Fire Safety, Life Safety, and Egress Design
What this domain tests
This domain tests the means-of-egress chain: exit access, exit, and exit discharge. You must calculate occupant load, width, number of exits, travel distance, common path, and dead ends, then check door hardware and swing.
Core rules and concepts
- Occupant load factors include 100 gross sf per occupant for business, 60 gross for mercantile, 20 net for classrooms, 15 net for unconcentrated assembly, and 7 net for concentrated assembly.
- Egress width is 0.2 in per occupant in sprinklered buildings and 0.3 in unsprinklered; stairs use 0.3 in sprinklered and 0.4 in unsprinklered. Never reduce a door below 32 in clear.
- Corridors are 44 in where serving 50 or more occupants and 36 in otherwise. Doors swing in the direction of egress at 50 occupants; panic hardware applies at 100 in assembly and other high-hazard cases.
- Travel distance for Group B is commonly 200 ft unsprinklered and 300 ft sprinklered. Common path and dead-end limits are separate checks.
Worked example
A sprinklered 12,000 sf mercantile tenant: 12,000 / 60 = 200 occupants. Width = 200 x 0.2 = 40 in. Two 32 in clear doors provide 64 in, so width is satisfied; stairs would need 200 x 0.3 = 60 in. Confirm travel distance to the nearest exit is within the mercantile limit and that the common path is within its separate cap.
Traps
Using net factors for gross areas; forgetting that stair width differs from door width; measuring travel distance around furniture instead of the actual path; and ignoring door swing conflicts at rated corridors.