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Chapter 12 — INTERIOR ENVIRONMENT

California Building Code (Title 24, Part 2) · 2022 edition · updated 2026-09-12 · California

Italicized text is a California amendment to the model code, as printed in the official publication.

(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user.

See Chapter 1 for state agency authority and building applications.)

Adopting agency BSC BSC-
CG		 SFM HCD DSA OSHPD BSCC DPH AGR DWR CEC CA SL SLC
Adopting agency BSC BSC-
CG		 SFM 1 2 1/AC AC SS SS/CC 1 1R 2 3 4 5 5 5 5 5 5 5 5 5
Adopt entire chapter X X
Adopt entire chapter as
amended (amended
sections listed below)		 X X X X X X X X X
Adopt only those
sections that are
listed below		 X X X X X X
Chapter / Section
1202.1 X X
1202.2.1 X X
1202.3 X X
1202.4.1.3 X
1202.5 X X
1202.5.2.1 X X
1202.6 X
1203.1,
Exceptions 2 & 4		 X X
1203.1,Exception 3 X X X X X X
Table 1203.3.1 X
1203.4.1.1 X
1203.4.2 X
1204.1 X X
1204.4.1 X X
1204.6 X
1204.7 X
1204.7.1 X
1205 X
1206.3,Exception X X
1206.4 X X
1206.5 X
1208.1 X
1208.2 X X X X X X
1208.2, Exception 5 X X X X
1208.2, Exception 6 X
1208.4 X
1209 X
1209.1.1 X
1210.2 X X X X X
1211 – 1211.6 X X
1212 X
Table 1224.4.6.5 X X X X X X
1224 X
1225 X
1226 X
1227 X
1228 X
1230 X
1231 X
1235 X
1236 X
1237 X

(continued)

Copyright © 2022 by, or licensed to, International Code Council, Inc. (ALL RIGHTS RESERVED); licensed to California Building Standards Commission pursuant to License Agreement. No further reproductions is authorized. Any unauthorized reproduction or distribution is a violation of the federal copyright act and the license agreement, and subject to civil and criminal penalties thereunder.

CALIFORNIA BUILDING CODE – MATRIX ADOPTION TABLE

CHAPTER 12 – INTERIOR ENVIRONMENT—continued

Adopting agency BSC BSC-
CG		 SFM HCD DSA OSHPD BSCC DPH AGR DWR CEC CA SL SLC
Adopting agency BSC BSC-
CG		 SFM 1 2 1/AC AC SS SS/CC 1 1R 2 3 4 5 5 5 5 5 5 5 5 5
Adopt entire chapter X X
Adopt entire chapter
as amended
(amended sections
listed below)		 X X X X X X X X X
Adopt only those
sections that are
listed below		 X X X X X X
Chapter / Section
1240 X
1241 X
1242 X
1243 X
1250 X
1251 X
1252 X
1253 X
1254 X

The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.

12-2 2022 CALIFORNIA BUILDING CODE

Copyright © 2022 by, or licensed to, International Code Council, Inc. (ALL RIGHTS RESERVED); licensed to California Building Standards Commission pursuant to License Agreement. No further reproductions is authorized. Any unauthorized reproduction or distribution is a violation of the federal copyright act and the license agreement, and subject to civil and criminal penalties thereunder.

CHAPTER 12

INTERIOR ENVIRONMENT

User note:

About this chapter: Chapter 12 provides minimum provisions for the interior of buildings—the occupied environment. Ventilation, lighting, and space heating are directly regulated in this chapter and in conjunction with the California Mechanical Code and the California Energy Code . Minimum room size, maximum room-to-room sound transmission and classroom acoustics are set for educational occupancies.

installation of upper ventilators, installation more than 3 feet (914 mm) below the ridge or highest point of the space shall be permitted.

1202.2.2 Openings into attic. Exterior openings into the attic space of any building intended for human occupancy shall be protected to prevent the entry of birds, squirrels, rodents, snakes and other similar creatures. Openings for ventilation having a least dimension of not less than 1 /16 inch (1.6 mm) and not more than 1 /4 inch (6.4 mm) shall be permitted. Openings for ventilation having a least dimension larger than 1 /4 inch (6.4 mm) shall be provided with corrosion-resistant wire cloth screening, hardware cloth, perforated vinyl or similar material with openings having a least dimension of not less than 1 /16 inch (1.6 mm) and not more than 1 /4 inch (6.4 mm). Where combustion air is obtained from an attic area, it shall be in accordance with Chapter 7 of the California Mechanical Code .

1202.3 Unvented attic and unvented enclosed rafter assemblies.

assemblies. Unvented attics and unvented enclosed roof framing assemblies created by ceilings applied directly to the underside of the roof framing members/rafters and the structural roof sheathing at the top of the roof framing members shall be permitted where all of the following conditions are met:

  1. The unvented attic space is completely within the building thermal envelope.

  2. No interior Class I vapor retarders are installed on the ceiling side (attic floor) of the unvented attic assembly or on the ceiling side of the unvented enclosed roof framing assembly.

