Section R302 — FIRE-RESISTANT CONSTRUCTION — 2025 California Residential Code (Title 24, Part 2.5)

R302.1 Exterior walls. ¶

R302.1 Exterior walls. Construction, projections, openings and penetrations of exterior walls of dwellings , townhouses and accessory buildings shall comply with Table R302.1(1) based on fire separation distance; or dwellings and accessory buildings equipped throughout with an automatic sprinkler system installed in accordance with Section R309 shall comply with Table R302.1(2) based on fire separation distance. For the purposes of determining fire separation distance, dwellings and townhouses on the same lot shall be assumed to have an imaginary line between them. Where a new dwelling or…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.2 Townhouses. ¶

R302.2 Townhouses. Walls separating townhouse units shall be constructed in accordance with Section R302.2.1 or R302.2.2 and shall comply with Sections R302.2.3 through R302.2.5. R302.2.1 Double walls. Each townhouse unit shall be separated from other townhouse units by two 1-hour fire-resistance-rated wall assemblies tested in accordance with ASTM E119, UL 263 or Section 703.2.2 of the California Building Code. 3-24 2025 CALIFORNIA RESIDENTIAL CODE on Jul 18, 2025 11:14 AM (CDT) THEREUNDER. BUILDING PLANNING R302.2.2 Common walls. Common walls separating townhouse units shall be assigned a…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.3 Two-family dwellings. ¶

R302.3 Two-family dwellings. Dwelling units in two-family dwellings shall be separated from each other in accordance with Sections 302.3.1 through 302.3.5, regardless of whether a lot line exists between two dwelling units. R302.3.1 Dwelling unit separation. The two dwelling units shall be separated by fire-resistance rated assemblies that are vertical, horizontal, or a combination thereof. R302.3.2 Fire-resistance rating. Vertical and horizontal assemblies separating dwelling units shall have a fire-resistance rating of 1 hour, or a fire-resistance rating of one-half hour in buildings…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.4 Dwelling unit rated penetrations. ¶

R302.4 Dwelling unit rated penetrations. Penetrations of wall or floor-ceiling assemblies required to be fire-resistance rated in accordance with Section R302.2 or R302.3 shall be protected in accordance with this section. R302.4.1 Through penetrations. Through penetrations of fire-resistance-rated wall or floor assemblies shall comply with Section R302.4.1.1 or R302.4.1.2. Exceptions: 1. Where the penetrating items are steel, ferrous or copper pipes, tubes or conduits, the annular space shall be protected as follows: 1.1. In concrete or masonry wall or floor assemblies, concrete, grout or…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.5 Dwelling unit garage opening and penetration protection. ¶

R302.5 Dwelling unit garage opening and penetration protection. Openings and penetrations through the walls or ceilings separating the dwelling unit from the garage shall be in accordance with Sections R302.5.1 through R302.5.3. R302.5.1 Opening protection. Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and dwelling unit 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) thick, or…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.6 Dwelling unit garage and/or carport fire separation. ¶

R302.6 Dwelling unit garage and/or carport fire separation. The garage and/or carport shall be separated as required by Table R302.6. Openings in garage walls shall comply with Section R302.5. Attachment of gypsum board shall comply with Table R702.3.5. The wall separation provisions of Table R302.6 shall not apply to garage walls that are perpendicular to the adjacent dwelling unit wall. A separation is not required between the dwelling unit and a carport, provided the carport is entirely open on two or more sides and there are not enclosed areas above. on Jul 18, 2025 11:14 AM (CDT)…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.7 Under-stair protection. ¶

R302.7 Under-stair protection. Enclosed space under stairs that is accessed by a door or access panel shall have walls, under-stair surface and any soffits protected on the enclosed side with [1] / 2 -inch (12.7 mm) gypsum board.

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R302.8 Foam plastics. For requirements for foam plastics, see Section R303. ¶

R302.8 Foam plastics. For requirements for foam plastics, see Section R303. R302.8.1 Interior finish. Foam plastics used as interior finishes shall comply with Section R303.5.10.

