CEBC · California Existing Building Code
Accessibility, alarms, carbon monoxide and exterior wall coverings
This hub orients readers to CEBC rules on accessibility, smoke and carbon monoxide alarms, and exterior wall covering work and points to the controlling sections and cross‑references.
Last reviewed: July 6, 2026
Overview
This part of the California Existing Building Code (CEBC) brings together life‑safety and durability requirements that apply to many alteration, addition and change‑of‑occupancy projects: accessibility for existing buildings, smoke alarms, carbon monoxide detection, and rules for adding or replacing exterior wall coverings and envelopes. These topics are handled in the CEBC provisions of Chapter 3 (see the Chapter 3 table of contents) and specifically in CEBC Sections §306 through §309.
Why it matters: accessibility upgrades link to California Building Code Chapter 11B (and Chapter 11A for HCD‑jurisdiction multifamily housing), carbon monoxide and smoke alarm triggers and installation requirements cross‑reference the California Fire Code and the Residential Code, and exterior wall covering work can require compliance with new‑construction rules (CBC Chapters 14 and 26) when the scope is large. These cross‑references and statutory triggers (for example Health & Safety Code requirements for CO alarms) mean you must read §306–§309 alongside the CBC, CFC and CRC provisions they reference.
In this section
- What accessibility upgrades are required for alterations to existing buildings?
- What are the smoke alarm and carbon monoxide detection requirements for alterations?
- What Chapter 3A differences apply to OSHPD (health‑care) buildings?
- When do additions or replacements of exterior wall coverings trigger code upgrades?
Code references
Grounded in the retrieved California Existing Building Code — click a citation to read the verbatim passage:
CEBC § 307.1 High relevance — show source text
[HCD 1-AC] Accessibility requirements for covered multifamily dwellings, as defined in Chapter 2 of the California Building Code, are promulgated under HCD authority and are located in Chapter 11A of the California Building Code.
SECTION 307—SMOKE ALARMS
307.1 Smoke alarms. Where an alteration, addition, change of occupancy or relocation of a building is made to an existing building or structure of a Group R and I-1 occupancy, the existing building shall be provided with smoke alarms in accordance with the California Fire Code or Section R310 of the California Residential Code .
Exception: Work classified as Level 1 Alterations in accordance with Chapter 7.
SECTION 308—CARBON MONOXIDE DETECTION
308.1 Carbon monoxide detection. Where an addition, alteration, change of occupancy or relocation of a building is made to an existing building, the existing building shall be provided with carbon monoxide detection in accordance with the California Fire Code or Section R311 of the California Residential Code .
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PROVISIONS FOR ALL COMPLIANCE METHODS
308.2 Carbon monoxide alarms in existing portions of a building. [HCD 1 & HCD 2] Pursuant to Health and Safety Code Section 17926, carbon monoxide detection shall be provided in all existing Group R buildings, as required in Section 915 of the California Building Code or Section R315 of the California Residential Code, as applicable.
308.2.1 Carbon monoxide detection in existing Group E occupancy buildings. Where the new addition includes any of the conditions identified in the California Fire Code Sections 915.1.2 through 915.1.6, carbon monoxide detection shall be installed in accordance with Section 915 of the California Fire Code. No person shall install, market, distribute, offer for sale, or sell any carbon monoxide device in the State of California unless the device and instructions have been approved and listed by the Office of the State Fire Marshal.
SECTION 309—ADDITIONS AND REPLACEMENTS OF EXTERIOR WALL COVERINGS AND EXTERIOR WALL ENVELOPES
309.1 General. The provisions of Section 309 apply to all alterations, repairs, additions, relocations of structures and changes of occupancy regardless of compliance method.
309.2 Additions and replacements. Where an exterior wall covering or exterior wall envelope is added or replaced, the materials and methods used shall comply with the requirements for new construction in Chapter 14 and Chapter 26 of the California Building Code if the added or replaced exterior wall covering or exterior wall envelope involves two or more contiguous stories and comprises more than 15 percent of the total wall area on any side of the building.
309.2.1 Automatic sprinkler systems. Combustible exterior wall covering or combustible exterior wall envelopes shall not be added to an existing high-rise building that is not protected throughout with an automatic sprinkler system.
