Interesting question. As the linked discussion below says, the answer isn't clear. Perhaps an inspector would say the finished area needs its own egress.

There are no basement egress requirements here, so I haven't had to deal with this issue.

Here is a link that might be useful: Egress Solutions for Basement Living Space

Well, I guess in theory if left a 4 ' wide opening from finished space to unfinished that might satisfy the code...another reason removable bifolds may be the way to go...

This sounds like a gray area that might be subject to interpretation by the AHJ. A quick call to your local building department might save some headaches down the road.

Not sure if this helps, but the link below is a snapshot from the requirements in my area.

bottom line we have a 36" steel door exiting up 6 steps to a bilko door.Essentially I want to enclose this door in its own room. 4' Bifolds will separate this room from the main area....I would think this has to be up to code...ifnot I could remove the bifolds....?

In most areas I've lived, the code requirements for basement egress are based on use of space. Direct egress is required only from rooms in which people will be sleeping.

It wouldn't be an issue in my town as long as the room could not be used as a bedroom (no closet allowed).