When does NFPA allow multi-story buildings to have one exit stairwell?

by Nils Deacon, Manager, Inspections and Rating Services

Buildings four stories in height or less are permitted by NFPA (the National Fire Protection Association) to have one exit stairwell, under certain conditions.

The most effective feature is a monitored automatic sprinkler system approved by the authority having jurisdiction or AHJ.

Another important feature would be having no more than four dwelling units per story. Travel distance from the apartment unit entry door to a fire exit should not exceed 35 feet.

The exit stairwell should be completely enclosed, separated structually from the rest of the building and include one-hour fire resistant assemblies, and self closing one-hour fire resistant fire doors. nfpa.org

DISCLAIMER: This information reflects the interpretation of MSO, Inc. with regard to NFPA Standards and Codes and other code sources. It does not represent these code’s official position on the items discussed.

Enclosed stairwell