CALGreen · California Green Building Standards Code (CALGreen)
What are the exceptions for accessory structures and live/work units in mixed occupancies?
Under CALGreen **§ 302.1**, mixed-occupancy buildings normally require each occupancy to meet its own green measures — but **accessory structures serving residential buildings** and **live/work units that meet CBC § 508.5** are exceptions: both are handled under the residential compliance path (Chapter 4 and Appendix A4) rather than as mixed occupancies.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
In mixed-occupancy buildings, each portion of the building must follow the green building measures that apply to that occupancy. The California Green Building Standards Code (CALGreen) § 302.1 makes this the baseline rule. CALGreen then lists two narrow exceptions: (1) accessory structures / accessory occupancies serving residential buildings and (2) live/work units that comply with the California Building Code § 508.5 — both of which are handled under the residential compliance path (Chapter 4 and Appendix A4) rather than as mixed occupancies.
If a building contains more than one use, treat each use separately under CALGreen — except that accessory structures serving homes and qualified live/work units are treated as residential and follow Chapter 4 and A4.
Requirements in detail
Controlling text (plain reference)
- The rule and the exceptions appear in CALGreen § 302.1. The text states that each portion of a mixed-occupancy building must comply with the green measures for that occupancy, with two exceptions (accessory structures/occupancies serving residential buildings, and live/work units that comply with CBC § 508.5) which must comply with Chapter 4 and Appendix A4 (residential measures) as applicable.
Decision-relevant dimensions (quick table)
| Decision factor | What to check | Outcome under CALGreen | Code reference |
|---|---|---|---|
| Is the space an accessory structure serving residential units? | Does the structure serve a residential building (detached shed, private garage, carport, small utility building, etc.)? | It follows residential mandatory measures (Chapter 4) and Appendix A4 rather than mixed-occupancy treatment. | § 302.1 |
| Is the unit a live/work unit that meets CBC limits? | Does the unit comply with CBC § 508.5 (e.g., size/percentage/location limits)? | If it complies with CBC § 508.5, CALGreen does not consider it a mixed occupancy — it follows Chapter 4 and Appendix A4. If it does not meet CBC § 508.5, treat as mixed occupancy. | § 302.1 (CALGreen) and CBC § 508.5 |
| If neither exception applies | N/A | Each portion must meet the green measures for its specific occupancy. | § 302.1 |
What "comply with Chapter 4 and Appendix A4" means here
- CALGreen directs accessory structures and qualifying live/work units to the residential measures in Chapter 4 and Appendix A4 (these contain the mandatory and optional residential green measures). The CALGreen text itself establishes the routing; the detailed residential requirements remain in those chapters/appendices.
Live/work qualification (key thresholds from CBC)
Because CALGreen's exception for live/work units is explicitly tied to the California Building Code, confirm the CBC limits when evaluating whether a live/work unit escapes mixed-occupancy treatment. Notable CBC § 508.5 thresholds include: the unit area limit and the nonresidential-area limit and location restrictions (see CBC § 508.5 for full detail).
Exceptions & special cases
- Accessory structures serving residential buildings: Detached or accessory occupancies that serve residential buildings are not treated as separate mixed-occupancy portions for CALGreen compliance; they follow Chapter 4 and Appendix A4 instead. This is an HCD-tagged exception in § 302.1.
- Live/work units: A live/work unit that meets the CBC § 508.5 requirements is explicitly not considered a mixed occupancy for CALGreen purposes and must comply with Chapter 4 and Appendix A4. Verify CBC § 508.5 limits (area, percent nonresidential, location) to determine qualification.
- If a live/work unit fails CBC limits: If the unit exceeds CBC § 508.5 thresholds or otherwise does not meet those provisions, CALGreen’s exception does not apply — treat the nonresidential portion and residential portion under their respective occupancy rules per § 302.1.
Common mistakes
- Treating every unit with a business use as a live/work unit: only units that meet CBC § 508.5 qualify for the CALGreen exception. Always confirm the CBC limits rather than assuming.
- Applying nonresidential CALGreen measures to small accessory structures that serve residences. If an accessory structure serves a residential building, follow Chapter 4 / Appendix A4 per § 302.1, not the nonresidential chapter.
- Forgetting jurisdictional tags: the CALGreen text marks these exceptions with [HCD], indicating they come from Housing and Community Development scope — useful when coordinating with enforcing agencies.
Worked example — concrete scenario
Scenario: A two-story building contains (A) four dwelling units and (B) one attached live/work unit. The live/work unit is 1,200 sq ft total, with 600 sq ft used for a studio (nonresidential) on the ground floor.
Step 1 — Is the building mixed occupancy? CALGreen § 302.1 says treat each portion by its occupancy — but check exceptions.
