ACCESS TO 3 EXITS?

[RLGA]

Normally I defer to you

Just not sure where the line is that moves a training room or classroom from a B to an A


When the only example given is a lecture hall

I am not sure if fifty is that magic number

I have worked on a lot of college and university projects, and every one of those required a Group A-3 occupancy classification for classrooms with occupant loads of 50 or greater (per Group A requirements), whether they were identified as lecture halls or not. However, the occupant load factor used depended on the specific use. For lecture halls and classrooms with fixed seating, the occupant load is based on one occupant per seat and 15sf/occupant for the lectern area. For standard classrooms, the occupant load is based on the "Classroom" occupant load factor under "Educational." Training areas for specific skills (auto maintenance, woodworking, etc.) are classified in their respective occupancy groups because of the dangers associated with those uses, and the occupant load is based on the "Shops and other vocational room areas" occupant load factor under "Educational"; however, I would not change the occupancy group to Group A-3 in those areas when the occupant load exceeded 50.

 

[cda]

Will defer to you

Maybe needs some code clean up???

 

[JPohling]

Regarding the Group B classification for higher education or skill training, the issue is between classifying a space as Group B or E. If 12th grade and below, then it is classified as a Group E. If for higher education (i.e., colleges and universities) and skill training, then they are classified as Group B. However, if the occupant load of a Group B education space is 50 or higher, then it is classified as a Group A-3 to address the issues of a higher, concentrated occupant load. Group E incorporates special life safety requirements that are lacking in Group B requirements; thus, there is an exception in the Group A section in Chapter 3 that does not require Group E to comply with Group A requirements.

As to the original question, I would say no, that not all occupants need access to all three exits. The floor will require three exits, so a third exit will need to be added, but if the area under consideration does not require three exits (i.e., the smaller tenant), then they only need access to two exits. The other, larger tenant, however, will need access to three exits, whether they share two with the other tenant or not.

Don't forget about egress width. The higher occupant load may require wider stairs; or, the new stair may need to be sized to accommodate the difference, as long as it does not provide more than 50% of the required egress width.

Ron, I just met with a senior structural plan checker in the jurisdiction and he is using 2016 CBC 1007.1.2 to determine that all tenants would need access to all three exit stairs. he is stating that if one of the stairs is blocked that the other two would need to be available because the floor requires three exits. This is even if the smaller tenants only require access to two exits based upon their occupant load. 2013 CBC 1021.2.2 seems to have allowed only access to two stairs for the smaller tenants but this section has been removed. Darn! wish that code section still existed!

 

[cda]

Ron, I just met with a senior structural plan checker in the jurisdiction and he is using 2016 CBC 1007.1.2 to determine that all tenants would need access to all three exit stairs. he is stating that if one of the stairs is blocked that the other two would need to be available because the floor requires three exits. This is even if the smaller tenants only require access to two exits based upon their occupant load. 2013 CBC 1021.2.2 seems to have allowed only access to two stairs for the smaller tenants but this section has been removed. Darn! wish that code section still existed!

So what is the Sq ft for these rooms??

 

[JPohling]

Many of the rooms are under 750, one is about 2000. not sure how that makes any difference at all.

 

[cda]

Ok now I feel defeated

RLGA said I was wrong

And the commentary says indirectly I am wrong


Boy what a way to start the weekend.

 

[Sifu]

If you had a multi-story building with occupant loads that did not exceed 500, two exits would be required. If none of the tenant spaces in that building exceeded 49 occupants, would it be allowed to give each of those tenants access to only one exit since the individual tenant occupant load only required one exit access door? I agree with the plan checker.

As far as the classifications vs. use discussion, which is a departure from the OP but I am guessing has been brought up to verify the occupant load...... IMHO along with various articles and interpretations, occupant load is based on use, not classification. The reason there is a distinction in chapter 3 for small assembly spaces and tenant spaces is to relax the separation requirements between a small space used for assembly and the adjacent occupancies in a separated design. Otherwise, if classified as an A occupancy, every conference room would need separation from the B space they are in.