Exceptions:
- Where such material is located on a single story and is less than 15 percent of the wall area on any side of the building.
- Water-resistive barriers installed in accordance with Section 1402.6 of the California Building Code .
CEBC § 1.10.1 High relevance — show source text
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Chapter 3 Provisions for All Compliance Methods.
Chapter 3 guides the use of the three compliance methods of the CEBC and provides requirements that apply globally. The globally applicable requirement include general requirements related to buildings materials and other applicable codes, storm shelters, structural loads, in-situ load tests, accessibility, smoke alarms, carbon monoxide detection and exterior wall coverings.
Chapter 3A Provisions for All Compliance Methods.
Chapter 3A controls the compliance options for alteration, repair, addition, evaluation and change of occupancy of existing structures regulated by the Department of Health Care Access and Information/Office of Statewide Hospital Planning and Development, which include hospitals and correctional treatment centers (applications listed in Sections 1.10.1 (OSHPD 1).
Chapter 4 Repairs.
Chapter 4, a chapter independent of the three compliance methods, governs the repair of existing buildings. The provisions define conditions under which repairs may be made using materials and methods like those of the original construction or the extent to which repairs must comply with requirements for new buildings.
Chapter 4A Repairs.
Chapter 4A governs the repair of existing buildings regulated by the Department of Health Care Access and Information/Office of State- wide Hospital Planning and Development, which include hospitals and correctional treatment centers (applications listed in Sections 1.10.1 (OSHPD 1).
Chapter 5 Prescriptive Compliance Method.
Chapter 5 provides one of the three main options of compliance available in the CEBC for buildings and structures undergoing alteration, addition or change of occupancy. The base requirements are more administrative in nature. The structural triggers for upgrades are consistent with the Work Area Method.
Chapter 5A Prescriptive Compliance Method.
Chapter 5A provides details for the prescriptive compliance method for alteration, addition and change of occupancy of existing build- ings and structures regulated by the Department of Health Care Access and Information/Office of Statewide Hospital Planning and Development, which include hospitals and correctional treatment centers (applications listed in Sections 1.10.1 (OSHPD 1).
Chapter 6 Classification of Work.
Chapter 6 provides an overview of the Work Area Method and defines the different classifications of work including alterations, change of occupancy, additions and historic buildings. Detailed requirements for all of these are given in subsequent Chapters 7 through 11.
Chapter 7 Alterations—Level 1.
Chapter 7 provides the technical requirements for those existing buildings that undergo Level 1 alterations as described in Section 602, which includes replacement or covering of existing materials, elements, equipment or fixtures using new materials for the same purpose. This chapter is distinguished from Chapters 8 and 9 by only involving replacement of building components with new components with no reconfiguration of space.
Chapter 8 Alterations—Level 2.
A Level 2 alteration is an alteration involving space reconfiguration that could be up to and including 50 percent of the area of the building or addition of a new building system. Level 2 alterations also include the extension or addition of any system or equipment. The purpose of Chapter 8 is to provide detailed requirements and provisions to identify the required improvements in the existing building elements, means of egress, fire protection, structural systems, energy efficiency, and other building systems include electrical, mechanical and plumbing when a building is being altered.
Chapter 9 Alterations—Level 3.
