CBC · California Building Code
Curb ramps, blended transitions and allowable changes in level
If your sidewalk crosses a street, CBC requires a curb ramp or blended transition sized and sloped for accessibility (typical ramp slope max 1:12, blended max 1:20), with 48‑inch clear widths/landings, 36‑inch detectable warnings, and strict rules for small changes in level (vertical ≤1/4 in allowed, 1/4–1/2 in beveled at ≤1:2, >1/2 in must be ramped) — see § 11B-406, § 11B-303 and § 11B-206.2.19.
Last reviewed: July 5, 2026
What the code requires — 2-4 sentences
When a pedestrian route crosses a curb at a street crossing the CBC requires a curb ramp, blended transition, or a combination that meets the curb‑ramp requirements in Division 4, Section 11B-406. Pedestrian changes in level are tightly limited: vertical changes up to 1/4 in permitted, 1/4–1/2 in must be beveled (max 1:2), and greater than 1/2 in must be ramped in accordance with 11B-405 or 11B-406 (§ 11B-206.2.19; § 11B-303). These dimensional, slope, landing and detectable‑warning provisions are set out in § 11B-406 and the related changes‑in‑level rules in § 11B-303.
Requirements in detail
Which element to provide
- Pedestrian street crossings with walks/sidewalks must be connected by a curb ramp, blended transition, or combination complying with Section 11B-406; the curb ramp or blended transition (excluding flared sides) must lie wholly within the width of the crossing (§ 11B-206.2.19).
Running slope and segment limits
- Perpendicular and parallel curb ramp runs: maximum running slope 1:12 (§ 11B-406.2.1; § 11B-406.3.1).
- Blended transitions: maximum running slope 1:20 (§ 11B-406.4.1).
Cross slope, counter slope, flared sides
- Maximum cross slope of curb ramps and blended transitions: 1:48 (§ 11B-406.5.7).
- Counter slopes of adjoining gutters/road surfaces within 24 in of the ramp must not be steeper than 1:20; adjacent surfaces at transitions shall be level with the ramp top/bottom (§ 11B-406.5.8).
- Flared sides (where pedestrians cross the flare) shall not be steeper than 1:10 (§ 11B-406.2.2 and commentary).
Widths, landings and turning spaces
- Minimum clear width of curb ramp runs (excluding flares), blended transitions and turning spaces: 48 inches (1219 mm) (§ 11B-406.5.2).
- Landings at the top of curb ramps/blended transitions: clear length 48 inches (1219 mm) minimum, width at least as wide as the ramp run, and slope in all directions limited to 1:48 (§ 11B-406.5.3). Parallel ramps are excepted from this landing requirement (§ 11B-406.5.3 exception).
- Turning space at the bottom of parallel curb ramps: 48 in × 48 in (1219 × 1219 mm) minimum; slope 1:48 maximum in all directions (§ 11B-406.3.2).
Detectable warnings
- Detectable warnings are required on curb ramps and blended transitions and must comply with Chapter 11B‑705; for curb ramps they extend 36 in (914 mm) in direction of travel and across the full ramp width less up to 2 in on each side; blended transitions require 36 in depth as well (§ 11B-406.5.12; § 11B-705.1.2.2.1; § 11B-705.1.2.5).
Grade breaks and alignment
- Grade breaks at the top and bottom of ramp runs must be perpendicular to the direction of travel; grade breaks are not permitted on ramp run surfaces or turning spaces (surfaces that meet at grade breaks must be flush) (§ 11B-406.5.6).
Changes in level (summary of § 11B-303)
- 0–1/4 in (6.4 mm): vertical change is permitted without edge treatment (§ 11B-303.2).
- Over 1/4 in up to 1/2 in (6.4–12.7 mm): must be beveled with slope no steeper than 1:2 (§ 11B-303.3).
- Greater than 1/2 in (12.7 mm): must be ramped and comply with § 11B-405 (ramps) or § 11B-406 (curb ramps) (§ 11B-303.4).
- Abrupt vertical differences exceeding 4 in must be identified by warning curbs at least 6 in high, with limited exceptions (§ 11B-303.5).
Decision‑relevant dimensions (quick reference table)
| Item | Required value | Where to use it | Code Reference |
|---|---|---|---|
| Max running slope — perpendicular / parallel ramps | 1:12 (8.33%) | Ramp runs (§ 11B-406.2.1, § 11B-406.3.1) | § 11B-406.2.1 / § 11B-406.3.1 |
| Max running slope — blended transition | 1:20 (5%) | Blended transitions (§ 11B-406.4.1) | § 11B-406.4.1 |
| Max cross slope | 1:48 (~2.08%) | Ramp and blended transition surface (§ 11B-406.5.7) | § 11B-406.5.7 |
| Max counter slope (within 24 in) | 1:20 (5%) | Gutter/road adjacent to ramp (§ 11B-406.5.8) | § 11B-406.5.8 |
| Minimum clear width | 48 in (1219 mm) | Ramp runs, blended transitions, turning spaces (§ 11B-406.5.2) | § 11B-406.5.2 |
| Landing size | 48 in long × ≥ramp width; slope ≤1:48 | Top of ramp/blended transition (§ 11B-406.5.3) | § 11B-406.5.3 |
| Turning space (parallel ramps) | 48 in × 48 in (1219 × 1219 mm) | Bottom of parallel curb ramp (§ 11B-406.3.2) | § 11B-406.3.2 |
| Flared sides max slope | 1:10 (10%) | When pedestrians cross flared sides (§ 11B-406.2.2) | § 11B-406.2.2 |
| Detectable warning depth | 36 in (914 mm) | Perpendicular ramps, blended transitions (§ 11B-705.1.2.2.1; § 11B-705.1.2.5) | § 11B-705.1.2.2.1 / § 11B-705.1.2.5 |
| Vertical change allowed without treatment | 0–1/4 in (≤6.4 mm) | Floor/ground surfaces (§ 11B-303.2) | § 11B-303.2 |
| Beveled change allowed | >1/4 to 1/2 in; bevel max 1:2 | Floor/ground surfaces (§ 11B-303.3) | § 11B-303.3 |
| Change requiring ramping | >1/2 in | Must comply with § 11B-405 or § 11B-406 (§ 11B-303.4) | § 11B-303.4 |
(Each numeric entry above is sourced to the cited CBC section.)