Step 2 — Does the live/work unit qualify under CBC § 508.5? Check CBC limits: maximum unit area (≤ 3,000 sq ft) and nonresidential portion (≤ 50%) and nonresidential on the first/main floor. In this example: 1,200 sq ft ≤ 3,000 sq ft, 600 sq ft is 50% of the unit, and the nonresidential space is on the ground floor — so the unit meets CBC § 508.5 thresholds.
Step 3 — Result under CALGreen: Because the live/work unit meets CBC § 508.5, CALGreen § 302.1 does not treat that unit as mixed occupancy. The live/work unit and the accessory structures (if any) will follow Chapter 4 and Appendix A4 residential measures rather than separate mixed-occupancy measures.
If, instead, the studio had been 800 sq ft (≈66.7%), the CBC § 508.5 limit would be exceeded and the live/work unit would not qualify for the CALGreen exception — then treat the portions under mixed-occupancy rules per § 302.1.
Related provisions
- CALGreen § 302.1 (Mixed occupancy buildings — rule and exceptions).
- CALGreen § 303.1 (Phased projects — scoping for shell buildings and tenant improvements) — relevant when a shell is constructed and tenant improvements may change occupancy mix.
- CALGreen § 304.1 (Voluntary tiers) — if a local jurisdiction adopts Tier requirements, occupancy routing may affect which tier measures apply.
- California Building Code § 508.5 (Live/work units — definitions and limits referenced by CALGreen exception).
Code references
Grounded in the retrieved California Green Building Standards Code (CALGreen) — click a citation to read the verbatim passage:
CALGreen § 301.5 High relevance — show source text
301.5 Health Facilities. [OSHPD 1, 2 & 4] Health facilities under the jurisdiction of the Office of Statewide Health Planning and Development (OSHPD) are required to comply with the mandatory measures prescribed in Section 5.304, Outdoor Water Use. Compliance with Section 5.304, as adopted by the Building Standards Commission, is enforced by the local agency having jurisdiction. Evidence of local approval shall be submitted to OSHPD prior to issuance of plan approval or a building permit.
2025 CALIFORNIA GREEN BUILDING STANDARDS CODE 3-3
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GREEN BUILDING
SECTION 302—MIXED OCCUPANCY BUILDINGS
302.1 Mixed occupancy buildings. In mixed occupancy buildings, each portion of a building shall comply with the specific green building measures applicable to each specific occupancy.
Exceptions:
- [HCD] Accessory structures and accessory occupancies serving residential buildings shall comply with Chapter 4 and Appendix A4, as applicable.
- [HCD] For the purposes of CALGreen, live/work units, complying with Section 508.5 of the California Building Code, shall not be considered mixed occupancies. Live/work units shall comply with Chapter 4 and Appendix A4, as applicable.
SECTION 303—PHASED PROJECTS
303.1 Phased projects. For shell buildings and others constructed for future tenant improvements, only those code measures relevant to the building components and systems considered to be new construction (or newly constructed) shall apply.
303.1.1 Initial tenant improvements. The provisions of this code shall apply only to the initial tenant improvements to a project. Subsequent tenant improvements shall comply with the scoping provisions in Section 301.3 nonresidential additions and alterations.
SECTION 304—VOLUNTARY TIERS
304.1 Purpose. Voluntary tiers are intended to further encourage building practices that improve public health, safety and general welfare by promoting the use of building concepts which minimize the building’s impact on the environment and promote a more sustainable design.
304.1.1 Tiers. The provisions of Divisions A4.6 and A5.6 outline means, in the form of voluntary tiers, for achieving enhanced construction levels by incorporating additional measures for residential and nonresidential new construction. Voluntary tiers may be adopted by local governments and, when adopted, enforced by local enforcing agencies. Buildings complying with tiers specified for each occupancy contain additional prerequisite and elective green building measures necessary to meet the threshold of each tier. See Section 101.7 of this code for procedures and requirements related to local amendments, additions or deletions, including changes to energy standards.
[BSC & HCD] Where there are practical difficulties involved in complying with the threshold levels of a tier, the enforcing agency may grant modifications for individual cases. The enforcing agency shall first find that a special individual reason makes the strict letter of the tier impractical and that modification is in conformance with the intent and purpose of the measure. The details of any action granting modification shall be recorded and entered in the files of the enforcing agency.
SECTION 305 [OSHPD 1]— CALGreen TIER 1 AND CALGreen TIER 2
305.1 CALGreen Tier 1 and CALGreen Tier 2 buildings contain voluntary green building measures necessary to meet the threshold of each level.
CALGreen § 301.3.2 High relevance — show source text
301.3.2 Waste diversion. The requirements of Section 5.408 shall be required for additions and alterations whenever a permit is required for work.
301.4 Mandatory measures for public schools and community colleges. [DSA-SS] New building construction and site work on a new or existing site shall comply with Section 301.4.