CEBC § 3-4 High relevance — show source text
303 Storm Shelters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
304 Structural Design Loads and Evaluation and Design Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
305 In-Situ Load Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
306 Accessibility for Existing Buildings . . . . . . . . . . . . . . . 3-6
307 Smoke Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
308 Carbon Monoxide Detection . . . . . . . . . . . . . . . . . . . . . 3-6
309 Additions and Replacements of Exterior Wall Coverings and Exterior Wall Envelopes . . . . . . . . . 3-7
310 [OSHPD 1R, 2 and 5] Services/Systems and Utilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
311 [OSHPD 1R, 2 and 5] Means of Egress . . . . . . . . . . . . . . . 3-7
312 [OSHPD 1R] Hospital SPC and Freestanding Buildings Removed from General Acute Care Service Remaining under the Jurisdiction of OSHPD . . . . . . . . . . . . . . . . . 3-7
313 [SFM] Existing Group R-1 and Group R-2 Occupancies . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
314 [SFM] Existing High-Rise Buildings . . . . . . . . . . . . . . . .3-11
315 [SFM] Existing Group I Occupancies . . . . . . . . . . . . . . .3-13
316 [SFM] Existing Group L Occupancies. . . . . . . . . . . . . . .3-14
317 [BSC, DSA-SS & DSA-SS/CC] Earthquake Evaluation and Design for Retrofit of Existing Buildings. . . . . . . . . .3-16
318 [BSC, DSA-SS & DSA-SS/CC] Definitions . . . . . . . . . . . .3-18
319 [BSC, DSA-SS & DSA-SS/CC] Seismic Criteria Selection for Existing Buildings . . . . . . . . . . . . . . . . . . . . . . . . . .3-18
320 [BSC, DSA-SS & DSA-SS/CC] Method A. . . . . . . . . . . . . .3-21
CEBC § 915.4.2 High relevance — show source text
Exceptions:
1. Where installed in buildings without commercial power, battery-powered carbon monoxide alarms shall be an acceptable alternative. 2. Carbon monoxide alarms in Group R occupancies shall be permitted to receive their primary power from other power sources recognized for use by NFPA 720. 3. Carbon monoxide alarms in Group R occupancies shall be permitted to be battery-powered or plug-in with a battery backup in existing buildings built prior to January 1, 2011, under any of the following conditions: 3.1. No construction is taking place. 3.2. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 3.3. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck. 3.4. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.
915.4.2 Listings. Residential carbon monoxide alarms shall be listed in accordance with UL 2034.
No person shall install, market, distribute, offer for sale or sell any carbon monoxide device in the State of California unless the device and instructions have been approved and listed by the Office of the State Fire Marshal.
915.4.3 Combination alarms. Combination carbon monoxide/smoke alarms shall be an acceptable alternative to carbon monoxide alarms. Combination carbon monoxide/smoke alarms shall be listed in accordance with UL 217 and UL 2034. Combination carbon monoxide/smoke alarms shall comply with Section 915, and all requirements for listing and approval by the Office of the State Fire Marshal for smoke alarms.
915.4.4 Interconnection. Where more than one carbon monoxide alarm is required to be installed within a dwelling unit or within a sleeping unit in Group R occupancies, the alarms shall be interconnected in a manner that activation of one alarm shall activate all of the alarms in the individual unit.
Exception : Interconnection is not required in existing buildings, built prior to January 1, 2011, under any of the following conditions: 1. Physical interconnection is not required where listed wireless alarms are installed and all alarms sound upon activation of one alarm.
2. No construction is taking place. 3. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 4. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding or the addition or replacement of windows or doors, or the addition of a porch or deck. 5. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.
915.5 Carbon monoxide detection systems. Carbon monoxide detection systems shall be an acceptable alternative to carbon monoxide alarms and shall comply with Sections 915.5.1 through 915.5.3.
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CEBC § 915.5 High relevance — show source text
2. No construction is taking place. 3. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 4. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck. 5. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.
[F] 915.5 Carbon monoxide detection systems. Carbon monoxide detection systems shall be an acceptable alternative to carbon monoxide alarms and shall comply with Sections 915.5.1 through 915.5.3.
[F] 915.5.1 General. Carbon monoxide detectors shall be listed in accordance with UL 2075.
[F] 915.5.2 Locations. Carbon monoxide detectors shall be installed in the locations specified in Section 915.2 or NFPA 72.
[F] 915.5.3 Combination detectors. Combination carbon monoxide/smoke detectors shall be an acceptable alternative to carbon monoxide detectors, provided that they are listed in accordance with UL 268 and UL 2075.
Combination carbon monoxide/smoke detectors shall comply with all requirements for listing and approval by the Office of the State Fire Marshal for smoke alarms.
[F] 915.5.4 Occupant notification. Activation of a carbon monoxide detector shall annunciate at the control unit and shall initiate audible and visible alarm notification throughout the building.