Exceptions & special cases
- Parallel curb ramps are not required to provide the 48 in landing at the top as specified in § 11B-406.5.3 (parallel ramp exception).
- Diagonal (corner) curb ramps have special clear‑space and marking placement rules: the bottom must provide a 48 in clear space outside active traffic lanes or within crossing markings; corner ramps with flared sides must include a 24 in straight curb segment on each side within the marked crossing (§ 11B-406.5.9; § 11B-406.5.10).
- The obligation in § 11B-206.2.19 to provide curb ramps/blended transitions does not apply where the appropriate administrative authority prohibits pedestrian crossings at that location (exception in § 11B-206.2.19).
- Detectable warning exceptions exist for some existing installations and limited replacement; see Chapter 11B‑705 for permitted in‑kind replacements and alternate contrast rules (§ 11B-705 exceptions).
Common mistakes
- Designing ramp runs steeper than 1:12 (or blended transitions steeper than 1:20) or allowing cross slopes greater than 1:48 — slope checks are the most frequent noncompliance. See § 11B-406.2.1, § 11B-406.4.1, § 11B-406.5.7.
- Forgetting the required 48 in landing (or using a landing with slope >1:48) at the top of ramps (unless a permitted exception like parallel ramps applies) (§ 11B-406.5.3).
- Placing detectable warnings incorrectly (wrong depth, not full ramp width less allowances, or wrong offset from curb face) — follow § 11B-705 dimensions precisely.
- Allowing grade breaks that are not perpendicular to ramp runs or allowing grade breaks on ramp surfaces/turning spaces (§ 11B-406.5.6).
- Treating changes >1/2 in as mere bevels instead of full ramps; any change >1/2 in must be ramped per § 11B-303.4.
Worked example — designing a perpendicular curb ramp for a 6‑inch curb
Situation: existing curb height = 6 in (152 mm). You are designing a perpendicular curb ramp where pedestrians will walk across the ramp and flared sides are required.
- Running slope limit: maximum 1:12. Required ramp run length = rise × 12 = 6 in × 12 = 72 in (6 ft). Verify available horizontal distance in the street gutter to accommodate 72 in without encroaching prohibited traffic elements (§ 11B-406.2.1).
- Flared sides: because pedestrians will cross flared sides, max flare slope = 1:10. Design the flared side widths and slopes so they meet this limit (§ 11B-406.2.2).
- Landing at top: provide a landing 48 in deep across the full ramp width (excluding flares). Landing slope in any direction must be ≤1:48. If the ramp run clear width is 48 in, top landing must be 48 in (length) × 48 in (width), slope ≤1:48 (§ 11B-406.5.3).
- Cross slope: ensure ramp surface cross slope ≤1:48 (to prevent side drainage/tilting) (§ 11B-406.5.7).
- Detectable warning: install a 36 in deep detectable warning extending full ramp width less up to 2 in on each side; position the near edge of the detectable warning 6–8 in from the demarcation line at the face of the curb per the detectable‑warning rules (§ 11B-705.1.2.2.1).
- Counter slope: check gutter/road within 24 in of the ramp top and bottom so it's no steeper than 1:20 (if it is steeper, revise approach geometry) (§ 11B-406.5.8).
If any site dimension cannot fit these numbers (for example, less than 72 in available run), you must either reconfigure the crossing (use parallel or diagonal ramp geometry) or provide alternative accommodation and document technical infeasibility; do not exceed the slope limits. (§ 11B-406 and associated ramp provisions in § 11B-405).
Related provisions
- § 11B-405 — Ramps (design rules when changes in level are greater than 1/2 in).
- § 11B-705 — Detectable warnings (dimensions, color, contrast, location).
- § 11B-303 — Changes in level (vertical, beveled, ramping thresholds).
- § 11B-206.2.19 — Pedestrian street crossings requirement to provide curb ramps/blended transitions at crossings.
- § 11B-405.10 / § 11B-405.4 — Finish, wet‑condition and surface requirements that apply to ramp and landing surfaces (slip resistance, water drainage).
Code references
Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:
CBC § 11B-406.5.5 High relevance — show source text
11B-406.5.5 Wet conditions. Curb ramps and blended transitions shall comply with Section 11B-405.10.