301.4.1 Building and site construction on a new site shall comply with Chapter 5 as adopted by DSA-SS.
301.4.2 Work on an existing site shall comply with Section 301.4.2.
301.4.2.1 Newly constructed site work shall comply with Chapter 5 as adopted by DSA-SS.
301.4.2.2 Newly constructed buildings shall comply with Chapter 5 as adopted by DSA-SS and Section 301.4.3.
301.4.2.3 Additions to existing buildings shall comply with Section 301.4.3.
301.4.2.4 Rehabilitated landscape areas shall comply with Sections 5.304.6 and 5.106.12.
301.4.2.5 Alterations and additions to existing parking facilities shall comply with Section 5.106.5.6.4. Additions to existing parking facilities shall comply with Section 5.106.12.
301.4.2.6 Alterations and additions to existing buildings shall comply with Sections 5.105.1, 5.106.5.6.5, 5.409, and 5.506.3.
301.4.3 Minimum rehabilitated landscape area requirement. A minimum rehabilitated landscape area equal to 75 percent of the footprint area of the building shall comply with Section 5.304.6 and Section 5.106.12. New buildings or additions to existing buildings less than 1,600 square feet shall not be required to comply with Section 301.4.3.
301.5 Health Facilities. [OSHPD 1, 2 & 4] Health facilities under the jurisdiction of the Office of Statewide Health Planning and Development (OSHPD) are required to comply with the mandatory measures prescribed in Section 5.304, Outdoor Water Use. Compliance with Section 5.304, as adopted by the Building Standards Commission, is enforced by the local agency having jurisdiction. Evidence of local approval shall be submitted to OSHPD prior to issuance of plan approval or a building permit.
2025 CALIFORNIA GREEN BUILDING STANDARDS CODE 3-3
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GREEN BUILDING
SECTION 302—MIXED OCCUPANCY BUILDINGS
302.1 Mixed occupancy buildings. In mixed occupancy buildings, each portion of a building shall comply with the specific green building measures applicable to each specific occupancy.
Exceptions:
- [HCD] Accessory structures and accessory occupancies serving residential buildings shall comply with Chapter 4 and Appendix A4, as applicable.
- [HCD] For the purposes of CALGreen, live/work units, complying with Section 508.5 of the California Building Code, shall not be considered mixed occupancies. Live/work units shall comply with Chapter 4 and Appendix A4, as applicable.
SECTION 303—PHASED PROJECTS
CALGreen § 508.2. High relevance — show source text
Exception s : 1. Dwelling or sleeping units that include an office that is less than 10 percent of the area of the dwelling unit are permitted to be classified as dwelling units with accessory occupancies in accordance with Section 508.2. 2. Live/work units complying with the requirements of Section 508.5 shall be permitted to be constructed as one- and two- family dwellings or townhouses in accordance with the California Residential Code, as applicable.
508.5.1 Limitations. The following shall apply to live/work areas:
- The live/work unit is permitted to be not greater than 3,000 square feet (279 m [2] ) in area.
- The nonresidential area is permitted to be not more than 50 percent of the area of each live/work unit.
- The nonresidential area function shall be limited to the first or main floor only of the live/work unit.
508.5.2 Occupancies. Live/work units shall be classified as a Group R-2 occupancy. Separation requirements found in Sections 420 and 508 shall not apply within the live/work unit where the live/work unit is in compliance with Section 508.5. Nonresidential uses that would otherwise be classified as either a Group H or S occupancy shall not be permitted in a live/work unit.
Exception: Storage shall be permitted in the live/work unit provided that the aggregate area of storage in the nonresidential portion of the live/work unit shall be limited to 10 percent of the space dedicated to nonresidential activities.
[BE] 508.5.3 Means of egress. Except as modified by this section, the means of egress components for a live/work unit shall be designed in accordance with Chapter 10 for the function served.
Exception: Residential areas of live/work units constructed in accordance with the California Residential Code shall not be required to comply with Chapter 10.
[BE] 508.5.4 Egress capacity. The egress capacity for each element of the live/work unit shall be based on the occupant load for the function served in accordance with Table 1004.5.
[BE] 508.5.5 Spiral stairways. Spiral stairways that conform to the requirements of Section 1011.10 shall be permitted.
[BE] 508.5.6 Vertical openings. Floor openings between floor levels of a live/work unit are permitted without enclosure.
[F] 508.5.7 Fire protection. Live/work units in buildings constructed in accordance with this code shall be provided with all of the following:
An automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2.
Smoke alarms in accordance with Section 907.2.11.
Where required by Section 907.2.9.2, a manual fire alarm system.
