Generally, a higher hazard requires more changes than a same hazard or lower hazard - The trick with the IEBC is to use one of three methods _ Prescriptive (Chapter 4), Alteration level (1-III, change of occupancy, addition), or the performance portion of the code. This is the designer's job to convey which method they are choosing for compliance.
We recently had a building where the electrical room was being modified to provide for enclosed stairways - however, it was discovered that the primary internet fiber line ran across the proposed location for the new door - The designer was able to use the performance code to circumvent prescriptive means of the code to allow access to the electrical room thru the stairway - a little unorthodox but the life safety and means of egress scores were sufficient even with the ding caused by the stairway SNAFU.
Not a great design, however the changes being provided are bringing the existing four story community college building more code compliant than before. - In other words, the stairway dings still scored high enough that one of four stairways did not have to be fire rated or enclosed. (One of the few times that the performance portion of the IEBC was beneficial to the architect and to the college.)