Building addition does not exceed 500 square feet.

2.2.

The resultant structure meets all water supply requirements of Chapter 5 and Appendix B of the 2022 California Fire Code.

(2380, § 2, 12-2-25)

Section 330.3.1 is amended to read as follows:

R330.3.1 Spacing. Individual ESS units shall be separated from each other by at least 3 feet (914 mm) except separation distances are documented to be adequate based on large-scale fire testing complying with Section 1207.1.7.

Section R330.4 is amended to read as follows:

R330.4 Location. ESS shall be installed only in the following locations:

Detached garages and detached accessory structures.

Attached garages separated from the dwelling unit living space in accordance with Section R302.6.

Outdoors or on the exterior side of exterior walls located not less than 3 feet (914 mm) from doors and windows directly entering the dwelling unit, and shall not be located below or above any emergency escape and rescue openings.

Enclosed utility closets, basements, and storage or utility spaces within dwelling units and sleeping units with finished or noncombustible walls and ceilings. Walls and ceilings of unfinished wood-framed construction shall be provided with not less than 5/8-inch (15.9 mm) Type X gypsum wallboard. Openings into the dwelling shall be equipped with solid wood doors not less than 1-3/8 inches (35 mm) in thickness, solid or honeycomb-core steel doors not less than 1-3/8 inches (35 mm) in thickness, or doors with a 20- minute fire protection rating. Doors shall be self-latching and equipped with a self-closing or an automatic- closing device. Penetrations through the required gypsum wallboard into the dwelling shall be protected as required by Section R302.11, Item 4. ESS shall not be installed in sleeping rooms, or in closets or spaces opening directly into sleeping rooms. (Material based on NFPA 855 2023 Ed.)

Section R330.7 is amended to read as follows:

R330.7 Fire detection. Rooms and areas within dwelling units, basements and attached garages in which ESS are installed shall be protected by smoke alarms in accordance with Section R314. A heat detector, listed and interconnected to the smoke alarms, shall be installed in locations within dwelling units and attached garages where smoke alarms cannot be installed based on their listing.

ESS installed in Group R-3 and townhomes shall comply with the following:

Rooms and areas within dwellings units, sleeping units, basements and attached garages in which ESS are installed shall be protected by smoke alarms in accordance with Section R314.

A listed heat alarm interconnected to the smoke alarms shall be installed in locations within dwelling units, sleeping units, and attached garages where smoke alarms cannot be installed based on their listing.

Exceptions:

A listed heat detector may be used in place of a heat alarm, so long as it is interconnected with devices that provide an audible alarm at all sleeping areas.

A fire sprinkler associated with an approved automatic sprinkler system that triggers an audible alarm upon activation of the waterflow switch, may be used in place of a heat alarm.

R902.1.2 is amended to read as follows:

R902.1.2 Roof coverings in all other areas. The entire roof covering of every existing structure where more than 50 percent of the total roof area is replaced within any one-year period, the entire roof covering of every new structure, and any roof covering applied in the alteration, repair or replacement of the roof of every existing structure, shall be fire-retardant roof covering that is at least Class A.

(2380, § 2, 12-2-25)

Table R602.10.3(3) Bracing Requirements Based On Seismic Design Category is amended to read as follows:

The title of Table R602.10.3(3) is amended to read:

TABLE R602.10.3(3) i, j

Footnotes "i" and "j" are added to Table R602.10.3(3), to read:

i.

Methods PBS, HPS, SFB and CS-SFB are not permitted in Seismic Design Categories D 0 , D 1 , and D 2 .

j.

Methods GB, DWB and PCP are not permitted in Seismic Design Categories D 0 , D 1 , and D 2 where S 1 is greater than or equal to 0.75.

(2380, § 2, 12-2-25)