Live/work units in buildings constructed in accordance with the California Residential Code shall be provided with an automatic sprinkler system and smoke alarms. The automatic sprinkler system shall comply with California Residential Code Section R309, and smoke alarms shall comply with California Residential Code Section 310.
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GENERAL BUILDING HEIGHTS AND AREAS
508.5.8 Structural. Floors within a live/work unit shall be designed for the live loads in Table 1607.1, based on the function within the space.
CALGreen § 503.1. High relevance — show source text
Exception: Special provisions of Section 510 shall permit occupancies at building heights and number of stories other than provided in Section 503.1.
508.4.4 Separation. Individual occupancies shall be separated from adjacent occupancies in accordance with Table 508.4.
508.4.4.1 Construction. Required separations shall be fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both, so as to completely separate adjacent occupancies. Mass timber elements serving as fire barriers or horizontal assemblies to separate occupancies in Type IV-B or IV-C construction shall be separated from the interior of the building with an approved thermal barrier consisting of gypsum board that is not less than [1] / 2 inch (12.7 mm) in thickness or a material that is tested in accordance with and meets the acceptance criteria of both the Temperature Transmission Fire Test and the Integrity Fire Test of NFPA 275.
Exception: A thermal barrier shall not be required on the top of horizontal assemblies serving as occupancy separations.
508.5 Live/work units. Live/work units shall comply with one of the following:
- For a live/work unit located in a building constructed in accordance with this code, both the residential and nonresidential portions of the live/work unit shall comply with Sections 508.5 through 508.5.11.
- For a live/work unit located in a building constructed in accordance with the California Residential Code, the nonresidential portion of the live/work unit shall comply with Sections 508.5.1 through 508.5.11, and the residential portion of the live/work unit shall be constructed in accordance with the California Residential Code and Section 508.5.7.
Exception s : 1. Dwelling or sleeping units that include an office that is less than 10 percent of the area of the dwelling unit are permitted to be classified as dwelling units with accessory occupancies in accordance with Section 508.2. 2. Live/work units complying with the requirements of Section 508.5 shall be permitted to be constructed as one- and two- family dwellings or townhouses in accordance with the California Residential Code, as applicable.
508.5.1 Limitations. The following shall apply to live/work areas:
- The live/work unit is permitted to be not greater than 3,000 square feet (279 m [2] ) in area.
- The nonresidential area is permitted to be not more than 50 percent of the area of each live/work unit.
- The nonresidential area function shall be limited to the first or main floor only of the live/work unit.
508.5.2 Occupancies. Live/work units shall be classified as a Group R-2 occupancy. Separation requirements found in Sections 420 and 508 shall not apply within the live/work unit where the live/work unit is in compliance with Section 508.5. Nonresidential uses that would otherwise be classified as either a Group H or S occupancy shall not be permitted in a live/work unit.
Exception: Storage shall be permitted in the live/work unit provided that the aggregate area of storage in the nonresidential portion of the live/work unit shall be limited to 10 percent of the space dedicated to nonresidential activities.
[BE] 508.5.3 Means of egress. Except as modified by this section, the means of egress components for a live/work unit shall be designed in accordance with Chapter 10 for the function served.
CALGreen § 1.1.3 High relevance — show source text
1.1.3 Scope. The provisions of this code shall apply to the construction, alteration, movement, enlargement, replacement, repair, equip- ment, use and occupancy, location, maintenance, removal and demolition of every detached one- and two-family dwelling and townhouse not more than three stories above grade plane in height with a separate means of egress and structures accessory thereto throughout the State of California.
Exceptions: 1. Live/work units complying with the requirements of Section 508.5 of the California Building Code shall be permitted to be constructed as one- and two-family dwellings or townhouses in accordance with this code, as applicable. Fire suppression required by Section 508.5.7 of the California Building Code when constructed under the California Residential Code for one- and two-family dwellings shall conform to Section 903.3.1.3 of the California Building Code. 2. Owner-occupied lodging houses with five or fewer guestrooms shall be permitted to be constructed in accordance with the California Residential Code for one- and two-family dwellings when equipped with a fire sprinkler system in accordance with Section R309.
1.1.3.1 Classification. Structures or portions of structures shall be classified with respect to occupancy in one or more of the groups listed in Chapter 3 of the California Building Code. A room or space that is intended to be occupied at different times for different purposes shall comply with all of the requirements that are applicable to each of the purposes for which the room or space will be occupied. Structures with multiple occupancies or uses shall comply with Section 508 of the California Building Code. Where a struc- ture is proposed for a purpose that is not specifically provided for in this code, such structure shall be classified in the group that the occupancy most nearly resembles, according to the fire safety and relative hazard involved in accordance with this code or the Cali- fornia Building Code.
Note: Live/work units complying with the requirements of Section 508.5 of the California Building Code are classified as a Group R-2 occupancy and are permitted to be constructed as one- and two-family dwellings or townhouses in accordance with this code.