2025 CALIFORNIA BUILDING CODE 11B-59
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMMODATIONS, COMMERCIAL BUILDINGS AND PUBLIC HOUSING
11B-406.5.6 Grade breaks. Grade breaks at the top and bottom of curb ramp runs shall be perpendicular to the direction of the ramp run. Grade breaks shall not be permitted on the surface of ramp runs and turning spaces. Surface slopes that meet at grade breaks shall be flush.
11B-406.5.7 Cross slope. The cross slope of curb ramps and blended transitions shall be 1:48 maximum.
11B-406.5.8 Counter slope. Counter slopes of adjoining gutters and road surfaces immediately adjacent to and within 24 inches (610 mm) of the curb ramp shall not be steeper than 1:20. The adjacent surfaces at transitions at curb ramps to walks, gutters and streets shall be at the same level.
FIGURE 11B-406.5.8 —COUNTER SLOPE OF SURFACES ADJACENT TO CURB RAMPS
11B-406.5.9 Clear space at diagonal curb ramps. The bottom of diagonal curb ramps shall have a clear space 48 inches (1219 mm) minimum outside active traffic lanes of the roadway. Diagonal curb ramps provided at marked crossings shall provide the 48 inches (1219 mm) minimum clear space within the markings.
11B-406.5.10 Diagonal curb ramps. Diagonal or corner type curb ramps are perpendicular or parallel curb ramps that are oriented diagonally at an intersection. Diagonal or corner type curb ramps with returned curbs or other well-defined edges shall have the edges parallel to the direction of pedestrian flow. Diagonal curb ramps with flared sides shall have a segment of curb 24 inches (610 mm) long minimum located on each side of the curb ramp and within the marked crossing.
FIGURE 11B -406.5.10—DIAGONAL OR CORNER TYPE CURB RAMPS
11B-406.5.11 Reserved.
11B-406.5.12 Detectable warnings. Curb ramps and blended transitions shall have detectable warnings complying with Section 11B-705.
11B-406.6 Islands. Raised islands in crossings shall be cut through level with the street or have curb ramps at both sides. The clear width of the accessible route at islands shall be 60 inches (1524 mm) wide minimum. Where curb ramps are provided, they shall comply with Section 11B-406. Landings complying with Section 11B-406.5.3 and the accessible route shall be permitted to overlap. Islands shall have detectable warnings complying with Section 11B-705.
FIGURE 11B-406.6—ISLANDS IN CROSSINGS
11B-60 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMMODATIONS, COMMERCIAL BUILDINGS AND PUBLIC HOUSING
CBC § 405.9.2 High relevance — show source text
FIGURE 11B -405.9.2—CURB OR BARRIER EDGE PROTECTION
11B- 405.10 Wet conditions. Landings subject to wet conditions shall be designed to prevent the accumulation of water.
SECTION 11B- 406 — CURB RAMPS, BLENDED TRANSITIONS AND ISLANDS
11B-406.1 General. Curb ramps, blended transitions and islands on accessible routes shall comply with Section 11B-406. Curb ramps may be perpendicular, parallel, or a combination of perpendicular and parallel.
11B-406.1.1 Perpendicular curb ramps. Perpendicular curb ramps shall comply with Section 11B-406.2.
11B-406.1.2 Parallel curb ramps. Parallel curb ramps shall comply with Section 11B-406.3.
11B-406.1.3 Blended transitions. Blended transitions shall comply with Section 11B-406.4.
11B-406.1.4 Islands. Islands shall comply with Section 11B-406.6.
11B-406.2 Perpendicular curb ramps. Perpendicular curb ramps shall comply with Sections 11B-406.2 and 11B-406.5.
11B-406.2.1 Slope. Ramp runs shall have a running slope not steeper than 1:12.
11B-406.2.2 Sides of curb ramps. Where provided, curb ramp flares shall not be steeper than 1:10.
11B-58 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMMODATIONS, COMMERCIAL BUILDINGS AND PUBLIC HOUSING
FIGURE 11B-406.2.2—SIDES OF CURB RAMPS
11B-406.3 Parallel curb ramps. Parallel curb ramps shall comply with Sections 11B-406.3 and 11B-406.5. A parallel curb ramp may be provided with one sloping segment or two opposing sloping segments.
11B-406.3.1 Slope. The running slope of the curb ramp segments shall be in-line with the direction of sidewalk travel. Ramp runs shall have a running slope not steeper than 1:12.
11B-406.3.2 Turning space. A turning space 48 inches (1219 mm) minimum by 48 inches (1219 mm) minimum shall be provided at the bottom of the curb ramp. The slope of the turning space in all directions shall be 1:48 maximum.
FIGURE 11B-406.3.2—PARALLEL CURB RAMPS
Col1 Col2 Col3 48 min Col5 Col6 48 min
121948 min
12191219 1219 1219 11B-406.4 Blended transitions. Blended transitions shall comply with Sections 11B-406.4 and 11B-406.5.
CBC § 11B-406.2.2 High relevance — show source text
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMMODATIONS, COMMERCIAL BUILDINGS AND PUBLIC HOUSING
FIGURE 11B-406.2.2—SIDES OF CURB RAMPS
11B-406.3 Parallel curb ramps. Parallel curb ramps shall comply with Sections 11B-406.3 and 11B-406.5. A parallel curb ramp may be provided with one sloping segment or two opposing sloping segments.
