Small Assembly Occupancy

[LGreene]

I just finished an article about small assembly spaces for my monthly column in Doors & Hardware. I can't quite figure out exactly how an AHJ would calculate the occupant load - basically, which occupant load factor to use. I included a couple of photos in the article of college classrooms where various factors could be used depending on an AHJ's interpretation. Can you give me any insight? The article is here:

http://idighardware.com/2016/06/decoded-small-assembly-occupancies/

 

[JBI]

Well, you inadvertently flipped the factor near the end... "There’s a fine line between an unconcentrated assembly space (20 net square feet per person) and an educational classroom (15 net square feet per person)".
Beyond that, the means of egress would need to accommodate the highest occupant load that is expected from the space. So a College classroom, which IS an Assembly USE of the space would need to accommodate the highest anticipated occupant load.
Even without fixed seating, the 15 s.f. per person would usually be most appropriate as student desks are akin to 'tables and chairs' IMHO. IF that College uses, or intends to use chairs only, then the 7 s.f. per person would be appropriate.
Notice I did not say Assembly OCCUPANCY, but Assembly USE. Occupancy class and use of space, as you point out in the article, can be and often are different beasts. Code Officials need to understand the difference, no matter how subtle it may be.
IF the intended use of the space changes, then the MOE should be re-evaluated as part of the process.

BTW, NYS Education Law provides a second level of regulation that goes above and beyond 'the Code'. One item that is well addressed is egress.

 

[cda]

Kind of depends on what is submitted on furniture fixture plan.

Can be by factor, fixed seating, or what the reviewer wants to assign.

Can also post multiple occupant load number, with various set ups of the room.

Clear as mud, sometimes just has to be case by case.

 

[LGreene]

Well, you inadvertently flipped the factor near the end... "There’s a fine line between an unconcentrated assembly space (20 net square feet per person) and an educational classroom (15 net square feet per person)".

Oops! Thanks - I fixed that. I'll check out the NYS resource to see if there's anything that can help to clarify this.

 

[Paul Sweet]

In Virginia we typically keep the 20 SF per person even for large classrooms. For classrooms with a folding partition between them we will often use 20 SF per person with the partition closed, and 15 SF per person with the partition open. 7 SF per person is typically for rooms whose primary use is assembly.

If you arbitrarily force the use of a denser occupant load than the room's typical use, it adds plumbing fixtures and causes the HVAC system to be oversized.