During permit plan review, the AHJ challenged the provision of NFPA 101 which states that “outside stairs shall be arranged to restrict the accumulation of smoke”. Due to the unique architecture of these buildings, the AHJ wanted confirmation that the arrangement of the exit access balconies openings would support natural smoke movement to maintain safe egress.
We performed fire modeling to simulate likely fire scenarios and smoke movement from the open exit access breezeways. We determined that the building was provided with sufficient openings to maintain tenability throughout the means of egress.
Fire modeling analysis supported the open balcony arrangement without any design changes
Resolved AHJ comment without providing enclosed stairs
Assisted the Client in avoiding significant project delays and cost overruns
NFPA 101 Section 220.127.116.11
Outside Stair 3.3.265.2 (NFPA 101)
Outside Stair 50% open