11B-406.3.1 Slope. The running slope of the curb ramp segments shall be in-line with the direction of sidewalk travel. Ramp runs shall have a running slope not steeper than 1:12.
11B-406.3.2 Turning space. A turning space 48 inches (1219 mm) minimum by 48 inches (1219 mm) minimum shall be provided at the bottom of the curb ramp. The slope of the turning space in all directions shall be 1:48 maximum.
FIGURE 11B-406.3.2—PARALLEL CURB RAMPS
Col1 Col2 Col3 48 min Col5 Col6 48 min
121948 min
12191219 1219 1219 11B-406.4 Blended transitions. Blended transitions shall comply with Sections 11B-406.4 and 11B-406.5.
11B-406.4.1 Slope. Blended transitions shall have a running slope not steeper than 1:20.
11B-406.5 Common requirements. Curb ramps and blended transitions shall comply with Section 11B-406.5.
11B-406.5.1 Location. Curb ramps and the flared sides of curb ramps shall be located so that they do not project into vehicular traffic lanes, parking spaces or parking access aisles. Curb ramps at marked crossings shall be wholly contained within the markings, excluding any flared sides.
Exception: Diagonal curb ramps shall comply with Section 11B-406.5.9.
11B-406.5.2 Width. The clear width of curb ramp runs (excluding any flared sides), blended transitions, and turning spaces shall be 48 inches (1219 mm) minimum.
11B-406.5.3 Landings. Landings shall be provided at the tops of curb ramps and blended transitions. The landing clear length shall be 48 inches (1219 mm) minimum. The landing clear width shall be at least as wide as the curb ramp, excluding any flared sides, or the blended transition leading to the landing. The slope of the landing in all directions shall be 1:48 maximum.
Exception: Parallel curb ramps shall not be required to comply with Section 11B-406.5.3.
FIGURE 11B- 406.5.3—LANDINGS AT THE TOP OF CURB RAMPS
11B-406.5.4 Floor or ground surfaces. Floor or ground surfaces of curb ramps and blended transitions shall comply with Section 11B-405.4.
CBC § 11B-406.5 High relevance — show source text
11B-406.5 Common requirements. Curb ramps and blended transitions shall comply with Section 11B-406.5.
11B-406.5.1 Location. Curb ramps and the flared sides of curb ramps shall be located so that they do not project into vehicular traffic lanes, parking spaces or parking access aisles. Curb ramps at marked crossings shall be wholly contained within the markings, excluding any flared sides.
Exception: Diagonal curb ramps shall comply with Section 11B-406.5.9.
11B-406.5.2 Width. The clear width of curb ramp runs (excluding any flared sides), blended transitions, and turning spaces shall be 48 inches (1219 mm) minimum.
11B-406.5.3 Landings. Landings shall be provided at the tops of curb ramps and blended transitions. The landing clear length shall be 48 inches (1219 mm) minimum. The landing clear width shall be at least as wide as the curb ramp, excluding any flared sides, or the blended transition leading to the landing. The slope of the landing in all directions shall be 1:48 maximum.
Exception: Parallel curb ramps shall not be required to comply with Section 11B-406.5.3.
FIGURE 11B- 406.5.3—LANDINGS AT THE TOP OF CURB RAMPS
11B-406.5.4 Floor or ground surfaces. Floor or ground surfaces of curb ramps and blended transitions shall comply with Section 11B-405.4.
11B-406.5.5 Wet conditions. Curb ramps and blended transitions shall comply with Section 11B-405.10.
2025 CALIFORNIA BUILDING CODE 11B-59
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMMODATIONS, COMMERCIAL BUILDINGS AND PUBLIC HOUSING
11B-406.5.6 Grade breaks. Grade breaks at the top and bottom of curb ramp runs shall be perpendicular to the direction of the ramp run. Grade breaks shall not be permitted on the surface of ramp runs and turning spaces. Surface slopes that meet at grade breaks shall be flush.
11B-406.5.7 Cross slope. The cross slope of curb ramps and blended transitions shall be 1:48 maximum.
11B-406.5.8 Counter slope. Counter slopes of adjoining gutters and road surfaces immediately adjacent to and within 24 inches (610 mm) of the curb ramp shall not be steeper than 1:20. The adjacent surfaces at transitions at curb ramps to walks, gutters and streets shall be at the same level.
FIGURE 11B-406.5.8 —COUNTER SLOPE OF SURFACES ADJACENT TO CURB RAMPS
11B-406.5.9 Clear space at diagonal curb ramps. The bottom of diagonal curb ramps shall have a clear space 48 inches (1219 mm) minimum outside active traffic lanes of the roadway. Diagonal curb ramps provided at marked crossings shall provide the 48 inches (1219 mm) minimum clear space within the markings.
CBC § 405.8 High relevance — show source text
11B- 405.8 Handrails. Ramp runs shall have handrails complying with Section 11B- 505 .
Exceptions:
1. Reserved.
2. Reserved.
3. Curb ramps do not require handrails. 4. At door landings, handrails are not required on ramp runs less than 6 inches (152 mm) in rise or 72 inches (1829 mm) in length.
