duplexing 2nd floor unit into attic

[Tyler Dunkel]

Hi,

I have a building which has a finished attic space on the "3rd" floor. This space only has one egress from the back stairs. I want to create a duplex up unit by combining the second floor and 3rd floor into one unit. Would I need to add a second egress to the 3rd floor for this to be compliant or would the one egress (from the back stairs) be sufficient? 

Thanks!