1. In all occupancies, other than Group H and I occupancies,
a stairway is not required to be enclosed when the stairway
serves an occupant load of less than 10 and the
stairway complies with either Item 1.1 or 1.2. In all
cases, the maximum number of connecting open stories shall
not exceed two.
1.1. The stairway
is open to not more than one story above the story at
the level of exit discharge; or
1.2. The stairway
is open to not more than one story below the story at
the level of exit discharge.
2.
Exits in buildings of Group A-5 where all portions of
the means of egress are essentially open to the outside
need not be enclosed.
3. Stairways serving and contained within a single
residential dwelling unit or sleeping unit in Group R-1,
R-2 or R-3 occupancies are not required to be enclosed.
4. Stairways that are not a required means of egress
element are not required to be enclosed where such stairways
comply with Section 707.2.
5. Stairways in open parking structures that serve
only the parking structure are not required to be enclosed.
6. Stairways in Group 1-3 occupancies, as provided
for in Section 408.3.6, are
not required to be enclosed.
7. Means of egress stairways as required by Section
410.5.3 are not required to be enclosed.
8. In other than Group H and I occupancies, a maximum
of 50 percent of egress stairways serving one adjacent
floor are not required to be enclosed, provided at least
two means of egress are provided from both floors served
by the unenclosed stairways. Any two such interconnected
floors shall not be open to other floors. Unenclosed exit
stairways shall be remotely located as required in Section
1015.2.
9. In other than Group H and I occupancies, interior
egress stairways serving only the first and second stories
of a building equipped throughout with an automatic sprinkler
system in accordance with Section
903.3.1.1 are not required to be enclosed, provided
at least two means of egress are provided from both floors
served by the unenclosed stairways. Such interconnected
stories shall not be open to other stories. Unenclosed
exit stairways shall be remotely located as required in
Section 1015.2.
1020.1.1 Openings and penetrations. Exit enclosure opening
protectives shall be in accordance with the requirements
of Section 715.
Except
as permitted in Section 402.4.6,
openings in exit enclosures other than unprotected exterior
openings shall be limited to those necessary for exit access
to the enclosure from normally occupied spaces and for egress
from the enclosure.
Where
interior exit enclosures are extended to the exterior of
a building by an exit passageway, the door assembly from
the exit enclosure to the exit passageway shall be protected
by a fire door assembly conforming to the requirements in
Section 715.4. Fire door assemblies
in exit enclosures shall comply with Section
715.4.4. Elevators shall not open into an exit enclosure.
1020.1.2 Penetrations. Penetrations into and openings
through an exit enclosure are prohibited except for required
exit doors, equipment and ductwork necessary for independent
pressurization, sprinkler piping, standpipes, electrical
raceway for fire department communication systems and electrical
raceway serving the exit enclosure and terminating at a
steel box not exceeding 16 square inches (0.010 m2).
Such penetrations shall be protected in accordance with
Section 712. There shall be no penetrations
or communication openings, whether protected or not, between
adjacent exit enclosures.
1020.1.3 Ventilation. Equipment and ductwork for exit
enclosure ventilation as permitted by Section 1020.1.2 shall
comply with one of the following items:
1. Such equipment and ductwork shall be located exterior
to the building and shall be directly connected to the
exit enclosure by ductwork enclosed in construction as
required for shafts.
2. Where such equipment and ductwork is located within
the exit enclosure, the intake air shall be taken directly
from the outdoors and the exhaust air shall be discharged
directly to the outdoors, or such air shall be conveyed
through ducts enclosed in construction as required for
shafts.
3. Where located within the building, such equipment and
ductwork shall be separated from the remainder of the
building, including other mechanical equipment, with construction
as required for shafts.
In
each case, openings into the fire-resistance-rated construction
shall be limited to those needed for maintenance and operation
and shall be protected by opening protectives in accordance
with Section 715 for shaft enclosures.
Exit enclosure ventilation systems shall be independent
of other building ventilation systems.
1020.1.4 Exit enclosure exterior walls. Exterior walls
of an exit enclosure shall comply with the requirements
of Section 704 for exterior walls.
Where non-rated walls or unprotected openings enclose the
exterior of the stairway and the walls or openings are exposed
by other parts of the building at an angle of less than
180 degrees (3.14 rad), the building exterior walls within
10 feet (3048 mm) horizontally of a non-rated wall or unprotected
opening shall have a fire-resistance rating of not less
than 1 hour. Openings within such exterior walls shall be
protected by opening protectives having a fire protection
rating of not less than 3/4 hour.
This construction shall extend vertically from the ground
to a point 10 feet (3048 mm) above the topmost landing of
the stairway or to the roof line, whichever is lower.
1020.1.5 Discharge identification
barrier. A stairway in an exit enclosure shall not continue
below the level of exit discharge unless an approved barrier
is provided at the level of exit discharge to prevent persons
from unintentionally continuing into levels below. Directional
exit signs shall be provided as specified in Section
1011.
1020.1.6 Stairway floor
number signs. A sign shall be provided at each floor
landing in interior exit enclosures connecting more than
three stories designating the floor level, the terminus
of the top and bottom of the stair enclosure and the identification
of the stair. The signage shall also state the story of,
and the direction to the exit discharge and the availability
of roof access from the stairway for the fire department.
The sign shall be located 5 feet (1524 mm) above the floor
landing in a position that is readily visible when the doors
are in the open and closed positions.
1020.1.7 Smokeproof enclosures.
In buildings required to comply with Section
403 or 405, each of the exits
of a building that serves stories where the floor surface
is located more than 75 feet (22 860 mm) above the lowest
level of fire department vehicle access or more than 30
feet (9144 mm) below the level of exit discharge serving
such floor levels shall be a smokeproof enclosure or pressurized
stairway in accordance with Section
909.20.
1020.1.7.1 Enclosure exit.
A smokeproof enclosure or pressurized stairway shall
exit into a public way or into an exit passageway, yard
or open space having direct access to a public way. The
exit passageway shall be without other openings and shall
be separated from the remainder of the building by 2-hour
fire-resistance-rated construction.