11B- 405.9 Edge protection. Edge protection complying with Section 11B- 405.9.2 shall be provided on each side of ramp runs and at each side of ramp landings.
Exceptions:
Edge protection shall not be required on ramps that are not required to have handrails and have sides complying with Section 11B- 406.2.2.
Edge protection shall not be required on the sides of ramp landings serving an adjoining ramp run or stairway.
Edge protection shall not be required on the sides of ramp landings having a vertical drop-off of [1] / 2 inch ( 12.7 mm) maximum within 10 inches ( 254 mm) horizontally of the minimum landing area specified in Section 11B- 405.7.
11B- 405.9.1 Reserved.
11B- 405.9.2 Curb or barrier. A curb or barrier shall be provided that prevents the passage of a 4-inch ( 102 mm) diameter sphere, where any portion of the sphere is within 4 inches ( 102 mm) of the finish floor or ground surface. To prevent wheel entrapment, the curb or barrier shall provide a continuous and uninterrupted barrier along the length of the ramp.
FIGURE 11B -405.9.2—CURB OR BARRIER EDGE PROTECTION
11B- 405.10 Wet conditions. Landings subject to wet conditions shall be designed to prevent the accumulation of water.
SECTION 11B- 406 — CURB RAMPS, BLENDED TRANSITIONS AND ISLANDS
11B-406.1 General. Curb ramps, blended transitions and islands on accessible routes shall comply with Section 11B-406. Curb ramps may be perpendicular, parallel, or a combination of perpendicular and parallel.
11B-406.1.1 Perpendicular curb ramps. Perpendicular curb ramps shall comply with Section 11B-406.2.
11B-406.1.2 Parallel curb ramps. Parallel curb ramps shall comply with Section 11B-406.3.
11B-406.1.3 Blended transitions. Blended transitions shall comply with Section 11B-406.4.
11B-406.1.4 Islands. Islands shall comply with Section 11B-406.6.
11B-406.2 Perpendicular curb ramps. Perpendicular curb ramps shall comply with Sections 11B-406.2 and 11B-406.5.
11B-406.2.1 Slope. Ramp runs shall have a running slope not steeper than 1:12.
CBC § 303.3 High relevance — show source text
ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMMODATIONS, COMMERCIAL BUILDINGS AND PUBLIC HOUSING
11B- 303.3 Beveled. Changes in level between [1] / 4 inch (6.4 mm) high minimum and [1] / 2 inch ( 12.7 mm) high maximum shall be beveled with a slope not steeper than 1:2.
FIGURE 11B- 303.3—BEVELED CHANGE IN LEVEL
11B- 303.4 Ramps. Changes in level greater than [1] / 2 inch ( 12.7 mm) high shall be ramped, and shall comply with Section 11B- 405 or 11B- 406 .
11B-303.5 Warning curbs. Abrupt changes in level exceeding 4 inches (102 mm) in a vertical dimension between walks, sidewalks or other pedestrian ways and adjacent surfaces or features shall be identified by warning curbs at least 6 inches (152 mm) in height above the walk or sidewalk surface.
Exceptions:
1. A warning curb is not required between a walk or sidewalk and an adjacent street or driveway. 2. A warning curb is not required when a guard or handrail is provided with a guide rail centered 2 inches (51 mm) minimum and 4 inches (102 mm) maximum above the surface of the walk or sidewalk.
SECTION 11B- 304 — TURNING SPACE
11B- 304.1 General. Turning space shall comply with Section 11B- 304 .
11B- 304.2 Floor or ground surfaces. Floor or ground surfaces of a turning space shall comply with Section 11B- 302. Changes in level, slopes exceeding 1:48, and detectable warnings shall not be permitted.
Exception: Reserved.
11B- 304.3 Size. Turning space shall comply with Section 11B- 304.3.1 or 11B- 304.3.2.
11B- 304.3.1 Circular space. The turning space shall be a space of 60 inches ( 1524 mm) diameter minimum. The space shall be permitted to include knee and toe clearance complying with Section 11B- 306 .
11B- 304.3.2 T-Shaped space. The turning space shall be a T-shaped space within a 60 inch ( 1524 mm) square minimum with arms and base 36 inches ( 914 mm) wide minimum. Each arm of the T shall be clear of obstructions 12 inches (305 mm) minimum in each direction and the base shall be clear of obstructions 24 inches (610 mm) minimum. The space shall be permitted to include knee and toe clearance complying with Section 11B- 306 only at the end of either the base or one arm .
FIGURE 11B- 304.3.2—T-SHAPED TURNING SPACE
11B- 304.4 Door swing. Doors shall be permitted to swing into turning spaces.
SECTION 11B- 305 — CLEAR FLOOR OR GROUND SPACE
CBC § 11A-3 High relevance — show source text
If a curb ramp is located where pedestrians must walk across the ramp, then it shall have flared sides; the maximum slope of the flare shall be 1 unit vertical in 10 units horizontal (10-percent slope). Curb ramps with returned curbs may be used where pedestrians would not normally walk across the ramp. See Figures 11A-3A through 11A-3L.
1112A.6 Level landing. A level landing 48 inches (1219 mm) deep shall be provided at the upper end of each curb ramp over its full width to permit safe egress from the ramp surface, or the slope of the fanned or flared sides of the curb ramp, shall not exceed 1 unit vertical to 12 units horizontal (8.33-percent slope).