Exception: Occupant notification is permitted to be limited to the area where the carbon monoxide alarm signal originated and other signaling zones in accordance with the fire safety plan, provided that the alarm signal from an activated carbon monoxide detector is automatically transmitted to an approved on-site location or off-premises location.
[F] 915.5.5 Duct detection. Carbon monoxide detectors placed in environmental air ducts or plenums shall not be used as a substitute for the required protection in Section 915.
[F] 915.6 Maintenance. Carbon monoxide alarms and carbon monoxide detection systems shall be maintained in accordance with NFPA 72. Carbon monoxide alarms and carbon monoxide detectors that become inoperable or begin producing end-of-life signals shall be replaced.
915.6.1 Enclosed parking garages. Carbon monoxide and nitrogen dioxide detectors installed in enclosed parking garages in accor- dance with Section 403.7.2 of the California Mechanical Code shall be maintained in accordance with the manufacturer’s instructions and their listing. Detectors that become inoperable or begin producing end-of-life signals shall be replaced.
915.7 Visible alarms. In buildings containing covered multifamily dwellings as defined in Chapter 2, all required carbon monoxide alarms shall be equipped with the capability to support visible alarm notification in accordance with NFPA 72.
SECTION 916—GAS DETECTION SYSTEMS
[F] 916.1 Gas detection systems. Gas detection systems required by this code shall comply with Sections 916.2 through 916.11.
[F] 916.2 Permits. Permits shall be required as set forth in Section 105.6.10 of the California Fire Code .
CEBC § 1.10.1 High relevance — show source text
CHAPTER TOPICS Col2 CHAPTER SUBJECTS 1, 2 Administrative Requirements and Definitions 3 Provisions for all Compliance Methods 4 Repairs 5 Prescriptive Compliance Method for Existing Buildings 6–11 Work Area Compliance Method for Existing Buildings 13 Performance Compliance Method for Existing Buildings 14 Relocated Buildings 15 Construction Safeguards 16 Referenced Standards Appendix A Guidelines for Seismic Retrofit of Existing Buildings Appendix B Supplementary Accessibility Requirements for Existing Buildings Appendix C Guidelines for Wind Retrofit of Existing Buildings Appendix D Board of Appeals Appendix E Temporary Emergency Uses Resource A Guidelines on Fire Ratings of Archaic Materials and Assemblies CALIFORNIA BUILDING CODE CORRELATED TOPICS
The CEBC requirements for construction safeguards are directly correlated to the requirements of the CBC. The following table shows chapters of the CBC that are correlated with the CEBC:
CEBC/CBC CORRELATED TOPICS Col2 Col3 CEBC CHAPTER/SECTION CBC CHAPTER/SECTION SUBJECT Chapter 15 Chapter 33 Construction safeguards Chapter 1 Scope and Administration.
Chapter 1 establishes the limits of applicability of the code and describes how the code is to be applied and enforced. The provisions of Chapter 1 establish the authority and duties of the code official appointed by the authority having jurisdiction and also establish the rights and privileges of the design professional, contractor and property owner.
Chapter 2 Definitions.
Chapter 2 is the repository of the definitions of terms used in the body of the code. The user of the code should be familiar with and consult this chapter because the definitions are essential to the correct interpretation of the code and because the user may not be aware that a term is defined.
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Chapter 3 Provisions for All Compliance Methods.
Chapter 3 guides the use of the three compliance methods of the CEBC and provides requirements that apply globally. The globally applicable requirement include general requirements related to buildings materials and other applicable codes, storm shelters, structural loads, in-situ load tests, accessibility, smoke alarms, carbon monoxide detection and exterior wall coverings.
Chapter 3A Provisions for All Compliance Methods.
Chapter 3A controls the compliance options for alteration, repair, addition, evaluation and change of occupancy of existing structures regulated by the Department of Health Care Access and Information/Office of Statewide Hospital Planning and Development, which include hospitals and correctional treatment centers (applications listed in Sections 1.10.1 (OSHPD 1).
Chapter 4 Repairs.
Chapter 4, a chapter independent of the three compliance methods, governs the repair of existing buildings. The provisions define conditions under which repairs may be made using materials and methods like those of the original construction or the extent to which repairs must comply with requirements for new buildings.