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R302.9 Flame spread index and smoke-developed index for wall and ceiling finishes. ¶

R302.9 Flame spread index and smoke-developed index for wall and ceiling finishes. Flame spread and smoke-developed indices for wall and ceiling finishes shall be in accordance with Sections R302.9.1 through R302.9.4. R302.9.1 Flame spread index. Wall and ceiling finishes shall have a flame spread index of not greater than 200. Exception: Flame spread index requirements for finishes shall not apply to trim defined as picture molds, chair rails, baseboards and handrails; to doors and windows or their frames; or to materials that are less than [1] / 28 inch (0.91 mm) in thickness cemented to…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.10 Flame spread index and smoke-developed index for insulation. ¶

R302.10 Flame spread index and smoke-developed index for insulation. Flame spread and smoke-developed index for insulation shall be in accordance with Sections R302.10.1 through R302.10.4. R302.10.1 Insulation. Insulating materials installed within floor-ceiling assemblies, roof-ceiling assemblies, wall assemblies, crawl spaces and attics shall comply with the requirements of this section. They shall exhibit a flame spread index not to exceed 25 and a smoke-developed index not to exceed 450 where tested in accordance with ASTM E84 or UL 723. Insulating materials, where tested in accordance…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.11 Fireblocking. ¶

R302.11 Fireblocking. In combustible construction, fireblocking shall be provided to cut off both vertical and horizontal concealed draft openings and to form an effective fire barrier between stories, and between a top story and the roof space. Fireblocking shall be provided in wood-framed construction in the following locations: 1. In concealed spaces of stud walls and partitions, including furred spaces and parallel rows of studs or staggered studs, as follows: 1.1. Vertically at the ceiling and floor levels. 1.2. Horizontally at intervals not exceeding 10 feet (3048 mm). 2. At…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.12 Draftstopping. ¶

R302.12 Draftstopping. In combustible construction where there is usable space both above and below the concealed space of a floor-ceiling assembly, draftstops shall be installed so that the area of the concealed space does not exceed 1,000 square feet (92.9 m [2] ). Draftstopping shall divide the concealed space into approximately equal areas. Where the assembly is enclosed by a floor membrane above and a ceiling membrane below, draftstopping shall be provided in floor-ceiling assemblies under the following circumstances: 1. Ceiling is suspended under the floor framing. 2. Floor framing is…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.13 Fire protection of floors. ¶

R302.13 Fire protection of floors. Floor assemblies that are not required elsewhere in this code to be fire-resistance rated, shall be provided with a [1] / 2 -inch (12.7 mm) gypsum wallboard membrane, [5] / 8 -inch (16 mm) wood structural panel membrane, or equivalent on the underside of the floor framing member. Penetrations or openings for ducts, vents, electrical outlets, lighting, devices, luminaires, wires, speakers, drainage, piping and similar openings or penetrations shall be permitted. Exceptions: 1. Floor assemblies located directly over a space protected by an automatic sprinkler…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.14 Combustible insulation clearance. ¶

R302.14 Combustible insulation clearance. Combustible insulation shall be separated not less than 3 inches (76 mm) from recessed luminaires, fan motors and other heat-producing devices. Exception: Where heat-producing devices are listed for lesser clearances, combustible insulation complying with the listing requirements shall be separated in accordance with the conditions stipulated in the listing. Recessed luminaires installed in the building thermal envelope shall meet the requirements of the California Energy Code .

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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R302.15 Fire-retardant-treated wood. ¶

R302.15 Fire-retardant-treated wood. Fire-retardant-treated wood (FRTW) is any wood product that, when impregnated with chemicals by a pressure process or other means during manufacture, shall have, when tested in accordance with ASTM E84 or UL 723, a listed flame spread index of 25 or less. In addition, the ASTM E84 or UL 723 test shall be continued for an additional 20-minute period and the flame front shall not progress more than 10.5 feet (3200 mm) beyond the center line of the burners at any time during the test. R302.15.1 Pressure process. For wood products impregnated with chemicals by…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

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