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NFPA 101 14.2.5.4 - net or gross area?

Tim Mailloux

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Feb 12, 2018
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Hartford CT
Looking for clarification on NFPA 101 14.2.5.4 which requires any room larger than 1000sf OR with more than 50 occupants have 2 means of egress. With regards to the 1000sf threshold, is that net or gross floor area? If its net floor area I can deduct things like built in casework to reduce the area and possibly get under the 1000sf threshold. If its gross floor area than I am out of luck.

14.2.5.4 Every room or space larger than 1000 ft2 (93 m2) or with an occupant load of more than 50 persons shall comply with the following:
(1) The room or space shall have a minimum of two exit access doors.
(2) The doors required by 14.2.5.4(1) shall provide access to separate exits.
(3) The doors required by 14.2.5.4(1) shall be permitted to open onto a common corridor, provided that such corridor leads to separate exits located in opposite directions.

For Context we are designing some large high school science lab classrooms approximately 1300sf in size with a substantial amount of built in casework and countertops around the perimeter of the classrooms. For the occupant load calculations for these rooms, I can use the net floor area which does not include the built in casework and have an occupant load under 50 people. But as 14.2.5.4 doesn’t specify gross or net floor area my inclination of to play it safe and add a second means of egress from each one of these rooms as they are over 1000 sf.
 
just found a note in the NFPA handbook to the definition of the term gross floor area which states where the term floor area is used, it should be understood to be gross floor area, unless otherwise specified.
 
From the NFPA 101, Annex A, Explanatory Material:

A.3.3.22.2.2 Gross Floor Area.​

Where the term floor area is used, it should be understood to be gross floor area, unless otherwise specified.
I found this shortly after I submitted my original post and added a 2nd post with this same info.
 
Are you using 20 SF for classrooms or 50 SF for shops laboratories, vocational rooms for an OLF? Both under educational use. Sure feels like a lab.
 
Are you using 20 SF for classrooms or 50 SF for shops laboratories, vocational rooms for an OLF? Both under educational use. Sure feels like a lab.
either at 20 for classrooms or 50 for labs, my occupant load isn't the driving factor in these large rooms as I am allowed to use the Net floor area for occupant load calculations and I can deduct the casework. Its the 1000 sf area threshold thats triggering the two means of egress which there does not appear to be any way around as that appears to be 1000 gross sf per the NFPA annex clarification.


14.2.5.4 Every room or space larger than 1000 ft2 (93 m2) or with an occupant load of more than 50 persons shall comply with the following:
 
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