1112A.7 Finish. The surface of each curb ramp and its flared sides shall be stable, firm and slip-resistant and shall be of contrasting finish from that of the adjacent sidewalk.
1112A.8 Border. All curb ramps shall have a grooved border 12 inches (305 mm) wide at the level surface of the sidewalk along the top and each side approximately [3] / 4 inch (19 mm) on center. All curb ramps constructed between the face of the curb and the street shall have a grooved border at the level surface of the sidewalk. See Figures 11A-3A through 11A-3K.
1112A.9 Detectable warnings. See Chapter 11B.
SECTION 1113A—WALKS AND SIDEWALKS ON ACCESSIBLE ROUTES
1113A.1 Width and continuous surface. Walks and sidewalks subject to this chapter shall have a continuous common surface, not inter- rupted by steps or by abrupt changes in level exceeding [1] / 2 inch (12.7 mm). (See Section 1111A).
Walking surfaces shall be stable, firm and slip resistant, and shall comply with Section 1110A.3.
1113A.1.1 Width. Walks and sidewalks shall be a minimum of 48 inches (1219 mm) in width, except that walks serving an individual dwelling unit in covered multifamily buildings may be reduced to 36 inches (914 mm) in clear width except at doors.
1113A.1.2 Surface cross slopes. Surface cross slopes shall not exceed 1 unit vertical in 48 units horizontal (2.083-percent slope).
2025 CALIFORNIA BUILDING CODE 11A-9
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
HOUSING ACCESSIBILITY
1113A.2 Walks with continuous gradients. All walks on an accessible route with continuous gradients shall have level areas at least 60 inches (1524 mm) in length at intervals of at least every 400 feet (122 m).
1113A.3 Five percent gradient. When the slope in the direction of travel of any walk on an accessible route exceeds 1 unit vertical in 20 units horizontal (5-percent slope), it shall comply with the ramp provisions of Section 1114A.
CBC § 1112A.2 High relevance — show source text
1112A.2 Obstructions. Curb ramps shall be located or protected to prevent obstruction by parked cars. Built-up curb ramps shall be located so that they do not project into vehicular traffic lanes, parking spaces or the adjacent loading and unloading access aisle.
1112A.3 Width of curb ramps. Curb ramps shall be a minimum of 48 inches (1219 mm) in width.
1112A.4 Diagonal curb ramps. If diagonal (or corner-type) curb ramps have returned curbs or other well-defined edges, such edges shall be parallel to the direction of pedestrian flow. The bottom of diagonal curb ramps shall have a 48-inch (1219 mm) minimum clear space as shown in Figures 11A-3A through 11A-3L. If diagonal curb ramps are provided at marked crossings, the 48-inch (1219 mm) clear space shall be within the markings (see Figures 11A-3A through 11A-3L). If diagonal curb ramps have flared sides, they shall also have at least a 24-inch-long (610 mm) segment of straight curb located on each side of the curb ramp and within the marked crossing. See Figures 11A-3A through 11A-3L.
1112A.5 Slope of curb ramps. The slope of curb ramps shall not exceed 1 unit vertical to 12 units horizontal (8.33-percent slope) and shall lie, generally, in a single sloped plane. Transitions from ramps to walks, gutters or streets shall be flush and free of abrupt changes. Maximum slopes of adjoining gutters, road surface immediately adjacent to the curb ramp, or accessible route shall not exceed 1 unit vertical to 20 units horizontal (5-percent slope) within 4 feet (1219 mm) of the top and bottom of the curb ramp.
If a curb ramp is located where pedestrians must walk across the ramp, then it shall have flared sides; the maximum slope of the flare shall be 1 unit vertical in 10 units horizontal (10-percent slope). Curb ramps with returned curbs may be used where pedestrians would not normally walk across the ramp. See Figures 11A-3A through 11A-3L.
1112A.6 Level landing. A level landing 48 inches (1219 mm) deep shall be provided at the upper end of each curb ramp over its full width to permit safe egress from the ramp surface, or the slope of the fanned or flared sides of the curb ramp, shall not exceed 1 unit vertical to 12 units horizontal (8.33-percent slope).
1112A.7 Finish. The surface of each curb ramp and its flared sides shall be stable, firm and slip-resistant and shall be of contrasting finish from that of the adjacent sidewalk.
1112A.8 Border. All curb ramps shall have a grooved border 12 inches (305 mm) wide at the level surface of the sidewalk along the top and each side approximately [3] / 4 inch (19 mm) on center. All curb ramps constructed between the face of the curb and the street shall have a grooved border at the level surface of the sidewalk. See Figures 11A-3A through 11A-3K.
1112A.9 Detectable warnings. See Chapter 11B.
SECTION 1113A—WALKS AND SIDEWALKS ON ACCESSIBLE ROUTES
CBC § 11B-206.2.18 High relevance — show source text
11B-206.2.18 Area of sport activity. An accessible route shall be provided to the boundary of each area of sport activity.
11B-206.2.19 Pedestrian street crossings. Where walks or sidewalks are provided, a curb ramp, blended transition or a combina- tion of curb ramps and blended transitions complying with Section 11B-406 shall connect the walks or sidewalks at each pedestrian street crossing. The curb ramp (excluding any flared sides) or blended transition shall be contained wholly within the width of the pedestrian street crossing served.
