Is this legal?

[Melvin Ingall]

 

I rent a workshop within an old factory that has been converted into separate units each with their own key.  My unit has an entry/exit via a communal corridor and also a final fire escape door to the outside world.

Is it legal for one of the other units to have an internal fire door from their unit into mine, there is plenty of room along their corridor wall to have a fire door installed. 

Thank you for any input.