Maximizing rent area has always been the target of developers and architect has to deliver that and also stay in compliance with the building code. One such thing that can give you more space is limiting no of exits. In this case, here we are exploring how large a building can be built with a single exit.
Answer to that question lies in SECTION BC 1021 NUMBER OF EXITS AND CONTINUITY. Under 1021.2 Single exits #4 & #5.
As per #4 building should be less than 4 stories with area not more than 2500 SF, not more than 3 dwelling units per story with windows opening in lawful yard or street, construction shall be Type I or II, Building shall be throughout sprinklered, and staircase shall be enclosed with 2 hrs fire rated walls and extend to roof.
As per #5 it can be an R2 occupancy building with no more than 2000 square feet per story and not more than 6 Story can use the single staircase.
Buildings of Group R-2 occupancy of construction Type I or II not exceeding six stories and not exceeding 2,000 square feet (186 m2) per story.
Building code 2014 NYC
ArchitectNYC 