Chapter 4A Repairs.
Chapter 4A governs the repair of existing buildings regulated by the Department of Health Care Access and Information/Office of State- wide Hospital Planning and Development, which include hospitals and correctional treatment centers (applications listed in Sections 1.10.1 (OSHPD 1).
CEBC § 1-31 High relevance — show source text
114 Stop Work Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31
115 Unsafe Structures and Equipment . . . . . . . . . . . . . . 1-31
116 Emergency Measures . . . . . . . . . . . . . . . . . . . . . . . . . . 1-32
117 Demolition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-32
CHAPTER 2 DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
201 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
202 General Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
CHAPTER 3 PROVISIONS FOR ALL COMPLIANCE
METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
301 Administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
302 General Provisions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
303 Storm Shelters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
304 Structural Design Loads and Evaluation and Design Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
305 In-Situ Load Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
306 Accessibility for Existing Buildings . . . . . . . . . . . . . . . 3-6
307 Smoke Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
308 Carbon Monoxide Detection . . . . . . . . . . . . . . . . . . . . . 3-6
309 Additions and Replacements of Exterior Wall Coverings and Exterior Wall Envelopes . . . . . . . . . 3-7
310 [OSHPD 1R, 2 and 5] Services/Systems and Utilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
311 [OSHPD 1R, 2 and 5] Means of Egress . . . . . . . . . . . . . . . 3-7
CEBC § 1.2 High relevance — show source text
No person shall install, market, distribute, offer for sale or sell any carbon monoxide device in the State of California unless the device and instructions have been approved and listed by the Office of the State Fire Marshal.
R311.1.2 Installation. Carbon monoxide alarms, and combination carbon monoxide and smoke alarms, shall be installed in accordance with their listing and the manufacturer’s instructions.
R311.2 Where required. Carbon monoxide alarms shall be provided in accordance with Sections R311.2.1 and R311.2.2.
Pursuant to Health and Safety Code Section 17926, carbon monoxide devices shall be installed in all existing dwelling units as required in this section.
R311.2.1 Existing buildings and new construction. For existing buildings and new construction, carbon monoxide alarms shall be provided in dwelling units where either or both of the following conditions exist.
- The dwelling unit contains a fuel-fired appliance or fireplace.
- The dwelling unit has an attached garage with an opening that communicates with the dwelling unit.
R311.2.2 Alterations, repairs and additions. Where an addition is made to an existing dwelling, or a fuel-burning heater, appli- ance or fireplace is added to an existing dwelling, not previously required to be provided with carbon monoxide alarms, new carbon monoxide alarms shall be installed in accordance with Section R311.
Exceptions:
- Work involving the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck.
- Installation, alteration or repairs of plumbing systems.
- Installation, alteration or repairs of mechanical systems that are not fuel fired.
R311.3 Location. Carbon monoxide alarms in dwelling units shall be installed and maintained in accordance with the manufacturer’s published instructions in the following locations: 1. Outside of each separate sleeping area in the immediate vicinity of the bedrooms. 2. On every occupiable level of a dwelling unit, including basements. 3. Where a fuel-burning appliance is located within a bedroom or its attached bathroom, a carbon monoxide alarm shall be installed within the bedroom.
R311.4 Combination alarms. Combination carbon monoxide and smoke alarms shall be permitted to be used in lieu of carbon monoxide alarms.
Combination carbon monoxide/smoke alarms shall comply with Section R311 and all requirements for listing and approval by the Office of the State Fire Marshal for smoke alarms.
R311.5 Interconnectivity. Where more than one carbon monoxide alarm is required to be installed within an individual dwelling unit in accordance with Section R311.3, the alarm devices shall be interconnected in such a manner that the actuation of one alarm will activate all of the alarms in the individual dwelling unit. Physical interconnection of carbon monoxide alarms shall not be required where listed wireless alarms are installed and all alarms sound upon activation of one alarm.
Exception: Interconnection of carbon monoxide alarms in existing buildings built prior to January 1, 2011, shall not be required under any of the following conditions: 1. Where alterations or repairs do not result in removal of interior wall or ceiling finishes exposing the structure, unless there is an attic, crawl space or basement available that could provide access for interconnection without the removal of interior finishes.
