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.

Strange Observations – Exit Enclosure

Continuing in a series of strange things that I have seen while consulting at hospitals…

This is not corridor, but rather an exit enclosure to a stairwell. There was a construction project in progress and to achieve a negative air pressure in the project area, the contractor cut a hole (twice) in the 2-hour fire-rated barrier for the exit enclosure to run the temporary flex duct to the exhaust fan.

Section 7.1.3.2.1 (10) of the 2012 LSC does not allow penetrations into and through an exit enclosure for this purpose, even on a temporary basis.

If you’re asking what the hospital should have done if this was their only option to create negative air for the project, I would say they could have set-up a HEPA filter negative air machine inside the project area, and discharge the air from the HEPA blower to an adjacent corridor. Not the best solution, but one that is far better than making penetrations into the exit enclosure.

There is also the issue of headroom which must be at least 7-foot 6-inches, according to section 7.1.5.1.