1.1.3.1.1 Utility and Miscellaneous Group U. Buildings and structures of an accessory character and miscellaneous structures not classified in any specific occupancy shall be constructed, equipped and maintained to conform to the requirements of this code commensurate with the fire and life hazard incidental to their occupancy. Group U shall include, but not be limited to, the following:
Agricultural buildings
Aircraft hangars, accessory to a one- or two-family residence (see Section 412.5 of the California Building Code)
Barns
Carports
Fences more than 7 feet (2134 mm) high
Grain silos, accessory to a residential occupancy
Greenhouses
Livestock shelters
Private garages
Retaining walls
Sheds
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DIVISION I CALIFORNIA ADMINISTRATION
Stables
Tanks
Towers
CALGreen § 803.13 High relevance — show source text
Incidental uses 509 Interior finishes Table 803.13, 804 Live load Table 1607.1 Means of egress Aisles 1018.3
Stairway, exit access 1019 Travel distance 1006.3, 1017.2,
1006.2.1
Mixed occupancies 508.2, 508.3, 508.4 Accessory 303.1.2, 508.2 Ambulatory care facilities 422 Assembly 303.1.2
Assembly spaces 1030 Exit signs 1013.1 Guards 1015.2, 1030.17 Main exit 1030.3
Open air 1005.3.1, 1005.3.2, 1006.3, 1009.6.4, 1019.3, 1027, 1030.6.2 Panic hardware 1010.2.8, 1010.4.1 Smoke-protected 1005.3.1, 1005.3.2, 1006.3, 1009.6.4, 1019.3, 1027, 1030.6.2 Travel distance 1006.2.1, 1006.3, 1017.2, 1030.7 Mixed occupancies 508.3, 508.4 Accessory 508.2 Education 303.1.3
Live/work units 508.5 Mall buildings 402 Other occupancies 303.1.1, 303.1.2, 303.1.3 Parking below/above 510.7, 510.9 Religious facilities 303.1.4 Special mixed 510.2 Motion picture theaters 409, 507.12 Occupancy exceptions 303.1.1, 303.1.2, 303.1.3, 303.1.4, 305.1.1, 305.2.1 Plumbing fixtures Chapter 29 Risk category Table 1604.5 Seating, fixed (see Seating, Fixed) Seating, open-air assembly seating 1030.6.3 Seating, smoke-protected 1030.6.2 Sprinkler protection 410, 504.3, 506.2, 507.12, 507.4, 507.6, 507.7, 903.2.1 Stages and platforms 410 Standpipes 905.3.2, 905.5.1 Unlimited area 507.12, 507.4, 507.4.1, 507.6, 507.7 Assisted Living (see Group I-1 and Group R-4) 308.2, 310.5, 420 Atmospheric Ice Loads 1614 Atrium 404
Alarms and detection 404.4, 907.2.15 Enclosure 404.6, 707.3.6 Interior finish 404.8 Means of egress 404.9, 404.10, 404.11, 1006.3.2, 1017.3, 1019.3, 1023.2,
1028.2
Smoke control 404.5, 909 Sprinkler protection 404.3 Standby power 404.7 Travel distance 404.9, 1006.2.1, 1006.3, 1017.2
Use 404.2
Attic 202
CALGreen § 11B-217 High relevance — show source text
Telephone 1140A, 11B-217, 11B-704 Toilet and bathing facilities 1127A, 1134A, 11B-213, Chapter 11B Division 6 Transient lodging 1102A, 11B-224, 11B- 806 Transportation facilities 11B-218, 11B-810
Turning space 1009.6.5, 1026.6, 11B-304 Two-way communication systems 1009.8, 11B-230, 11B-708 Valet parking 11B-209.4 Visible alarms 907.5.2.3 Wading pools and spas 11B-242, 11B-1009 Walking surfaces 11B-403 Walks, sidewalks 1113A Washing machines and clothes dryers 11B-214, 11B-611 Windows 1126A, 11B-229 Accessible Means of Egress 1009, 11B-207 Alarms/emergency warning systems/two way communication systems 1009.12 Areas of refuge (see Area of Refuge) Assembly 1009.1, 1030.8 Elevators 1009.2.1, 1009.4, 1009.8 Existing building 1009.1 Exterior area for assisted rescue (see Exterior Area for Assisted Rescue) Horizontal exit (see Horizontal Exit) Mezzanine 1009.1
Platform lift 1009.5 Required 1009.1 Signage 1009.9, 1009.11, 3002.3 Stairways 1009.3 Accessory Occupancies As occupancy exceptions 303.1.2, 303.1.4, 305.1.1, 311.1.1, 312.1 Live/work units 508.5 Mixed occupancy buildings 508.2 Height 508.2.2 Occupancy classification 508.2.1 Separations 508.2.4 Unlimited area buildings 507.1.1 Accreditation Body 2303.1.1, 2303.1.9.1 Addition 101.4.7, D103.1 Means of egress 3301.4, 3310 Address Identification 502.1 Adjusted Construction Costs 11B-106.5, 11B-
202 .4 Administration Chapter 1, Divisions I and II
AAC Masonry 2103.1, 2108.1 Access Openings Attic 1209.2
Crawl space 1209.1 Doors 712.1.13.2 Fire damper 717.4 Fire department 402.7.5 Mechanical appliances 1209.3 Refuse/laundry chutes 713.13.3 Accessibility 1009, Chapter 11A, 11B Accessible means of egress 1009, 11B- 207
CALGreen § 508.5 High relevance — show source text
Structures with multiple occupancies or uses shall comply with Section 508 of the California Building Code. Where a struc-_ ture is proposed for a purpose that is not specifically provided for in this code, such structure shall be classified in the group that the occupancy most nearly resembles, according to the fire safety and relative hazard involved in accordance with this code or the Cali- fornia Building Code.
