Usable Space in an Exit Enclosure

Q: We have an enclosed room in an exit enclosure that is being used as a classroom. I’m using NFPA 101, 2015 LSC, section 7.2.2.5.3 Usable Space. Is this a code compliant arrangement?

A: It depends…If the enclosed room is separated from the exit enclosure with fire-rated construction equal to the stairwell, and if the enclosed space does not interfere in any way with egress, and the access to the enclosed space is not from the stairwell itself…. Then I would say it is permitted.