I need help badly on a dwelling unit located in Chicago, IL

A geneal contractor has told me: If a rental dwelling unit is under 800 sq feet it only needs one doorway to be used as both an entrance and an exit out of the dwelling unit. but when they exit the dwelling unit they need two exits out of the building.

I always thought you needed 2 exits out of the unit.

I appreciate all responses, I Have not been able to get a response from the city or any help on the internet..

Thank you very much
Carmen Flores