Note: Live/work units complying with the requirements of Section 508.5 of the California Building Code are classified as a Group R-2 occupancy and are permitted to be constructed as one- and two-family dwellings or townhouses in accordance with this code.
1.1.3.1.1 Utility and Miscellaneous Group U. Buildings and structures of an accessory character and miscellaneous structures not classified in any specific occupancy shall be constructed, equipped and maintained to conform to the requirements of this code commensurate with the fire and life hazard incidental to their occupancy. Group U shall include, but not be limited to, the following:
Agricultural buildings
Aircraft hangars, accessory to a one- or two-family residence (see Section 412.5 of the California Building Code)
Barns
Carports
Fences more than 7 feet (2134 mm) high
Grain silos, accessory to a residential occupancy
Greenhouses
Livestock shelters
Private garages
Retaining walls
Sheds
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DIVISION I CALIFORNIA ADMINISTRATION
Stables
Tanks
Towers
1.1.3.2 Regulated buildings, structures and applications. The model code, state amendments to the model code and/or state amendments where there are no relevant model code provisions shall apply to detached one- and two-family dwellings, lodging houses, live/work units, townhouses and structures accessory thereto. State agencies with regulatory authority as specified in Sections 1.2 through 1.14, except where modified by local ordinance pursuant to Section 1.1.8. When adopted by a state agency, the provisions of this code shall be enforced by the appropriate enforcing agency, but only to the extent of authority granted to such agency by the state legislature.
Note: See “How to Distinguish Between Model Code Language and California Amendments” following the Preface. 1. One- and two-family dwellings, townhouses, employee housing, factory-built housing and other types of dwellings contain- ing sleeping accommodations with common toilets or cooking facilities. See Section 1.8.2.1.1. 2. Permanent buildings and permanent accessory buildings or structures constructed within mobilehome parks and special occupancy parks regulated by the Department of Housing and Community Development. See Section 1.8.2.1.3. 3. Applications regulated by the Office of the State Fire Marshal include, but are not limited to, the following in accordance with Section 1.11:
CALGreen § 1009.5 High relevance — show source text
Platform lift 1009.5 Required 1009.1 Signage 1009.9, 1009.11, 3002.3 Stairways 1009.3 Accessory Occupancies As occupancy exceptions 303.1.2, 303.1.4, 305.1.1, 311.1.1, 312.1 Live/work units 508.5 Mixed occupancy buildings 508.2 Height 508.2.2 Occupancy classification 508.2.1 Separations 508.2.4 Unlimited area buildings 507.1.1 Accreditation Body 2303.1.1, 2303.1.9.1 Addition 101.4.7, D103.1 Means of egress 3301.4, 3310 Address Identification 502.1 Adjusted Construction Costs 11B-106.5, 11B-
202 .4 Administration Chapter 1, Divisions I and II
AAC Masonry 2103.1, 2108.1 Access Openings Attic 1209.2
Crawl space 1209.1 Doors 712.1.13.2 Fire damper 717.4 Fire department 402.7.5 Mechanical appliances 1209.3 Refuse/laundry chutes 713.13.3 Accessibility 1009, Chapter 11A, 11B Accessible means of egress 1009, 11B- 207
Accessible routes Chapter 11A, 11B- 206, Chapter 11B Division 4, 11B-402 Amusement rides 11B-234, 11B-1002 Application 1.9.1, Chapter 11B Division 1 Assembly 1009.1 Assembly areas 11B-221, 11B-802 Assistive listening systems 11B-219, 11B-706 Automatic teller machines, fare machines and point-of-sale devices 11B-220, 11B-707 Bathroom 1127A, 1134A, 11B-806.2.4, 11B-809.10 Benches 11B-903
Bus stops 11B-209 Changes in level 1111A, 1121A, 1131A, 11B-303 Clear floor or ground space Chapter 11A, 11B-305 Covered multifamily dwellings Chapter 11A Curb ramps, blended transitions and islands 1112A, 11B-406 Destination-oriented elevators
11B-206.6, 11B-411 Detectable warnings 1112A.9, 1116A.5, 11B-247, 11B-705 Detention and correctional
facilities 11B-232, 11B-807 Dimensions for adults and
children 11B-102
