Triplex, Single Exit, R-2 Occupancy, with bi-level 3rd and 4th floor unit

[naveph]

Hi I have a 4 story townhome with 3 units up for permit review. The top two stories are one unit that egress on the 3rd floor. We thought we could use exception 5 since the unit exits directly to exit enclosure which exits directly outside. We got a comment back from the reviewer that this condition doesn’t meet this exception. We have done this same configuration under the 2009 IBC based on occupant loads under 20 , but the 2018 verbiage has changed. Does anyone have any recommendations how to accommodate this scenario with one exit aside from a mezzanine?