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Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMMODATIONS, COMMERCIAL BUILDINGS AND PUBLIC HOUSING

Section 11B-504 — STAIRWAYS

2025 California Building Code (Title 24, Part 2) · 2025 edition · updated 2026-07-29 · California

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

11B- 504.1 General. Stairs shall comply with Section 11B- 504 .

11B- 504.2 Treads and risers. All steps on a flight of stairs shall have uniform riser heights and uniform tread depths. Risers shall be 4 inches ( 102 mm) high minimum and 7 inches ( 178 mm) high maximum. Treads shall be 11 inches ( 279 mm) deep minimum.

Exception: Curved stairways with winder treads are permitted at stairs which are not part of a required means of egress.

11B- 504.3 Open risers. Open risers are not permitted.

Exceptions: 1. On exterior stairways, an opening of not more than [1] / 2 inch (12.7 mm) may be permitted between the base of the riser and the tread.

2. On exterior stairways, risers constructed of grating containing openings of not more than [1] / 2 inch (12.7 mm) may be permitted.

11B- 504.4 Tread surface. Stair treads shall comply with Section 11B- 302. Changes in level, slopes exceeding 1:48, and detectable warnings shall not be permitted.

Exception: Reserved.

11B-504.4.1 Contrasting stripe. Interior stairs shall have the upper approach and lower tread marked by a stripe providing clear visual contrast. Exterior stairs shall have the upper approach and all treads marked by a stripe providing clear visual contrast.

The stripe shall be a minimum of 2 inches (51 mm) wide to a maximum of 4 inches (102 mm) wide placed parallel to, and not more than 1 inch (25 mm) from, the nose of the step or upper approach. The stripe shall extend the full width of the step or upper approach and shall be of material that is at least as slip resistant as the other treads of the stair. A painted stripe shall be acceptable. Grooves shall not be used to satisfy this requirement.

11B- 504.5 Nosings. The radius of curvature at the leading edge of the tread shall be [1] / 2 inch ( 12.7 mm) maximum. Nosings that project beyond risers shall have the underside of the leading edge curved or beveled. Risers shall be permitted to slope under the tread at an angle of 30 degrees maximum from vertical. The permitted projection of the nosing shall extend 1 [1] / 4 inches (32 mm) maximum over the tread below.

Exception: In existing buildings there is no requirement to retroactively alter existing nosing projections of 1 [1] / 2 inches (38 mm) which were constructed in compliance with the building code in effect at the time of original construction.

FIGURE 11B -504.5—STAIR NOSINGS

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMMODATIONS, COMMERCIAL BUILDINGS AND PUBLIC HOUSING

11B- 504.6 Handrails. Stairs shall have handrails complying with Section 11B- 505 .

11B- 504.7 Wet conditions. Stair treads and landings subject to wet conditions shall be designed to prevent the accumulation of water.

11B-504.8 Floor identification. Floor identification signs required by Chapter 10, Section 1023.9 complying with Sections 11B-703.1, 11B-703.2, 11B-703.3 and 11B-703.5 shall be located at the landing of each floor level, placed adjacent to the door on the latch side, in all enclosed stairways in buildings two or more stories in height to identify the floor level. At the exit discharge level, the sign shall include a raised five pointed star located to the left of the identifying floor level. The outside diameter of the star shall be the same as the height of the raised characters.