Exception: Compliance with Section 11B-206.2.19 shall not be required where pedestrian crossing is prohibited by the appropriate administrative authority.
11B- 206.3 Location. Accessible routes shall coincide with or be located in the same area as general circulation paths. Where circulation paths are interior, required accessible routes shall also be interior. An accessible route shall not pass through kitchens, storage rooms, restrooms, closets or other spaces used for similar purposes, except as permitted by Chapter 10.
11B- 206.4 Entrances. Entrances shall be provided in accordance with Section 11B- 206.4. Entrance doors, doorways and gates shall comply with Section 11B- 404 and shall be on an accessible route complying with Section 11B- 402 .
Exceptions:
Reserved.
Reserved.
11B- 206.4.1 Entrances. All entrances shall comply with Section 11B- 404 .
11B- 206.4.2 Parking structure entrances. Where direct access is provided for pedestrians from a parking structure to a building or facility entrance, each direct access to the building or facility entrance shall comply with Section 11B- 404 .
11B- 206.4.3 Entrances from tunnels or elevated walkways. Where direct access is provided for pedestrians from a pedestrian tunnel or elevated walkway to a building or facility, all entrances to the building or facility from each tunnel or walkway shall comply with Section 11B- 404 .
11B- 206.4.4 Transportation facilities. In addition to the requirements of Sections 11B- 206.4.2, 11B- 206.4.3 and 11B- 206.4.5 through 11B- 206.4.9, transportation facilities shall provide entrances in accordance with Section 11B- 206.4.4.
11B-14 2025 CALIFORNIA BUILDING CODE
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ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMMODATIONS, COMMERCIAL BUILDINGS AND PUBLIC HOUSING
11B- 206.4.4.1 Location. In transportation facilities, where different entrances serve different transportation fixed routes or groups of fixed routes, entrances serving each fixed route or group of fixed routes shall comply with Section 11B- 404 .
Exception: Entrances to key stations and existing intercity rail stations retrofitted in accordance with 49 CFR 37.49 or 49 CFR 37.51 shall not be required to comply with Section 11B- 206.4.4.1.
CBC § 1006.3 High relevance — show source text
Exception: Golf car passages complying with Section 11B- 1006.3 shall be permitted to be used for all or part of accessible routes required by Section 11B- 206.2.15.
11B- 206.2.16 Miniature golf facilities. Holes required to comply with Section 11B- 239.2, including the start of play, shall be on an accessible route. Accessible routes serving miniature golf facilities shall comply with Division 4 except as modified by Section 11B- 1007.2.
11B- 206.2.17 Play areas. Play areas shall provide accessible routes in accordance with Section 11B- 206.2.17. Accessible routes serving play areas shall comply with Division 4 except as modified by Section 11B- 1008.2.
11B- 206.2.17.1 Ground level and elevated play components. At least one accessible route shall be provided within the play area. The accessible route shall connect ground level play components required to comply with Section 11B- 240.2.1 and elevated play components required to comply with Section 11B- 240.2.2, including entry and exit points of the play components.
11B- 206.2.17.2 Soft contained play structures. Where three or fewer entry points are provided for soft contained play structures, at least one entry point shall be on an accessible route. Where four or more entry points are provided for soft contained play structures, at least two entry points shall be on an accessible route.
11B-206.2.18 Area of sport activity. An accessible route shall be provided to the boundary of each area of sport activity.
11B-206.2.19 Pedestrian street crossings. Where walks or sidewalks are provided, a curb ramp, blended transition or a combina- tion of curb ramps and blended transitions complying with Section 11B-406 shall connect the walks or sidewalks at each pedestrian street crossing. The curb ramp (excluding any flared sides) or blended transition shall be contained wholly within the width of the pedestrian street crossing served.
Exception: Compliance with Section 11B-206.2.19 shall not be required where pedestrian crossing is prohibited by the appropriate administrative authority.
11B- 206.3 Location. Accessible routes shall coincide with or be located in the same area as general circulation paths. Where circulation paths are interior, required accessible routes shall also be interior. An accessible route shall not pass through kitchens, storage rooms, restrooms, closets or other spaces used for similar purposes, except as permitted by Chapter 10.
11B- 206.4 Entrances. Entrances shall be provided in accordance with Section 11B- 206.4. Entrance doors, doorways and gates shall comply with Section 11B- 404 and shall be on an accessible route complying with Section 11B- 402 .
Exceptions:
Reserved.
Reserved.
11B- 206.4.1 Entrances. All entrances shall comply with Section 11B- 404 .
CBC § 1.1.3.2 High relevance — show source text
Exceptions:
1. Replacement of less than 20 percent of existing detectable warnings at a single contiguous location shall be permit- ted to be in-kind at existing curb ramps, islands or cut-through medians with detectable warnings in compliance with the code requirements in effect at the time of installation.
2. Existing installed detectable warnings at curb ramps, islands or cut-through medians may comply with Section 11B- 705.1.1.3.2 in lieu of Section 11B-705.1.1.3.1.
11B-705.1.1.3.1 Detectable warning surfaces shall be yellow and approximate 33538 of SAE AMS-STD-595A.