CEBC § 915.3.1 Medium relevance — show source text
915.3.1 Alarm limitations. Carbon monoxide alarms shall only be installed in dwelling units and in sleeping units. They shall not be installed in locations where the code requires carbon monoxide detectors to be used.
915.3.2 Fire alarm system required. New buildings that are required by Section 907.2 to have a fire alarm system and by Section 915.2 to have carbon monoxide detectors shall be connected to the fire alarm system in accordance with NFPA 72.
915.3.3 Fire alarm systems not required. In new buildings that are not required by Section 907.2 to have a fire alarm system, carbon monoxide detection shall be provided by one of the following:
- Carbon monoxide detectors connected to an approved carbon monoxide detection system in accordance with NFPA 72.
- Carbon monoxide detectors connected to an approved combination system in accordance with NFPA 72.
- Carbon monoxide detectors connected to an approved fire alarm system in accordance with NFPA 72.
- Where approved by the fire code official, carbon monoxide alarms maintained in accordance with the manufacturer’s instructions.
915.3.4 Installation. Carbon monoxide detection shall be installed in accordance with NFPA 72 and the manufacturer’s instructions.
915.4 Carbon monoxide alarms. Carbon monoxide alarms shall comply with Sections 915.4.1 through 915.4.4.
915.4.1 Power source. Carbon monoxide alarms shall receive their primary power from the building wiring where such wiring is served from a commercial source, and when primary power is interrupted, shall receive power from a battery. Wiring shall be permanent and without a disconnecting switch other than that required for overcurrent protection.
Exceptions:
1. Where installed in buildings without commercial power, battery-powered carbon monoxide alarms shall be an acceptable alternative. 2. Carbon monoxide alarms in Group R occupancies shall be permitted to receive their primary power from other power sources recognized for use by NFPA 720. 3. Carbon monoxide alarms in Group R occupancies shall be permitted to be battery-powered or plug-in with a battery backup in existing buildings built prior to January 1, 2011, under any of the following conditions: 3.1. No construction is taking place. 3.2. Repairs or alterations do not result in the removal of interior wall and ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required. 3.3. Repairs or alterations are limited to the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck. 3.4. Work is limited to the installation, alteration or repair of plumbing, mechanical or electrical systems, which do not result in the removal of interior wall or ceiling finishes exposing the structure in areas/spaces where carbon monoxide alarms are required.
915.4.2 Listings. Residential carbon monoxide alarms shall be listed in accordance with UL 2034.
No person shall install, market, distribute, offer for sale or sell any carbon monoxide device in the State of California unless the device and instructions have been approved and listed by the Office of the State Fire Marshal.
CEBC § 25.4 Medium relevance — show source text
See Table R608.3 for tolerances on nominal thicknesses, and minimum core dimensions and maximum spacing of horizontal and vertical cores for waffle-and screen-grid
walls.
k. Tabulated values are applicable to construction where gravity loads bear on top of wall, and conditions where gravity loads from floor construction are transferred to wall
from a wood ledger or cold-formed steel track bolted to side of wall. See Tables R608.6(1), R608.6(2) and R608.6(3).|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound per square inch = 6.895 kPa, 1 square foot = 0.0929 m2.
DR = Design Required.
a. Table is based on ASCE 7 components and cladding wind pressures for an enclosed building using a mean roof height of 35 feet, interior wall area 4, an effective wind area of
10 square feet, topographic factor,Kzt, equal to 1.0, and Risk Category II.
b. Table is based on concrete with a minimum specified compressive strength of 2,500 psi.
c. See Section R608.6.5 for location of reinforcement in wall.
d. Deflection criterion is_L_/240, where_L_ is the height of the wall in inches from the exterior finish ground level to the top of the above-grade wall.
e. Interpolation is not permitted. For intermediate values of basic wind speed, heights of stem wall and above-grade wall, and design lateral soil load, use next higher value.
f. Where No. 4 reinforcing bars at a spacing of 48 inches are specified in the table as indicated by shaded cells, use of bars with a minimum yield strength of 40,000 psi or 60,000
psi is permitted.