CALGreen § 3.6 High relevance — show source text
TABLE R302.3.6—DWELLING-SHARED ACCESSORY AND/OR CARPORT SEPARATION Col2 SEPARATION MATERIAL From the dwelling units and attics Not less than1/2-inch gypsum board or equivalent applied to the
accessory room side wallFrom habitable rooms above or below the shared accessory room Not less than5/8-inch Type X gypsum board or equivalent Structures supporting floor/ceiling assemblies used for separation
required by this sectionNot less than1/2-inch gypsum board or equivalent For SI: 1 inch = 25.4 mm. For SI: 1 inch = 25.4 mm. R302.3.6.1 Opening protection. Openings from a shared accessory room or area directly into a room used for sleeping purposes shall not be permitted. Other openings between the shared accessory room or area and dwelling units 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 a fire door assembly with a 20-minute fire-protection rating, equipped with a self-closing or automatic-closing device.
R302.3.6.2 Duct penetration. Ducts penetrating the walls or ceilings separating the dwelling from the shared accessory room shall be constructed of sheet steel not less than No. 26 gage (0.48 mm) or other approved material and shall not have openings into the shared accessory room.
R302.3.6.3 Other penetrations. Penetrations through the walls, ceiling and floor-level separation required in Section R302.3.6 shall be protected as required by Section R302.11, Item 4.
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:
- 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 mortar shall be permitted where installed to the full thickness of the wall or floor assembly or the thickness required to maintain the fire-resistance rating, provided that both of the following are complied with: 1.1.1. The nominal diameter of the penetrating item is not more than 6 inches (152 mm). 1.1.2. The area of the opening through the wall does not exceed 144 square inches (92 900 mm [2] ).
3-26 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
BUILDING PLANNING
CALGreen § 803.13 High relevance — show source text
Interior finishes Table 803.13, 804 Live load Table 1607.1
Live/work units 508.5 Means of egress Aisles 1018.5
Corridors 1020.2, 1020.3
Doors 1010.1.1 Emergency escape and rescue 1031.2
Exit signs 1013.1, 1013.2 Single exits 1006.3 Stairway, exit access 1019 Travel distance 1006.3.3, 1017.2,
1006.2.1
Mixed occupancies 508.3, 508.4 Accessory 508.2, G112.1 Live/work units 508.5 Parking, private 406.2.8, 406.3 Parking below/above 510.4, 510.7, 510.9
Special mixed 510.2
INDEX-16 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
INDEX
Means of egress 3310 Protection of pedestrians 3306 Sanitary facilities 3305 Site work 3304
Sprinkler protection 3312 Standpipes 3308.1.1, 3311 Temporary use of streets, alleys and public property 3308 Safety Glazing 716.1.2.1, 2406 Sallyport 408.3.7 Schools
[see Educational Occupancy (Group E)] Seating Accessibility Chapter 11B Tables 1030.9, 1030.13.1 Seating, Fixed 1030 Accessibility Chapter 11B Aisles 1030.9, 1030.13 Bleachers (see Bleachers) Grandstands (see Grandstands) Guards 1030.17
Live load Table 1607.1
Occupant load 1004.6 Stability 1030.15 Temporary 108 Security Glazing 408.7 Security Grilles 402.8.8, 1010.3.4 Seismic 1613
Cold-formed steel 2204.2, 2206.1.1 Construction documents 107,
1603.1.5 Earthquake recording equipment Appendix L Fire resistance 704.11 Geotechnical investigation 1803.5.11, 1803.5.12 Glazing 2404 Loads 1613
Masonry 2106 Membrane structure 3102.7 Seismic design category 1613.2 Seismic detailing 1604 Site class 1613.2
Special inspection 1705.13 Statement of special inspections 1704.3.2
Steel 2202.2, 2206.2 Structural observations 1704.6.1 Structural testing 1705.14 Wood 2305, 2308.10.10, 2308.10.6,
2308.10.8 Service Sinks 11B-606, Chapter 29 Service Station (see Motor Fuel-Dispensing Facilities) Shaft Enclosure (see Vertical Opening Protection) 713 Continuity 713.11, 713.12, 713.5 Elevators 713.14
Exceptions 712.1, 1019, 1023 Exterior walls 713.6
CALGreen § 0.5 Medium relevance — show source text
in.|≤ 100 sq. in. =
D-H-90
>100 sq. in.=
D-H-W-90|Not
Permitted|2|Not
