Do vestibules at the entrance of buildings require mechanical ventilation? As those spaces have lots of air exchange with the outdoors when people enter or leave the building, it seems to me that ventilation is not necessary.

Second question:
Do interior stairs require ventilation? Should we consider stairs as corridors?

I know spaces not intended for common use do not need ventilation. There are however, some stairs that are called emergency stairs but used daily.

Any opinions?