Case study question

On this question in the case study it says that the ibc code says 15sf net for unconcentrated standing space but isn’t it 5sf net for standing spaces with assembly without fixed seats?
In the ibc code there’s a little gap in the assembly space without fixed seats can you clarify which sf is for what in this part of the chart in ibc 1004.5?

The client recently asked the architect about changing the community room from standing space to a space with a fixed seating layout with 52 seats.

What is the impact on code analysis?

The separation requirement will increase to three hours

Incorrect. A three-hour rating is not required at the new meeting room per IBC table 508.4.

A second exit is now required

Correct. First, we need to find the area and determine the occupancy type of this space. The meeting room is 30 feet by 24 feet, which is 720 square feet. Per IBC Chapter 3, a meeting hall is an assembly (or “A”) occupancy. Per Table 1004.5 of the IBC, unconcentrated standing space is calculated at 15 net square feet per person. Therefore, the occupant load of the space as currently designed is:

720 sf / 15 sf per person = 48 occupants

If this is changed to fixed seating, then occupancy is based on the number of seats (see IBC section 1004.6). Therefore, the new occupant load of the space would be 52 occupants.

Per Table 1006.2.1, a single exit is permitted in an assembly space (such as this community room) only if a space has 49 occupants or less. Therefore, a second exit is needed for this space if the revision that the client asked about is made.

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Hi @sergioclaure93 ,

Thanks for posting! @coachchrishopstock can you please take a look at this question and see if you can assist?


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hi @sergioclaure93 - can you please PM me a screenshot of this question and I’ll look into it for you? I’m having trouble locating it.

Sure I attached the screenshot. It’s from the case study, in the ibc code is standing space 5 net or 15net?
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Thanks @sergioclaure93
There’s a note on the floor plan for this case study that notes the conference room is ‘unconcentrated standing room’. Therefore, we use 15 net square feet per occupant per 2018 IBC table 1004.5. The word ‘unconcentrated’ is important here and is the reason we use 15nsf vs 5nsf (which would be more appropriate for a concert venue, for example).

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Ok I see cause the key word unconcentrated and match that in the ibc code, makes sense thanks.

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