# Occupant distribution to exits



## manifold (May 8, 2018)

IBC 2012

I have a room with 28 occupants, one exit is required.  It has two doors, one is an exit directly to the exterior, the other is exit access to an unrated corridor with an exit at either end.  

Can I show that all 28 occupants in this room will exit through the door directly to the exterior? Or do I need to divide the occupants 50/50 between the 2 doors? 

Also, the building is arranged such that about 2/3 of the occupants would naturally use one of the corridor egress doors (due to where the stair from the second story terminates), while the other 1/3 would naturally use the other.  Would I calculate number of occupants at these 2 egress doors based on the likely path (which creates a more stringent condition at one of the doors) or split all occupants 50/50 between to 2 corridor egress doors?


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## mtlogcabin (May 8, 2018)

split them 50/50. If the corridor OL is over 30 and non-sprinklered then you have to rate the corridor


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## cda (May 8, 2018)

I have never seen anyone come up
With a plan on how to herd people one way or another.


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## JBI (May 8, 2018)

IF the only 'EXIT' sign is over the door to the exterior then folks will go through that door in an emergency, and the corridor rating MAY not be required. 
I've seen numerous posts that talk about splitting the occupants between available doors, but not sure what Code section addresses that. 
IF there is one MOE required and ONE provided, then other doors are not part of the required MOE. JMHO


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## manifold (May 8, 2018)

JBI said:


> IF the only 'EXIT' sign is over the door to the exterior then folks will go through that door in an emergency, and the corridor rating MAY not be required.
> I've seen numerous posts that talk about splitting the occupants between available doors, but not sure what Code section addresses that.
> IF there is one MOE required and ONE provided, then other doors are not part of the required MOE. JMHO


This was my take on it.  The exterior door has an 'EXIT' sign, the interior door does not.


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## cda (May 8, 2018)

manifold said:


> IBC 2012
> 
> I have a room with 28 occupants, one exit is required.  It has two doors, one is an exit directly to the exterior, the other is exit access to an unrated corridor with an exit at either end.
> 
> ...




So is this a new or existing building

Or remodel

Are you trying to avoid rating the corridor??


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## manifold (May 8, 2018)

cda said:


> So is this a new or existing building
> 
> Or remodel
> 
> Are you trying to avoid rating the corridor??


New building.  Sprinklered.  Corridor rating is not an issue. 

One of the egress doors at the vestibule needs to swing in so I need to show that it serves less than 50 occupants.


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## cda (May 8, 2018)

manifold said:


> New building.  Sprinklered.  Corridor rating is not an issue.
> 
> One of the egress doors at the vestibule needs to swing in so I need to show that it serves less than 50 occupants.




Oh

So one story building??

If so how many sq ft


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## mtlogcabin (May 8, 2018)

Since the corridor is for access and egress then the OL in the corridor is 28 serving that room only. 
Exit signs are not required in a room of that size
Both doors are egress doors and we know most people will exit back through the door they entered sign or no sign 

1008.1 Doors.
Means of egress doors shall meet the requirements of this section. Doors serving a means of egress system shall meet the requirements of this section and Section 1020.2. Doors provided for egress purposes in numbers greater than required by this code shall meet the requirements of this section.

1005.5. Distribution of egress capacity.
Where more than one exit, or access to more than one exit, is required, the means of egress shall be configured such that the loss of any one exit, or access to one exit, shall not reduce the available capacity to less than 50 percent of the required capacity.
_If you use the 50/50 split you should have an equal number of occupants at all exits no matter how many you provide_


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## manifold (May 8, 2018)

cda said:


> Oh
> 
> So one story building??
> 
> If so how many sq ft


2 Story, 12,500 SF; Group B, F-1, and S-1 - unseparated


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## cda (May 8, 2018)

With that sq ft, Not sure how you will get the door swing like you want it.

You can always submit it and see what happens


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## RLGA (May 8, 2018)

Per the section quoted by mtlogcabin, there is an element of that requirement that is overlooked (highlighted below):

"1005.5. Distribution of egress capacity. _Where more than one exit, or access to more than one exit,_ *is required,* the means of egress shall be configured such that the loss of any one exit, or access to one exit, shall not reduce the available capacity to less than 50 percent of the required capacity."​There is nothing in the IBC that states occupants are required to be distributed evenly among all available exit and/or exit access doorways whether required or not, as long as the 50% rule is maintained when two or more exit/exit access doorways are required. Group A occupancies with an occupant load greater than 300 have occupant load distribution requirements that are slightly different.

If the space only requires one means of egress, then all occupants can be shown using the one exit, even though another door provided. However, that other door must comply with all requirements for a means of egress door.


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## sergoodo (May 8, 2018)

If the room complies with 1015.1, no need to divide the occupants and add 1/2 the load to corridor:
*2012 IBC*
1021.2 Exits from stories.
Exceptions:
1. Rooms, areas and spaces complying with Section 1015.1 with exits that discharge directly to the exterior at the level of exit discharge, are permitted to have one exit.


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