Means of egress design

[Sifu]

Consider a tenant space with several offices, occupancy B with an occupancy load of 30, that also has two conference rooms, occupancy A with loads of 20 each. 2012 IBC 303.1.2 allows the conference rooms to be considered as part of the B occupancy. Does that entire tenant space require two exits? In other words, would you add the area of the conference rooms to the area of the offices, divide by 100 and get to the occupant load, or calculate them separately, add the number of occupants and provide exits according to that number?
for example:

Calculated separately, the total occ load =70, per t1015.1, 2 exits required from the "space"
3000s.f. offices/100=30
300s.f. conference room/15=20
300s.f. conference room/15=20

Calculated cumulatively, 3600s.f./100 =36, one exit required.

Seems like I should know this but I have a problematic T/I and this is part of it. I think I remember that this has been addressed by the code but I can't seem to find it. Code sections will help if there are any.

Seems like just one exit required but I think about a space with lots of small conference rooms and a few offices that could have a much higher occ load trying to get out that one exit. I guess that could change the "accessory" function and maybe flip the calculation.

 

[mtlogcabin]

1004.6 Multiple occupancies.
Where a building contains two or more occupancies, the means of egress requirements shall apply to each portion of the building based on the occupancy of that space. Where two or more occupancies utilize portions of the same means of egress system, those egress components shall meet the more stringent requirements of all occupancies that are served.

70 is the correct number for your project and would require two exits
The small conference room is classified as a "B" occupancy which means "A" occupancy code requirements are not applicable such as sprinklers, alarms and notification appliances

 

[mtlogcabin]

[A] 107.2.3 Means of egress.
The construction documents shall show in sufficient detail the location, construction, size and character of all portions of the means of egress including the path of the exit discharge to the public way in compliance with the provisions of this code. In other than occupancies in Groups R-2, R-3, and I-1, the construction documents shall designate the number of occupants to be accommodated on every floor, and in all rooms and spaces.

 

[cda]

Are you saying the example building is

3000 total sq ft

Or

3600 total sq ft

 

[cda]

Plus if there is say a conference table and designated chairs, you could go by chair count

 

[Sifu]

The total T/I space is over 14,000s.f., broken up into a convoluted mess, taking up 2/3 of an office building floor. The area I am concerned with the most is on one end, has two conference rooms (which would serve the entire space) and the only exit they are providing swings in. I believe they need two doors, both swinging in the direction of travel. They have other doors (9) available, some within travel distances but they also swing in. I am sending them a comment to provide 2 out-swing doors for that space, I think the rest, as ugly as it is, meets code. As far as the count, I am allowing them to use chair count, using what they provided in the ventilation schedule, it still goes over the 49. Like I said, it is a mess.

 

[cda]

So same question for area in question



Are you saying

3000 total sq ft

Or

3600 total sq ft

 

[IJHumberson]

Chair count is not permitted unless it is fixed seating (i.e. bolted in place, as in a movie theater). mtlogcabin is correct - the occupant load is 70.

 

[steveray]

If they are small conference rooms I would do the whole thing at 100 per...

 

[cda]

Exception: Where approved by the building official, the actual number of occupants for whom each occupied space, floor or building is designed, although less than those determined by calculation, shall be permitted to be used in the determination of the design occupant load.

 

[steveray]

Let me clarify, if the rooms themselves (individually) do not cross the "A" threshold (even at 15 per), I would do the whole thing at 100 sqft per occupant

 

[JPohling]

1/15 at the conference rooms and 1/100 at the balance of business occupancy. I agree on the 70 occupants

 

[PJC89]

Every occupant on every story is required to have access to a minimum of two exits (i.e., exit stairway, exit access stairway, exterior exit door, horizontal exit, etc.) Occupants are required to have two exits from a space depending on the occupant load within the space and the common path of travel within the space before the occupant has the choice between two remote exits. Refer to Table 1006.2.1 for when two exits are required from a space:

https://up.codes/viewer/general/int_building_code_2015/chapter/10/means-of-egress#1006