1006.2.1 Egress based on occupant load and common path of egress travel distance

[Pak Yip]

2021 IBC Section 1006.2.1 requires that two exit or exit access doorways shall be provided to any space if the design occupant load or the common path of egress travel exceeds the values outlined in Table 1006.2.1.

The classrooms shown in the plan below meet the common egress travel requirements and do not exceed the specified occupant load. However, there will be 180 occupants moving in one direction along the hallway. Do you believe this egress arrangement complies with Section 1006.2.1? The commentary indicates that permitting a single exit depends on the number of occupants at risk, and in some cases, it may be impractical to provide two exits for smaller spaces. What are your thoughts on the cumulative occupancy load in a hallway that only allows movement in one direction toward the exit?

Plan

 

[arwat23]

Do you believe this egress arrangement complies with Section 1006.2.1?

I don't see an issue with 1006.2.1. You have no dead end, common path of egress travel is fine, each room's OL is below what's required for two exits from the rooms, and (I assume) the two building exits are spaced properly.

It would be better from a practical / functional standpoint to have the doors opposite each other (each end of the corridor) in my opinion, or add a third door for easier ingress and egress (assuming that's possible with the site), but that wouldn't be required by code.

 

[steveray]

Interesting....the corridor serves way more than 50 OL.....We wouldn't allow a door to swing in, but we disregard choice of 2 exits.....

 

[Pak Yip]

That’s exactly my concern. While the egress will comply with the CPET and the OL, I don't believe the code intends to allow cumulative OL to flow in one direction toward the exit. It seems very dangerous; if the corridor were blocked, over 100 students would have no options. Also, keep in mind that EERO is not required in Group E.

 

[walker.t]

However, there will be 180 occupants moving in one direction along the hallway. Do you believe this egress arrangement complies with Section 1006.2.1?

I believe the configuration described does comply with 1006.2.1. 1006.2 “Egress From Spaces” makes reference to “rooms, areas or spaces.” It does not include “corridors” - corridors are an exit access component, not an occupied space. As you noted, egress from each of the rooms complies with the requirements for maximum occupant load and common path of egress travel distance per Table 1006.2.1. I don’t think 1006.2.1 is saying that we have to consider the cumulative occupant load at any given point in the corridor to see if we need two paths to exits from that point.

The combined occupant load from the rooms does come into play when determining the occupant load served by the corridor, however.

I don't believe the code intends to allow cumulative OL to flow in one direction toward the exit. It seems very dangerous; if the corridor were blocked, over 100 students would have no options.

I do agree that the large flow of occupants along a common path is not ideal but it seems to me to comply with at least the letter of the code. I’d feel better if there was a door at the left end of the corridor.

 

[Yankee Chronicler]

That’s exactly my concern. While the egress will comply with the CPET and the OL, I don't believe the code intends to allow cumulative OL to flow in one direction toward the exit. It seems very dangerous; if the corridor were blocked, over 100 students would have no options. Also, keep in mind that EERO is not required in Group E.

The code does allow this. That's what the common path of egress travel limitation is all about, and why the common path limitation is so much less than the exit access travel distance limitation. To say otherwise would essentially be saying that the common path limitation should always be zero.

That doesn't mean that all compliant designs are great designs. The plan in this instance is a good example of a plan that complies but is poorly conceived.