g. Other than for No. 4 bars spaced at 48 inches on center, table values are based on reinforcing bars with a minimum yield strength of 60,000 psi. Maximum spacings shown are
the values calculated for the specified bar size. In waffle and screen-grid walls where the bar used is Grade 60 and the size specified in the table, the actual spacing in the wall
shall not exceed a whole-number multiple of 12 inches such as, 12, 24, 36 and 48, that is less than or equal to the tabulated spacing. Vertical reinforcement with a yield
strength of less than 60,000 psi and bars of a different size than specified in the table are permitted in accordance with Section R608.5.4.7 and Table R608.5.4(2).
h. Height of stem wall is the distance from the exterior finish ground level to the top of the slab-on-ground.
i. Where the distance from the exterior finish ground level to the top of the slab-on-ground is equal to or greater than 4 feet, the stem wall shall be laterally supported at the top
and bottom before backfilling. Where the wall is designed and constructed to be continuous with the above-grade wall, temporary supports bracing the top of the stem wall
shall remain in place until the above-grade wall is laterally supported at the top by floor or roof construction.
j. See Table R608.3 for tolerances on nominal thicknesses, and minimum core dimensions and maximum spacing of horizontal and vertical cores for waffle-and screen-grid
walls.
k.CEBC § 304.3.3 Medium relevance — show source text
304.3.3 Criteria for incidental and minor structural alteration, additions, or repairs of pre-1973 code buildings. [OSHPD 1R, 2, 4 & 5] Provisions of this section shall apply to hospital buildings which were originally designed to pre-1973 building codes, and had no major structural alterations, additions or repairs using 1973 California Building Standards Code or later editions with an OSHPD permit. 1. Nonstructural components. Component importance factor, I p , shall be permitted to be 1.0. Exception: Components required for life safety purposes after an earthquake, including emergency, standby or alternative power systems, mechanical smoke removal systems, fire protection sprinkler systems, fire alarm control panels and egress stairways shall have a component importance factor (I p ) of 1.5.
SECTION 305—IN-SITU LOAD TESTS
[BS] 305.1 General. Where used, in-situ load tests shall be conducted in accordance with Section 1708 of the California Building Code .
SECTION 306—ACCESSIBILITY FOR EXISTING BUILDINGS
[DSA-AC] Public buildings, public accommodations, commercial facilities and public housing regulated by the Division of the State Architect-Access Compliance in Title 24, Part 2, California Building Code, Chapter 1, Section 1.9.1 shall comply with Title 24, Part 2, California Building Code, Chapter 11B.
[HCD 1-AC] Accessibility requirements for covered multifamily dwellings, as defined in Chapter 2 of the California Building Code, are promulgated under HCD authority and are located in Chapter 11A of the California Building Code.
SECTION 307—SMOKE ALARMS
307.1 Smoke alarms. Where an alteration, addition, change of occupancy or relocation of a building is made to an existing building or structure of a Group R and I-1 occupancy, the existing building shall be provided with smoke alarms in accordance with the California Fire Code or Section R310 of the California Residential Code .
Exception: Work classified as Level 1 Alterations in accordance with Chapter 7.
SECTION 308—CARBON MONOXIDE DETECTION
308.1 Carbon monoxide detection. Where an addition, alteration, change of occupancy or relocation of a building is made to an existing building, the existing building shall be provided with carbon monoxide detection in accordance with the California Fire Code or Section R311 of the California Residential Code .
3-6 2025 CALIFORNIA EXISTING BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
PROVISIONS FOR ALL COMPLIANCE METHODS
308.2 Carbon monoxide alarms in existing portions of a building. [HCD 1 & HCD 2] Pursuant to Health and Safety Code Section 17926, carbon monoxide detection shall be provided in all existing Group R buildings, as required in Section 915 of the California Building Code or Section R315 of the California Residential Code, as applicable.