Permitted|W-120| |Double fire walls
constructed in
accordance with
NFPA 221|2|1|1|100 sq. in.|≤ 100 sq. in. =
D-H-60
> 100 sq. in. =
D-H-W-60|Not
Permitted|1|Not
Permitted|W-60| |Enclosures for
shafts, interior exit
stairways and inte-
rior exit ramps.|2|2|11/ 2|100 sq. in.b|≤100 sq. in. =
D-H-90
> 100 sq. in.=
D-H-T-W-90|Not
Permitted|2|Not
Permitted|W-120| |Horizontal exits in
fire wallsg|4|4|3|100 sq. in.|≤100 sq. in. =
D-H-180
> 100 sq. in.=
D-H-W-240|Not
Permitted|4|Not
Permitted|W-240| |Horizontal exits in
fire wallsg|3|3|3d|100 sq. in.|≤100 sq. in. =
D-H-180
> 100 sq. in.=
D-H-W-180|Not
Permitted|3|Not
Permitted|W-180| |Fire barriers having
a required fire-
resistance rating of
1 hour: Enclosures
for shafts, exit
access stairways,
exit access ramps,
interior exit stair-
ways and interior
exit ramps; and exit
passageway walls|1|1|1|100 sq. in.|≤100 sq. in. =
D-H-60
>100 sq. in.=
D-H-T-W-60|Not
Permitted|1|Not
Permitted|W-60| |||||||Fire protection|Fire protection||| |Other fire barriers|1|1|3/ 4|Maximum
size tested|D-H-45|3/ 4
h|3/ 4
h|D-H-45h|D-H-45h| |Fire partitions:
Corridor walls|1|1|1/ 3
a|Maximum
size tested|D-20|3/ 4
a|3/ 4
a|D-H-OH-45|D-H-OH-45| |Fire partitions:
Corridor walls|0.5|0.5|1/ 3
a|Maximum
size tested|D-20|1/ 3|1/ 3|D-H-OH-20|D-H-OH-20|7-28 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
FIRE AND SMOKE PROTECTION FEATURES
|TABLE 716.1(2)—OPENING FIRE PROTECTION ASSEMBLIES,
Frequently asked questions
Are accessory garages and sheds always treated as residential under CALGreen §302.1?
Yes — accessory structures and accessory occupancies that serve residential buildings are routed to the residential compliance path (Chapter 4 and Appendix A4) by § 302.1. Confirm they truly serve the residential use; if they serve a nonresidential occupancy, the exception does not apply.
If a live/work unit has 51% nonresidential area, what happens?
A unit exceeding the CBC § 508.5 limits (for example, nonresidential area > 50%) does not qualify for the CALGreen exception in § 302.1 and must be treated as mixed occupancy (each portion complies with the measures for its occupancy).
Where do I look for the specific residential green measures that apply to these exceptions?
The specific measures are in CALGreen Chapter 4 and Appendix A4 (residential mandatory and voluntary measures); § 302.1 directs accessory structures and qualifying live/work units to those chapters.
Who tagged these exceptions as [HCD], and why does that matter?
CALGreen shows the exceptions with [HCD], indicating they were adopted as housing-related amendments — useful to know when coordinating enforcement or jurisdictional questions with the Department of Housing and Community Development.
If a tenant improvement converts a residential accessory space into a commercial use, how does §302.1 apply?
If the use changes so the space no longer serves the residential building (or a live/work unit no longer meets CBC § 508.5), the CALGreen exception no longer applies and the space must comply with the green measures for its new occupancy per § 302.1.
More in California Green Building Standards Code (CALGreen)
- Administration (Chapter 1)
- Nonresidential Voluntary Measures (Appendix A5 — divisions A5.1–A5.6, electives & verification)
- Residential Mandatory Measures — Planning & Design; Energy; Water; Materials; Environmental Quality (Chapter 4)
- Definitions (Chapter 2)
- Voluntary Standards for Health Facilities (Appendix A6 / OSHPD guidance)
- Green Building – scope, mixed occupancies, phased projects (Chapter 3)
- Residential Voluntary Measures (Appendix A4 — divisions A4.1–A4.6, tiers & model ordinance)
- Nonresidential Mandatory Measures — Planning & Design; Energy; Water; Materials; Environmental Quality (Chapter 5)
- Compliance verification, construction documents & checklists (Section 102, Chapter 7, Appendix checklists)
- Referenced Organizations and Standards (Chapter 6)
- Voluntary Tiers and CALGreen Tier 1 / Tier 2 (performance tiers, thresholds)
- Installer and Special Inspector Qualifications (Chapter 7)
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