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▸ Contents — 2025 California Building Code (Title 24, Part 2)
2025 California Building Code (Title 24, Part 2)
  1. Chapter 1 — ADMINISTRATION
  2. Chapter 2 — DEFINITIONS
  3. Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
  4. Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY A…
  5. Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
  6. Chapter 6 — TYPES OF CONSTRUCTION
  7. Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
  8. Chapter 7A — MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR W…
  9. Chapter 8 — INTERIOR FINISHES
  10. Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
  11. Chapter 10 — MEANS OF EGRESS
  12. Chapter 11 — RESERVED
  13. Chapter 11A — HOUSING ACCESSIBILITY
  14. ▸ Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
    Overview
    1. Section 11B-101 — PURPOSE
    2. Section 11B-104 — CONVENTIONS
    3. Section 11B-105 — REFERENCED STANDARDS
    4. Section 11B-106 — DEFINITIONS
    5. Section 11B-201 — APPLICATION
    6. Section 11B-202 — EXISTING BUILDINGS AND FACILITIES
    7. Section 11B-203 — GENERAL EXCEPTIONS
    8. Section 11B-204 — PROTRUDING OBJECTS
    9. Section 11B-205 — OPERABLE PARTS
    10. Section 11B-206 — ACCESSIBLE ROUTES
    11. Section 11B-207 — ACCESSIBLE MEANS OF EGRESS
    12. Section 11B-208 — PARKING SPACES
    13. Section 11B-209 — PASSENGER DROP-OFF AND LOADING ZONES AND BUS…
    14. Section 11B-210 — STAIRWAYS
    15. Section 11B-211 — DRINKING FOUNTAINS AND BOTTLE-FILLING STATIONS
    16. Section 11B-212 — KITCHENS, KITCHENETTES, WET BARS AND SINKS
    17. Section 11B-213 — TOILET FACILITIES AND BATHING FACILITIES
    18. Section 11B-214 — WASHING MACHINES AND CLOTHES DRYERS
    19. Section 11B-215 — FIRE ALARM SYSTEMS AND CARBON MONOXIDE ALARM…
    20. Section 11B-216 — SIGNS
    21. Section 11B-217 — TELEPHONES
    22. Section 11B-218 — TRANSPORTATION FACILITIES
    23. Section 11B-219 — ASSISTIVE LISTENING SYSTEMS
    24. Section 11B-220 — AUTOMATIC TELLER MACHINES, FARE MACHINES AND…
    25. Section 11B-221 — ASSEMBLY AREAS
    26. Section 11B-222 — DRESSING, FITTING AND LOCKER ROOMS
    27. Section 11B-223 — MEDICAL CARE AND LONG-TERM CARE FACILITIES
    28. Section 11B-224 — TRANSIENT LODGING GUEST ROOMS, HOUSING
    29. Section 11B-225 — STORAGE
    30. Section 11B-226 — DINING SURFACES AND WORK SURFACES
    31. Section 11B-227 — SALES AND SERVICE
    32. Section 11B-228 — DEPOSITORIES, VENDING MACHINES, CHANGE MACHI…
    33. Section 11B-229 — WINDOWS
    34. Section 11B-230 — TWO-WAY COMMUNICATION SYSTEMS
    35. Section 11B-231 — JUDICIAL FACILITIES
    36. Section 11B-232 — DETENTION FACILITIES AND CORRECTIONAL FACILI…
    37. Section 11B-233 — PUBLIC HOUSING FACILITIES
    38. Section 11B-234 — AMUSEMENT RIDES
    39. Section 11B-235 — RECREATIONAL BOATING FACILITIES
    40. Section 11B-236 — EXERCISE MACHINES AND EQUIPMENT
    41. Section 11B-237 — FISHING PIERS AND PLATFORMS
    42. Section 11B-238 — GOLF FACILITIES
    43. Section 11B-239 — MINIATURE GOLF FACILITIES
    44. Section 11B-240 — PLAY AREAS
