FEMA 453 Design Guidance for Shelters and Safe Rooms

exit is commonly defined as a protected path of travel to the exit
discharge (NFPA 101, 2006). The stairways in a high-rise building
commonly meet the definition of an exit. In general, the exit is
intended to provide a continuous, unobstructed path to the exterior
or to another area that is considered safe. Most codes require
that exits discharge directly to the outside. Some codes, such as
NFPA 101, permit up to half of the exits to discharge within the
building, given that certain provisions are met.
There is no universally accepted standard on emergency evacuation.
Design considerations for high-rise buildings relative to
these two options involve several aspects, including design of
means of egress, the structure, and active fire protection systems
(e.g., detection and alarm, suppression, and smoke management).
Many local jurisdictions, through their fire department
public education programs, have developed comprehensive and
successful evacuation planning models but, unless they are locally
adopted, there is no legal mandate to exercise the plans. Seattle,
Phoenix, Houston, and Portland, Oregon, are among the cities
that have developed comprehensive programs.
The NIST life safety, egress, and emergency response findings
provide valuable lessons learned for future shelter evacuation
design. Currently, building fire protection is based on a four-level
hierarchical strategy comprising alarm and detection, suppression
(sprinklers and firefighting), compartmentation, and passive protection
of the structure.
m Manual stations and detectors are typically used to activate
fire alarms and notify building occupants and emergency
services.
m Sprinklers are designed to control small and medium fires
and to prevent fire spread beyond the typical water supply
design area of about 1,500 square feet.
m Compartmentation mitigates the horizontal spread of more
severe but less frequent fires and typically requires fire-rated
design considerations
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