CEBC § 1.48 Medium relevance — show source text
16| |4 × 4 ×1/4 wall thickness|120|1.48|2.59|3.50|4.30| |6 double extra strong
0.864 wall thickness|80|0.59|1.46|2.23|2.92| |6 double extra strong
0.864 wall thickness|100|0.73|1.71|2.54|3.29| |6 double extra strong
0.864 wall thickness|110|0.80|1.82|2.69|3.47| |6 double extra strong
0.864 wall thickness|120|0.86|1.93|2.83|3.63| |6 extra strong 0.432
wall thickness|80|0.94|1.90|2.70|3.42| |6 extra strong 0.432
wall thickness|100|1.10|2.13|2.98|3.74| |6 extra strong 0.432
wall thickness|110|1.17|2.22|3.11|3.89| |6 extra strong 0.432
wall thickness|120|1.24|2.34|3.24|4.04| |6 standard 0.280
wall thickness|80|1.14|2.12|2.93|3.64| |6 standard 0.280
wall thickness|100|1.29|2.33|3.19|3.94| |6 standard 0.280
wall thickness|110|1.36|2.43|3.31|4.08| |6 standard 0.280
wall thickness|120|1.42|2.53|3.43|4.22| |5 double extra strong
0.750 wall thickness|80|0.70|1.61|2.40|3.12| |5 double extra strong
0.750 wall thickness|100|0.85|1.86|2.71|3.47| |5 double extra strong
0.750 wall thickness|110|0.91|1.97|2.85|3.63| |5 double extra strong
0.750 wall thickness|120|0.98|2.02|2.99|3.79| |5 extra strong 0.375
wall thickness|80|1.04|2.01|2.83|3.54| |5 extra strong 0.375
wall thickness|100|1.19|2.23|3.09|3.85| |5 extra strong 0.375
wall thickness|110|1.26|2.34|3.22|4.00| |5 extra strong 0.375
wall thickness|20|1.32|2.44|3.34|4.14| |5 standard 0.258
wall thickness|80|1.20|2.19|3.00|3.72| |5 standard 0.258
wall thickness|100|1.34|2.39|3.25|4.00| |5 standard 0.258
wall thickness|110|1.41|2.49|3.37|4.14| |5 standard 0.258
wall thickness|120|1.47|2.58|3.49|4.28| |4 double extra strong
0.674 wall thickness|80|0.80|1.75|2.56|3.
Frequently asked questions
When does the CEBC require carbon monoxide detection in existing buildings?
Carbon monoxide detection is required when an addition, alteration, change of occupancy or relocation is made to an existing building, per CEBC §308, and existing Group R buildings must have CO detection as required by the CBC/Fire Code or the Residential Code (see CBC §915 and R311 for locations, power and interconnection rules).
Do replaced or added exterior wall coverings always need to meet new‑construction rules?
Not always. CEBC §309 requires materials and methods to meet new‑construction requirements (CBC Chapters 14 and 26) only when the added/replaced exterior covering or envelope involves two or more contiguous stories and is more than 15% of the wall area on any side; additional limits apply (for example combustible claddings on un‑sprinklered high‑rises).
Where are the accessibility rules for existing buildings found?
Accessibility for existing buildings is governed by CEBC §306 and incorporates the California Building Code accessibility chapters (Chapter 11B, and Chapter 11A for HCD‑regulated multifamily dwellings), so consult those CBC chapters alongside §306.
More in California Existing Building Code
- Administration and Definitions (Scope, enforcement, code official duties, definitions)
- Provisions for All Compliance Methods (general requirements that apply to all compliance options; Chapter 3 / 3A)
- Seismic retrofit and evaluation (Appendix A and seismic provisions/sections for evaluation and retrofit)
- Referenced Standards and Appendices (Chapter 16 and Appendices A–E, Resource A)
- Repairs (Chapter 4 — repair-specific rules for materials, means of egress, structural, MEP, etc.)
- Alterations — Level 1, Level 2, Level 3 (technical requirements for each alteration level; Chapters 7–9)
- Change of Occupancy and Additions (requirements for occupancy changes and additions; Chapters 10–11)
- Compliance Methods — Prescriptive, Work Area, Performance (Chapters 5, 6–11, 13)
- Relocated Buildings (requirements for buildings moved or relocated; Chapter 14)
- Construction Safeguards (site safety, means of egress and life-safety during construction; Chapter 15)
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