Our office relocated into such a building.  It is a three-story brick
commercial building on Main Street, that is land-locked with only the
street frontage for access or egress.  The city building department
required a variance be granted by the local Building Board of Appeals in
order to be granted a building permit and certificate of occupancy.
Based on size limiting occupancy and installation of full fire
supression, the appeal was granted.  Whew!

There are times I think about my exit strategy from the third floor, and
it is no accident that I sit near the windows.  Sometimes people prop
open the doors on the 1st and 2nd floors, and I remind them that is a
no-no.  I intend to get one of those ladders you can hook over a window
sill, although I could jump and slide off the awning...

So, anyway, this issue is dealt with in Ann Arbor, MI by conventional
use of BOCA codes and the local appeal process.

Ilene R. Tyler, AIA