How many exits a space needs, and where they go, is set by IBC 1006–1007. Most spaces and stories need at least two exits, rising to three at higher occupant loads and four above 1,000. Section 1006 also defines the single-exit conditions — small spaces under specific occupant-load and travel-distance thresholds that are permitted one exit.
Arrangement matters as much as number: where two exits are required, they must be remote from each other — separated by at least half the diagonal of the space (reduced to one-third in sprinklered buildings) — so a single fire can't block both.
The common mistake is two exits placed too close together, failing the remoteness rule, or relying on a single exit where the occupant load or travel distance actually requires two. Reviewers count required exits against occupant load and check the separation distance on the plan — remoteness failures are common and usually force relocating a door or stair.
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.