How can it be in almost any way a mezzanine? What exiting Place would this proposed "mezzanine" be in? Could it be in between the floor and the ceiling of the present Area? On condition that the OP indicated this space is 3,088sf and that other portions already have elevators, https://drum-handling91454.ambien-blog.com/45055382/5-tips-about-mezzanine-barriers-you-can-use-today