Egress has to work for people who can't use stairs, and IBC 1009 handles it. Each required means of egress must include a compliant accessible route, and where accessible egress relies on stairs or elevators, areas of refuge — protected spaces where someone can wait for assisted rescue — come into play, along with two-way communication systems at those locations.
A major exception: buildings equipped throughout with an automatic sprinkler system generally aren't required to provide areas of refuge, which is why sprinklering often simplifies accessible egress design.
The common mistake is providing an accessible entrance and route but no compliant accessible egress from upper floors — or omitting the area of refuge and two-way communication in a non-sprinklered building. Reviewers confirm the number of accessible means of egress matches required exits, and check for areas of refuge (or the sprinkler exception) plus the communication provisions where they apply.
This guide describes the model code for general understanding and is not a substitute for the adopted code and amendments enforced by your local authority having jurisdiction. Verify all figures against your jurisdiction's codes of record.