Exit Discharge from Interior Exit Stair Remoteness or Separation Distance Requirement?

[Harrison Staab]

For a 5 story (not a high rise) Type III Group R-2 Apartment building fully sprinklered per NFPA 13 in sunny California (CBC 2019):

Project has two Interior Exit Stairways connected by a 1-hr corridor exceeding the separation requirement of 1007.1.1 (>1/3 building diagonal per exception 2). Due to the building form (L-shape building) the exit discharge doors were flagged by a plan reviewer as too close (~15', well below the 1/3 of the building diagonal). At the level of Exit Discharge, there are several other exits provided for occupants of that level, so the issue is only regarding the two means of egress for the levels above. The reviewer cited 1007.1.3, however this is only applicable to Exit Access Stairways. I'm not able to find anything in the code, IBC 2021 commentary, or various online references indicating if there is some remoteness or separation distance requirement for these Exit Discharge doors themselves.

Anyone aware of such a requirement?

See attached diagrammatic plan.

 

[chris macko]

It's not the exact wording, but 1028.2 exception 1.4 seems to hint at the true intent. It calls for 30ft between points of exit discharge or 1/4 of the diagonal.

 

[RLGA]

Although I do not like the arrangement (creates a potential choke point), the code does not prohibit your position.

The "exit doorways" are considered those doors that lead into the exit stairway. You have separated them according to Section 1007.1.1, Exceptions 1 and 2. Section 1023.3 states that exit stairways "shall terminate at an exit discharge." There is no requirement that the termination (i.e., "exit discharge") be separated under the same conditions as "exit doorways." Further, Section 1028 does not mention any requirements for separation of the exit discharge.

As for the section chris macko pointed out, it does not apply in your situation since you are not exiting through the building from the interior exit stairway.

Interestingly, Section 1028.1, Exception 1.4 (2019 CBC), refers to the door at the end of the stairway as the "exit discharge door"; thus, contradicting the interpretation that the door in question is an exit door by using the mention of "exterior exit doors at the level of exit discharge" in the definition of "Exit" as justification. (Just FYI, that phrase refers to doors that lead directly to the exterior from non-exit components, such as a door from a classroom that opens directly to the exterior.)

Lastly, as you pointed out, Section 1007.1.3 applies only to exit access stairways, which may or may not terminate at an exit discharge; thus, the concern for separation.

Overall, the separation requirements (i.e., Sections 1007 and 1028.1, Exception 1.4) are to ensure that occupants inside the building have adequate access to an exit.

 

[Harrison Staab]

Thanks, RLGA! I appreciate the analysis.

 

[Yikes]

Interestingly, Section 1028.1, Exception 1.4 (2019 CBC), refers to the door at the end of the stairway as the "exit discharge door"; thus, contradicting the interpretation that the door in question is an exit door by using the mention of "exterior exit doors at the level of exit discharge" in the definition of "Exit" as justification. (Just FYI, that phrase refers to doors that lead directly to the exterior from non-exit components, such as a door from a classroom that opens directly to the exterior.)

I'll use this opportunity to give kudos to RLGA. He authored a book called "Applying the Building Code", and the concept of exit discharge is explained well in section 10.3 and 10.4 The book was based on the 2015 IBC, but that portion of the code is still valid in 2023.

Ron, I hope you will publish either an updated edition, or a supplement, for the changes that have occurred in the last 8 years.

 

[RLGA]

I'll use this opportunity to give kudos to RLGA. He authored a book called "Applying the Building Code", and the concept of exit discharge is explained well in section 10.3 and 10.4 The book was based on the 2015 IBC, but that portion of the code is still valid in 2023.

Ron, I hope you will publish either an updated edition, or a supplement, for the changes that have occurred in the last 8 years.

Thank you.

As a first-time author, I fell victim to publishing legalese. I wanted to publish an updated version, but Wiley said they are not interested (apparently, code books are not big sellers). I asked about self-publishing, but Wiley said I could not because of our contract (they have to exhaust their current stock first to avoid a competing publication).

I have not given up completely, but I have been too busy with work and other professional volunteer efforts to give Wiley a hard pushback. If and when things calm down for me, I will approach Wiley again--maybe even get a lawyer involved.

 

[Harrison Staab]

Our firm also has a copy of ABC that remains very helpful to us. I was tickled to find that you are an active member here and appreciate how often you provide thorough commentary and analysis for everyone.

 

[steveray]

(Add) 1028.4.1 Remoteness. Where two or more doors leading to exit discharge are required, a minimum
of two such doors shall be placed a distance apart equal to not less than one-third of the length of the
maximum overall diagonal dimension of the building served, measured in a straight line between doors.
Additional doors leading to exit discharge shall be arranged a reasonable distance apart so that if one
becomes blocked, the others will be available.

Welcome to CT...

 

[Yikes]

Thank you.

As a first-time author, I fell victim to publishing legalese. I wanted to publish an updated version, but Wiley said they are not interested (apparently, code books are not big sellers). I asked about self-publishing, but Wiley said I could not because of our contract (they have to exhaust their current stock first to avoid a competing publication).

In the interim, could you self-publish an e-book that only discusses limited changes to the code since 2015? That way you would not need to reference the original book.

 

[RLGA]

In the interim, could you self-publish an e-book that only discusses limited changes to the code since 2015? That way you would not need to reference the original book.

I still have to go through Wiley--they have the right of first refusal for any new or derivative work.