Questions on Occupant Load Factor_IBC 1004.1.2

Can someone confirm if the following info from IBC table 1004.1.2 is interpreted correctly ? I’m not too sure which net sf value goes with which sub-space function under the “Assembly without fixed seats” category.

[Assembly without fixed seats ]

Concentrated (Chairs only - not fixed): 7 net
Standing Space: 5 net
Unconcentrated (tables and chairs): 15 net

Also, which sub-space function should apply in the calculation of a Break Room ?

Thank you

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@coachdarionziegler do you mind helping with this question?

Hi @JessicaY,

This is a great question, because the chart in the IBC is not very graphically clear on this!

You are exactly right.
Concentrated (Chairs only - not fixed): 7 net
Standing Space: 5 net
Unconcentrated (tables and chairs): 15 net

The 2015 IBC was a little clearer, but still confusing!
image

For a breakroom I would typically expect the occupancy to be calculated based on 15 net feet as the space is an assembly area with unconcentrated (tables and chairs). As far as occupancy classification goes, I see the use of Break Rooms described as a B occupancy as they usually are considered an accessory use to another, primary use. Although, if the Break Room is large enough with over 50 occupants it may be need to be classified as an A-3 occupancy.

Your question about how to calculate Break Rooms seems to be a popular one! I found a few forums discussing this same topic. I’ve posted them below if you’re interested in learning more:

Hope this helps!
-Darion

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Thanks so much for the info.

Jessica

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Can you clarify which would be the most stringent of these - would it be the 15 net for unconcentrated? Specifically, I’m thinking of a practice question I reviewed which did not specifically state if the assembly space had chairs/tables or not, so I would assume we’d go with the most stringent load noted? Thanks!

Hi @kim.t.luu,

Standing space would be the most stringent assembly space usage at 5 sqft per person.

If a question says “unconcentrated” then I would definitely go with 15. If “concentrated” go with 7. If it’s a function you know will not have either tables or chairs go with 5 for standing space. If it’s a function like a movie theater, then there is another process for calculating the occupancy for spaces with fixed seats.

A lot of times questions on this topic give very sneaky hints about which factor to use. The actual exam (hopefully) won’t leave you to guess blindly!

If you encountered this in a Black Spectacles material feel free to private message me the question (no posting of paid content is allowed on the public boards) and I can see if I can help explain further!

Hope this helps!
-Darion

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