Yikes
SAWHORSE
Amber, I know this isn't the original question you asked, but it sounds like you are trying to send the entire occupant load of 4 upper-story apartments down a single exterior exit stair, and that stair is the only stair serving those 4 apartments.
I think the IBC limits the upper story R-1 apartment area served by single stair to 10 occupants (Table 1006.2.1), which is max. 2000 SF of aggregate apartment space (Table 1004.1.2).
In other words, if your 4 apartments average greater than 500 SF of area , then a single exit stair won't meet code (regardless of travel distance issues).
I think the IBC limits the upper story R-1 apartment area served by single stair to 10 occupants (Table 1006.2.1), which is max. 2000 SF of aggregate apartment space (Table 1004.1.2).
In other words, if your 4 apartments average greater than 500 SF of area , then a single exit stair won't meet code (regardless of travel distance issues).