Do I need to comply with the requirements of an Atrium?

[Spiltchaos]

Hell everyone - I have a question about one of the allowable approaches to not require a space open to three levels to comply with the requirements of the 2024 IBC chapter 4, i.e., smoke control, enclosure of the space with fire and/or smoke barriers, etc.

The new building will have a space that consists of a completely open volume from the second level to the third level. From the first level to the second level, the only opening is for an unenclosed exit access stairway through the floor/ceiling asembly. This meets the definition of atrium in the code, as I understand it. The building will be sprinklered and is not an I occupancy.

Here is the code path I went down:

The IBC section 404.1, exception does not require the space to comply with the requirements of 404 if vertical openings comply with Sections 712.1.1 through 712.1.3, and Sections 712.1.9 through 712.1.14.

In this case, only 712.1.12 is what I think would apply. Looking at 712.1.12.

Vertical openings containing exit access stairways or ramps in accordance with Section 1019 shall be permitted.

Section 1019.3 Exception 4, permits the following exception to providing a shaft to enclose the exit access stairway:

Exit access stairways and ramps in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, where the area of the vertical opening between stories does not exceed twice the horizontal projected area of the stairway or ramp and the opening is protected by a draft curtain and closely spaced sprinklers in accordance with NFPA 13. In other than Group B and M occupancies, this provision is limited to openings that do not connect more than four stories.

Question: If we provide the sprinklers and draft curtain and limited opening size between level 1 and 2, per 1019.3 exception 4, is this approach acceptable to no longer meet any of the provisions of 404?

The nuance (and maybe I am going to deep) is that this is not a continuous stair between all the levels with an associated small opening since there is no stair from level 2 to 3. I feel I am meeting the intent of the code but can see where there could be a different interp. that only small openings are allowed for all levels.

Thanks for your time and thoughts.

 

[walker.t]

second level to the third level

I assume you mean “story” when you say “level,” a mezzanine would be a “level” but not a “story.”

Question: If we provide the sprinklers and draft curtain and limited opening size between level 1 and 2, per 1019.3 exception 4, is this approach acceptable to no longer meet any of the provisions of 404?

The code path you outlined demonstrates you do not have to comply with Section 404.

IBC commentary on 2021 IBC 404.1 General (partial quote)
In other words, where compliance with Section 712 is achieved by applying one of the options other than Section 712.1.7 that permits an atrium, then compliance with Section 404 is not required.

The nuance (and maybe I am going to deep) is that this is not a continuous stair between all the levels with an associated small opening since there is no stair from level 2 to 3.

I don’t see how that affects the matter, doesn’t sound like an issue to me.

 

[Spiltchaos]

I assume you mean “story” when you say “level,” a mezzanine would be a “level” but not a “story.”


The code path you outlined demonstrates you do not have to comply with Section 404.



I don’t see how that affects the matter, doesn’t sound like an issue to me.

Thanks for the input, and yes, I did mean story.