    45. Section 11B-241 — SAUNAS AND STEAM ROOMS
    46. Section 11B-242 — SWIMMING POOLS, WADING POOLS AND SPAS
    47. Section 11B-243 — SHOOTING FACILITIES WITH FIRING POSITIONS
    48. Section 11B-244 — RELIGIOUS FACILITIES
    49. Section 11B-245 — PUBLIC ACCOMMODATIONS LOCATED IN PRIVATE RES…
    50. Section 11B-246 — OUTDOOR DEVELOPED AREAS
    51. Section 11B-247 — DETECTABLE WARNINGS AND DETECTABLE DIRECTION…
    52. Section 11B-248 — COMMON USE AREAS AND EMPLOYEE WORK AREAS
    53. Section 11B-249 — ADULT CHANGING FACILITIES
    54. Section 11B-250 — CIRCULATION PATHS
    55. Section 11B-301 — GENERAL
    56. Section 11B-302 — FLOOR OR GROUND SURFACES
    57. Section 11B-303 — CHANGES IN LEVEL
    58. Section 11B-304 — TURNING SPACE
    59. Section 11B-305 — CLEAR FLOOR OR GROUND SPACE
    60. Section 11B-306 — KNEE AND TOE CLEARANCE
    61. Section 11B-307 — PROTRUDING OBJECTS
    62. Section 11B-308 — REACH RANGES
    63. Section 11B-309 — OPERABLE PARTS
    64. Section 11B-401 — GENERAL
    65. Section 11B-402 — ACCESSIBLE ROUTES
    66. Section 11B-403 — W ALKING SURFACES
    67. Section 11B-404 — DOORS, DOORWAYS AND GATES
    68. Section 11B-405 — RAMPS
    69. Section 11B-406 — CURB RAMPS, BLENDED TRANSITIONS AND ISLANDS
    70. Section 11B-407 — ELEVATORS
    71. Section 11B-408 — LIMITED-USE/LIMITED-APPLICATION ELEVATORS
    72. Section 11B-409 — PRIVATE RESIDENCE ELEVATORS
    73. Section 11B-410 — PLATFORM LIFTS
    74. Section 11B-411 — DESTINATION-ORIENTED ELEVATORS
    75. Section 11B-501 — GENERAL
    76. Section 11B-502 — PARKING SPACES
    77. Section 11B-503 — PASSENGER DROP-OFF AND LOADING ZONES
    78. Section 11B-504 — STAIRWAYS
    79. Section 11B-505 — HANDRAILS
    80. Section 11B-601 — GENERAL
    81. Section 11B-602 — DRINKING FOUNTAINS AND BOTTLE-FILLING STATIONS
    82. Section 11B-603 — TOILET AND BATHING ROOMS
    83. Section 11B-604 — WATER CLOSETS AND TOILET COMPARTMENTS
    84. Section 11B-605 — URINALS
    85. Section 11B-606 — LAVATORIES AND SINKS
    86. Section 11B-607 — BATHTUBS
    87. Section 11B-608 — SHOWER COMPARTMENTS
    88. Section 11B-609 — GRAB BARS
    89. Section 11B-610 — SEATS
    90. Section 11B-611 — WASHING MACHINES AND CLOTHES DRYERS
    91. Section 11B-612 — SAUNAS AND STEAM ROOMS
    92. Section 11B-701 — GENERAL
    93. Section 11B-702 — FIRE ALARM SYSTEMS
    94. Section 11B-703 — SIGNS
    95. Section 11B-704 — TELEPHONES
    96. Section 11B-705 — DETECTABLE WARNINGS AND DETECTABLE DIRECTION…
    97. Section 11B-706 — ASSISTIVE LISTENING SYSTEMS
    98. Section 11B-707 — AUTOMATIC TELLER MACHINES, FARE MACHINES AND…
    99. Section 11B-708 — TWO-WAY COMMUNICATION SYSTEMS
    100. Section 11B-801 — GENERAL
    101. Section 11B-802 — WHEELCHAIR SPACES, COMPANION SEATS AND DESIG…
    102. Section 11B-803 — DRESSING, FITTING AND LOCKER ROOMS
    103. Section 11B-804 — KITCHENS, KITCHENETTES AND WET BARS
    104. Section 11B-805 — MEDICAL CARE AND LONG-TERM CARE FACILITIES
    105. Section 11B-806 — TRANSIENT LODGING GUEST ROOMS
    106. Section 11B-807 — HOLDING CELLS AND HOUSING CELLS
    107. Section 11B-808 — COURTROOMS
