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Figuring out SF/OCC of a corridor with services multiple uses.

Ryan Schultz

Registered User
Joined
Apr 2, 2012
Messages
266
Location
Madison, WI
Per TABLE 1004.1.2 MAXIMUM FLOOR AREA ALLOWANCES PER OCCUPANT, what would the SF/OCC be in the following condition?


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My best answer: Whatever you can get the AHJ to accept.

Actually, I would use whatever the major occupancy is.

BTW, regarding dormitories, the occupant load factor is really for densely occupied buildings (think old-style military barracks or college dorms with 2 to 4 students in a sleeping unit with no kitchen and only community restrooms and showers. What is commonly built for today’s dormitories are actually apartments (dwelling units) with private baths, a kitchen, and a common living area. I’ve done many of these projects and have used the standard “residential” occupant load factor since they are really apartments and not a dormitory, even though they are occupied by students only.
 
More a general question, as I was trying to tease out how to determine the load from a corridor that serves multiple uses.
 
Seems like for exiting and rating add them all up.

There are a few more times where the number actually matters.
 
Seems like for exiting and rating add them all up.

There are a few more times where the number actually matters.
“Gross area” includes corridors, so an occupant load factor applied to the corridor would be applicable in this situation. However, the question is which occupant load factor. That is why I responded to use the occupant load factor for the major use of the building. If the building only included a small area of mercantile and apartments and the rest of the building was all dormitory, then the dormitory occupant load factor, in my opinion, would be applied to the corridor.
 
“Gross area” includes corridors, so an occupant load factor applied to the corridor would be applicable in this situation. However, the question is which occupant load factor. That is why I responded to use the occupant load factor for the major use of the building. If the building only included a small area of mercantile and apartments and the rest of the building was all dormitory, then the dormitory occupant load factor, in my opinion, would be applied to the corridor.
To revive this, If I have a building with two restaurants, occupant load calculated at 15/net, with a corridor and lobby type area for access to bathrooms and an exit, would I not count the common spaces since it is a net calculation? I have seen examples where you would count them if a gross calculation is used, but net doesn't usually include them. See attached snippet.
 

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To revive this, If I have a building with two restaurants, occupant load calculated at 15/net, with a corridor and lobby type area for access to bathrooms and an exit, would I not count the common spaces since it is a net calculation? I have seen examples where you would count them if a gross calculation is used, but net doesn't usually include them. See attached snippet.
I don't know what you are considering a "lobby" in the snippet, but a lobby where people wait to be seated would be included in determining occupant load. However, what you show on the snippet does appear to be just restrooms and common circulation space, which should not be included in the net floor area.
 
I don't know what you are considering a "lobby" in the snippet, but a lobby where people wait to be seated would be included in determining occupant load. However, what you show on the snippet does appear to be just restrooms and common circulation space, which should not be included in the net floor area.
It is not a lobby where people sit, just a common space providing access to the restrooms and exit. I didn't think it would be counted since both occupancies accessing it are net calculations but wanted to get your opinion Thanks.
 
This is an issue within the IBC in that the table switches from gross to net square footage and the intent of occupant load calculations is based on the function of the space as stated in 1004.1.2.

The real question should be; why should an occupant load be calculated for a corridor since this not a normally occupied area and in this situation is an egress component. Unless the corridor is designed to have some functions within the space, such as a seating area.

Hoping to clarify some of this for the 2024 IBC.
 
They do have a waiting area at the entrance and I am requiring them to calculate that for standing space, but this space is not used for anything other than access to the common toilet rooms.
 
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