  3. Where wood shingles or shakes are used, not less than a 1/4-inch (6.4 mm) vented airspace separates the shingles or shakes and the roofing underlayment above the structural sheathing.

  4. In Climate Zones 5, 6, 7 and 8, any air-impermeable insulation shall be a Class II vapor retarder or shall have a Class II vapor retarder coating or covering in direct contact with the underside of the insulation.

4.1. [HCD 1 & HCD 2] In California Climate Zones 14 and 16, a Class I or Class II vapor retarder shall be installed on the indirectly conditioned space side of all insulation in an unvented attic with air-permeable insulation, for condensation control.

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▸Contents — California Building Code (Title 24, Part 2)
California Building Code (Title 24, Part 2)
  1. Chapter 2 — DEFINITIONS AND ABBREVIATIONS
  2. Appendix G — FLOOD-RESISTANT
  3. Appendix L — EARTHQUAKE RECORDING
  4. Appendix M — TSUNAMI-GENERATED
  5. Appendix N — REPLICABLE
  6. Appendix O — PERFORMANCE-BASED
  7. Chapter 1 — SCOPE AND ADMINISTRATION
  8. Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
  9. Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY A…
  10. Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
  11. Chapter 6 — TYPES OF CONSTRUCTION
  12. Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
  13. Chapter 7A — MATERIALS AND CONSTRUCTION
  14. Chapter 8 — INTERIOR FINISHES
  15. Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
  16. Chapter 10 — MEANS OF EGRESS
  17. Chapter 11A — HOUSING ACCESSIBILITY
  18. Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
  19. ▸Chapter 12 — INTERIOR ENVIRONMENT
    Overview
    1. Section 1201
    2. Section 1202
    3. Section 1203
    4. Section 1204
    5. Section 1205
    6. Section 1206
    7. Section 1207
    8. Section 1208
    9. Section 1209
    10. Section 1210
    11. Section 1211 — [HCD 1 & HCD 2]
    12. Section 1212 — [HCD 1]
    13. Section 1213
    14. Section 1214
    15. Section 1215
    16. Section 1216
    17. Section 1217
    18. Section 1218
    19. Section 1219
    20. Section 1220
    21. Section 1221
    22. Section 1222
    23. Section 1223
    24. Section 1224 — [OSHPD 1]
    25. Section 1225 — [OSHPD 2]
    26. Section 1226 — [OSHPD 3]
    27. Section 1227 — [OSHPD 4]
    28. Section 1228 — [OSHPD 5]
    29. Section 1229
    30. Section 1230 — [BSCC]
    31. Section 1231 — [BSCC]
    32. Section 1232
    33. Section 1233
    34. Section 1234
    35. Section 1235 — [DPH]
    36. Section 1236 — [DPH]
    37. Section 1237 — [DPH]
    38. Section 1238
    39. Section 1239
    40. Section 1240 — [AGR]
    41. Section 1241 — [AGR]
    42. Section 1242 — [AGR]
    43. Section 1243 — [AGR]
    44. Section 1244
    45. Section 1245
    46. Section 1246
    47. Section 1247
    48. Section 1248
    49. Section 1249
    50. Section 1250 — [CA]
    51. Section 1251 — [CA]
    52. Section 1252 — [CA]
    53. Section 1253 — [CA]
    54. Section 1254 — [CA]
  20. Chapter 14 — EXTERIOR WALLS
  21. Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
  22. Chapter 16 — STRUCTURAL DESIGN
  23. Chapter 16A — STRUCTURAL DESIGN
  24. Chapter 17 — SPECIAL INSPECTIONS AND TESTS
  25. Chapter 18 — SOILS AND FOUNDATIONS
  26. Chapter 19 — CONCRETE
  27. Chapter 20 — ALUMINUM
  28. Chapter 21 — MASONRY
  29. Chapter 22 — STEEL
  30. Chapter 23 — WOOD
  31. Chapter 24 — GLASS AND GLAZING
  32. Chapter 25 — GYPSUM BOARD, GYPSUM PANEL PRODUCTS AND PLASTER
  33. Chapter 26 — PLASTIC
  34. Chapter 27 — ELECTRICAL
  35. Chapter 28 — MECHANICAL SYSTEMS
  36. Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
  37. Chapter 31 — SPECIAL CONSTRUCTION
  38. Chapter 31B — PUBLIC POOLS
  39. Chapter 31C — RADIATION
  40. Chapter 31D — FOOD ESTABLISHMENTS
  41. Chapter 31F — MARINE OIL TERMINALS
  42. Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
  43. Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
  44. Chapter 35 — REFERENCED STANDARDS
  45. Appendix A — EMPLOYEE QUALIFICATIONS
  46. Appendix B — BOARD OF APPEALS
  47. Appendix C — GROUP U – AGRICULTURAL BUILDINGS
  48. Appendix D — FIRE DISTRICTS
  49. Appendix F — RODENTPROOFING
  50. Appendix H — SIGNS
  51. Appendix I — PATIO COVERS
  52. Appendix J — GRADING
  53. Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES
  54. Appendix P — EMERGENCY HOUSING

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