    108. Section 11B-809 — RESIDENTIAL DWELLING UNITS
    109. Section 11B-810 — TRANSPORTATION FACILITIES
    110. Section 11B-811 — STORAGE
    111. Section 11B-812 — ELECTRIC VEHICLE CHARGING STATIONS
    112. Section 11B-813 — ADULT CHANGING FACILITIES
    113. Section 11B-901 — GENERAL
    114. Section 11B-902 — DINING SURFACES AND WORK SURFACES
    115. Section 11B-903 — BENCHES
    116. Section 11B-904 — CHECK-OUT AISLES AND SALES AND SERVICE COUNT…
    117. Section 11B-1001 — GENERAL
    118. Section 11B-1002 — AMUSEMENT RIDES
    119. Section 11B-1003 — RECREATIONAL BOATING FACILITIES
    120. Section 11B-1004 — EXERCISE MACHINES AND EQUIPMENT
    121. Section 11B-1005 — FISHING PIERS AND PLATFORMS
    122. Section 11B-1006 — GOLF FACILITIES
    123. Section 11B-1007 — MINIATURE GOLF FACILITIES
    124. Section 11B-1008 — PLAY AREAS
    125. Section 11B-1009 — SWIMMING POOLS, WADING POOLS AND SPAS
    126. Section 11B-1010 — SHOOTING FACILITIES WITH FIRING POSITIONS
  15. Chapter 12 — INTERIOR ENVIRONMENT
  16. Chapter 13 — ENERGY EFFICIENCY
  17. Chapter 14 — EXTERIOR WALLS
  18. Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
  19. Chapter 16 — STRUCTURAL DESIGN
  20. Chapter 16A — STRUCTURAL DESIGN
  21. Chapter 17 — SPECIAL INSPECTIONS AND TESTS
  22. Chapter 17A — SPECIAL INSPECTIONS AND TESTS
  23. Chapter 18 — SOILS AND FOUNDATIONS
  24. Chapter 18A — SOILS AND FOUNDATIONS
  25. Chapter 19 — CONCRETE
  26. Chapter 19A — CONCRETE
  27. Chapter 20 — ALUMINUM
  28. Chapter 21 — MASONRY
  29. Chapter 21A — MASONRY
  30. Chapter 22 — STEEL
  31. Chapter 22A — STEEL
  32. Chapter 23 — WOOD
  33. Chapter 24 — GLASS AND GLAZING
  34. Chapter 25 — GYPSUM PANEL PRODUCTS AND PLASTER
  35. Chapter 26 — PLASTIC
  36. Chapter 27 — ELECTRICAL
  37. Chapter 28 — MECHANICAL SYSTEMS
  38. Chapter 29 — PLUMBING SYSTEMS
  39. Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
  40. Chapter 31 — SPECIAL CONSTRUCTION
  41. Chapter 31A — SYSTEMS FOR WINDOW CLEANING OR EXTERIOR BUILDING…
  42. Chapter 31B — PUBLIC POOLS
  43. Chapter 31C — RADIATION
  44. Chapter 31D — FOOD ESTABLISHMENTS
  45. Chapter 31F — MARINE OIL TERMINALS
  46. Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
  47. Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
  48. Chapter 34 — RESERVED
  49. Chapter 35 — REFERENCED STANDARDS
  50. Appendix A — EMPLOYEE QUALIFICATIONS
  51. Appendix B — BOARD OF APPEALS
  52. Appendix C — GROUP U—AGRICULTURAL BUILDINGS
  53. Appendix D — FIRE DISTRICTS
  54. Appendix E — RESERVED
  55. Appendix F — RODENTPROOFING
  56. Appendix G — FLOOD-RESISTANT CONSTRUCTION
  57. Appendix H — SIGNS
  58. Appendix I — PATIO COVERS
  59. Appendix J — GRADING
  60. Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES PROTECTED B…
  61. Appendix L — EARTHQUAKE RECORDING INSTRUMENTATION
  62. Appendix M — TSUNAMI-GENERATED FLOOD HAZARDS
  63. Appendix N — REPLICABLE BUILDINGS
  64. Appendix O — PERFORMANCE-BASED APPLICATION
  65. Appendix P — SLEEPING LOFTS
  66. Appendix Q — EMERGENCY HOUSING

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