Do all units require two egresses? New Jersey Multi-Family

[Chris T.]

I'm currently looking into a buying a multifamily property in New Jersey. It was once a two family, converted to 3 units many years ago. According to the owner it's been grand fathered in (still need to find out what that means) and he has no issues with zoning.

One thing I did notice is that a unit on the 2nd floor only has a single egress, just the front door on the 1st floor. 

Is this legal?

Only way I can see this being allowed is since it's only a 2 story residence?

Any thoughts or insights would be appreciated.