11B-705.1.1.3.2 Detectable warning surfaces shall provide a 70 percent minimum visual contrast with adjacent walking surfaces. Contrast in percent shall be determined by:
Contrast percent = [(B1-B2)/B1] × 100 where
B1 = light reflectance value (LRV) of the lighter area and
B2 = light reflectance value (LRV) of the darker area.
Exception: Where the detectable warning surface does not provide a 70 percent minimum contrast with adjacent walking surfaces, a 1-inch (25 mm) wide minimum visually contrasting surface shall separate the detectable warning from adjacent walking surfaces. The visually contrasting surface shall contrast with both the detectable warning and adjacent walking surfaces, either light-on-dark or dark-on-light.
11B-705.1.1.4 Resiliency. Detectable warning surfaces shall differ from adjoining surfaces in resiliency or sound-on-cane contact.
Exception: Detectable warning surfaces at curb ramps, islands or cut-through medians shall not be required to comply with Section 11B-705.1.1.4.
11B-108 2025 CALIFORNIA BUILDING CODE
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ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMMODATIONS, COMMERCIAL BUILDINGS AND PUBLIC HOUSING
11B-705.1.2 Locations. Detectable warnings at the following locations shall comply with Section 11B-705.1.
11B-705.1.2.1 Platform edges. Detectable warning surfaces at platform boarding edges shall be 24 inches (610 mm) wide and shall extend the full length of the public use areas of the platform.
11B-705.1.2.2 Curb ramps. Detectable warnings at curb ramps shall comply with Section 11B-705.1.2.2.
11B-705.1.2.2.1 Perpendicular curb ramps. Detectable warnings at curb ramps shall extend 36 inches (914 mm) in the direc- tion of travel. Detectable warnings shall extend the full width of the ramp run less 2 inches (51 mm) maximum on each side, excluding any flared sides. Detectable warnings shall be located so the edge nearest the curb is 6 inches (152 mm) minimum and 8 inches (203 mm) maximum from the demarcation line at the face of the curb between the curb and the gutter, street or highway.
CBC § 0.249 Medium relevance — show source text
24
|0.249
|0.048
|–
| |4.94|0.326|0.063|–| |5.65|0.413|0.080|–| |6.36|0.507|0.098|–| |7.06|0.611|0.118|0.030| |7.77|0.723|0.139|0.035| |8.47|0.843|0.162|0.041| |9.18|0.969|0.187|0.047| |9.89|1.108|0.212|0.053| |10.59|1.252|0.240|0.060| |12.36|1.647|0.315|0.079| |14.12
|2.090
|0.398
|0.100
| |15.89
|2.580
|0.490
|0.123
| |17.66|3.116|0.591|0.148| |19.42|–|0.701|0.176| |21.19|–|0.818|0.205| |22.95|–|0.944|0.236| |24.72|–|1.078|0.268| |28.25|–|1.369|0.341| |31.78|–|1.690|0.421| |35.31|–|2.043|0.509| |38.84|–|2.425|0.603| |42.37|–|2.838|0.705| |45.90
|–
|3.280
|0.814
| |49.43|–|3.751|0.929| |52.97|–|4.249|1.052| |56.50|–|–|1.181| |60.03|–|–|1.318| |63.56|–|–|1.461| |67.09|–|–|1.611| |70.62|–|–|1.768| |81.21|–|–|2.276| |88.28|–|–|2.647| |95.34|–|–|3.044|FLOW RATE
(SCFM)1PRESSURE DROP (psi) PER 100 FEET2 Col3 Col4 FLOW RATE
(SCFM)11⁄2 INCH PIPE 3⁄4 INCH PIPE 1 INCH PIPE 5.30 0.126 0.024 – 10.59 0.430 0.082 – 15.89 0.886 0.168 – 21.19 1.485 0.281 – 26.48 2.220 0.419 – 31.78 3.089 0.581 – 37.08 4.087 0.766 – 42.37 – 0.975 – 47.67 – 1.206 – 52.97 – 1.460 0.361 58.26 – 1.736 0.429 63.56 – 2.033 0.502 68.85 – 2.
Frequently asked questions
Do blended transitions have the same detectable‑warning requirements as curb ramps?
Yes. Blended transitions require detectable warnings 36 inches deep and extending the width of the transition; see § 11B-705.1.2.5 and the curb‑ramp requirement § 11B-406.5.12.
Can a vertical change of 3/8 inch be left unmodified?
No. A change greater than 1/4 in and up to 1/2 in must be beveled with a slope not steeper than 1:2 per § 11B-303.3.
Is a 1:15 ramp acceptable as a curb ramp if space is limited?
No. Perpendicular and parallel curb ramp runs are limited to 1:12 maximum slope; blended transitions may be 1:20 maximum. If you cannot meet 1:12, you must consider alternate geometry (parallel/diagonal) or document technical infeasibility and use approved alternatives (§ 11B-406.2.1; § 11B-406.4.1).
Where must the ramp (excluding flared sides) be located relative to the marked crossing?
The curb ramp (excluding any flared sides) or blended transition must be contained wholly within the width of the pedestrian street crossing it serves (§ 11B-206.2.19).
When is a landing at the top of a curb ramp not required?
The landing described in § 11B-406.5.3 is not required for parallel curb ramps (the section includes this specific exception).
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