2.5 Protruding Objects and Vertical Clearance
Key Takeaways
Objects with leading edges more than 27 inches and not more than 80 inches above the floor may protrude 4 inches maximum into a circulation path; handrails may protrude 4 1/2 inches.
Objects on single posts or pylons may overhang 4 inches between 27 and 80 inches; objects between posts more than 12 inches apart must have their lowest edge at 27 inches maximum or 80 inches minimum.
Vertical clearance is 80 inches minimum; where it is less, a rail or barrier with its leading edge 27 inches maximum above the floor is required.
Door closers and door stops may be 78 inches minimum above the floor.
Protruding objects may not reduce the required clear width of an accessible route (A117.1 307.5); IBC 1003.3 applies similar limits to all means of egress.
2.5 Protruding Objects and Vertical Clearance
Protruding Objects carries 2% of the ICC 21 outline. The rules protect people who are blind or have low vision. A long cane sweeps the floor and detects objects whose leading edge is at or below about 27 inches. Anything mounted higher can strike the head or torso before the cane finds it, so A117.1 Section 307 limits how far such objects may project.
Where Section 307 Applies
Section 307.1 applies to protruding objects on circulation paths. A117.1 defines a circulation path as an exterior or interior way of passage for pedestrian travel, including walks, hallways, courtyards, elevators, platform lifts, ramps, stairways and landings. That is broader than the accessible route: an inaccessible stairway is still a circulation path, and the space beneath it is regulated. The IBC applies the same concept to every means of egress in Section 1003.3.
The Core Numbers
| Rule | Section | Requirement |
|---|---|---|
| Protrusion limit | 307.2 | Leading edge more than 27 in. and not more than 80 in. above the floor: 4 in. maximum horizontal protrusion |
| Handrail exception | 307.2 Exception | Handrails may protrude 4 1/2 in. |
| Post-mounted objects | 307.3 | Objects on posts or pylons may overhang 4 in. maximum between 27 and 80 in. |
| Multiple posts | 307.3 | Where posts or pylons are more than 12 in. apart, the lowest edge of the object must be 27 in. maximum or 80 in. minimum |
| Sloping handrails | 307.3 Exception | Sloping portions of handrails between the top and bottom risers of stairs and above ramp runs are not required to comply with 307.3 |
| Vertical clearance | 307.4 | 80 in. minimum; where less, provide rails or barriers with the leading edge 27 in. maximum above the floor |
| Door hardware | 307.4 Exception | Door closers and door stops may be 78 in. minimum above the floor |
| Route width | 307.5 | Protruding objects may not reduce the clear width required for accessible routes |
Reading the Zones
| Height of leading edge | Allowed projection | Reason |
|---|---|---|
| 27 in. or lower | Any, as long as route width is preserved | The cane detects it |
| Above 27 in. through 80 in. | 4 in. maximum | The cane would pass under it |
| Above 80 in. | Any | It is above head height |
Common Field Conditions
- Fire extinguisher cabinets and AED cabinets: A surface-mounted cabinet with its bottom at 48 inches that projects 7 inches violates 307.2. Use a recessed or semi-recessed cabinet projecting 4 inches maximum, or add a cane-detectable element (a wing wall or a fixed object) whose leading edge is at 27 inches or lower.
- Wall-hung drinking fountains: A117.1 Section 602.1 makes wheelchair-height and standing-height drinking fountains comply with Section 307. A wheelchair-height unit needs 27 inches of knee clearance at its front edge, so its leading edge sits at the cane-detection boundary; a standing-height unit, or any unit whose leading edge is higher than 27 inches, must be in an alcove or protected by wing walls or another cane-detectable element.
- Open stairways: The underside of a stair within a corridor or lobby creates headroom below 80 inches. Provide a rail, planter or wall so the space with less than 80 inches of headroom is guarded at 27 inches or lower.
- Signs on two posts: A wayfinding sign on two posts 30 inches apart with its bottom edge at 40 inches violates 307.3. Lower the sign panel's bottom to 27 inches or less, raise it to 80 inches, or add a cane-detectable rail between the posts.
- Door closers: An overhead closer arm at 78 1/2 inches complies under the 307.4 exception even though it is below 80 inches.
Worked Example
A corridor has a clear width of 44 inches. A wall-mounted display case projects 4 inches with its bottom edge at 36 inches, and a second case on the opposite wall projects 4 inches at the same height.
- Each case satisfies 307.2 (4 inches maximum between 27 and 80 inches).
- Section 307.5 requires the accessible route clear width to remain. 44 - 4 - 4 = 36 inches. An interior route needs 36 inches minimum (403.5.1), so the corridor still complies as an accessible route.
- If the corridor were an exterior route, 48 inches would be required and the cases would cause a violation.
Relationship to Other Sections
- Handrail extensions at stairs and ramps must not create hazards; Section 505.3 directs handrails that are not continuous to comply with Section 307.
- Elevator hall call buttons must not have objects beneath them protruding more than 1 inch (407.2.1).
- Signs and fixtures in toilet rooms, such as mirrors and dispensers, still follow 307 if they are along a circulation path within the room.
Exam Traps
- "Objects below 27 inches may project any distance" is true only if the required route width is maintained.
- The handrail allowance is 4 1/2 inches, not 4 inches.
- The post rule turns on 12 inches between posts, not 24.
- Headroom is 80 inches, except door closers and stops at 78 inches.
A wall-mounted AED cabinet along a corridor has its bottom edge 42 inches above the floor. What is the maximum distance it may protrude into the circulation path under ICC A117.1 Section 307.2?
4 inches
4 1/2 inches
6 inches
8 inches
A directory sign is mounted between two posts that are 36 inches apart. Which bottom edge height complies with ICC A117.1 Section 307.3?
30 inches above the floor
54 inches above the floor
78 inches above the floor
26 inches above the floor
An overhead door closer arm is 78 1/2 inches above the floor in a doorway on an accessible route. How does A117.1 Section 307.4 treat it?
It violates the 80-inch vertical clearance requirement and must be raised
It complies; closers and stops may be 78 inches minimum above the floor
It complies only if a barrier is installed at 27 inches
It complies only in existing buildings
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