- 708.14.1 Elevator lobby.
- 1. Enclosed elevator lobbies are not required at the street floor, provided the entire street floor is equipped with an automatic sprinkler system in accordance with Section 903.3.1.1.
- 2. Elevators not required to be located in a shaft in accordance with Section 708.2 are not required to have enclosed elevator lobbies.
- 3. Enclosed elevator lobbies are not required where additional doors are provided at the hoistway opening in accordance with Section 3002.6. Such doors shall be tested in accordance with UL 1784 without an artificial bottom seal.
- 4.1. Group I-2 occupancies;
- 4.2. Group I-3 occupancies; and
- 4.3. High-rise buildings.
- 5. Smoke partitions shall be permitted in lieu of fire partitions to separate the elevator lobby at each floor where the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2. In addition to the requirements in Section 711 for smoke partitions, doors protecting openings in the smoke partitions shall also comply with Sections 711.5.2, 711.5.3, and 715.4.8 and duct penetrations of the smoke partitions shall be protected as required for corridors in accordance with Section 7220.127.116.11.
- 6. Enclosed elevator lobbies are not required where the elevator hoistway is pressurized in accordance with Section 708.14.2.
- 7. Enclosed elevator lobbies are not required where the elevator serves only open parking garages in accordance with Section 406.3.
An elevator lobby or one of its alternatives found in the exceptions to Section 708.14.1 is required whenever an elevator shaft connects more than three stories. Elevator shafts often constitute the largest vertical shaft in multiple-story buildings. Hoistways have the potential for accumulating and spreading hot smoke and gases from a fire to other stories in a building. The chimney or stack effect helps with the upward spread of the products of combustion. It is recognized that smoke is a major factor in fire deaths and smoke often migrates to areas remote from the source of the fire. Due to the typical operation and movement of the hoistway doors, they generally cannot provide the level of reduced air leakage that is required to reduce the spread of smoke.
Chapter 7 provisions in general address the isolation or compartmentation of fire areas, rooms and stories, which prohibits the growth of fires. Analyses of fires in multiple-story buildings have documented the movement of smoke to upper levels. In the 1980 fire at the MGM Grand Hotel in Las Vegas, 70 of the 84 deaths occupied the 14th to 24th floors, although the fire was on the first level. The Johnson City Retirement fire in 1989 also had a fire originating on the first level with all but two of the 16 fatalities occurring on the upper floors due to smoke movement via vertical shafts that included the elevator hoistway.
The elevator lobby requirement further isolates the fire-resistance-rated elevator shaft enclosures.
The lobby enclosure walls must separate the elevator hoistway doors from the rest of the building by 1-hour fire-resistance-rated partitions constructed for fire partitions. As a point of difference, the chute access rooms required fire barrier construction, whereas, the elevator lobby requirements are for fire partition construction. The elevator lobby separation does not require a horizontal assembly for the floor/ceiling, either, as does a chute access room. But on a positive note, this section references Sections 715.4.3 and 718.104.22.168 for door openings and duct openings. Therefore, the elevator lobby separation requires the 20-minute doors to be smoke and draft control doors (see Section 715.4.3) and also requires duct penetrations to have smoke and fire dampers (see Section 722.214.171.124) unless exempted by those sections. The purpose of the special opening protectives in the elevator lobby enclosures is to delay or prevent the vertical spread of smoke to other floors through the hoistway doors and the shaft.
This section also requires at least one means of egress from the elevator lobby enclosure. Multiple-story buildings often have security concerns that are solved by controlled access from elevator lobbies to the remainder of the floor. Section 708.14.1 clearly establishes that every elevator lobby shall have at least one means of egress ensuring that no occupant in a lobby is left isolated from escape. While this section requires one door from the elevator lobby, every room or space on the floor including the lobby must have access to the required number of exits (usually two) on that story without traveling through tenant spaces. In other words, once the occupant leaves the elevator lobby, he or she must have access to two exits. Egress through elevator lobbies from corridors on both sides is also allowed.
Two questions often arise. One, can a space have its only exit access path through an elevator lobby? The answer is yes, if it meets all the other egress requirements. Second, can an exit enclosure open into an elevator lobby? The answer is yes. An elevator lobby is a normally occupied space in the same manner that a corridor is a normally occupied space. Of course, the elevator hoistway doors can never open into an exit enclosure.
There are seven exceptions that eliminate the requirement for enclosed elevator lobbies or modify the enclosure.
Exception 1 removes the requirement for an enclosed elevator lobby on the street floor of a building when the entire street floor is provided with automatic sprinkler protection. The exception is notable in that it is not conditioned upon the entire building being sprinklered but just the first floor. All fully sprinklered buildings would be relieved of the elevator lobby requirements on the first story.
Exception 2 eliminates the requirement for enclosed elevator lobbies if the elevator is not required to be enclosed in a fire-resistance-rated shaft. Exception 14 to Section 708.2 exempts elevator hoistways in buildings exclusively used for parking. Although Exception 5 is for floor openings in an atrium, it is often considered to allow elevator hoistways located entirely within the atrium to be unenclosed. If an elevator is not required to have a fire-resistance-rated enclosure, it serves no purpose to require a fire-resistance-rated elevator lobby enclosure.
Exception 3 eliminates the need for a lobby area, but still requires the additional layer of fire resistance and smoke control. Doors, in addition to the normal hoistway door, are provided in front of the hoistway opening. These doors or door must meet the following two requirements:
1. They must be easily opened in accordance with Section 3002.6. This ensures that if the door or doors do close that they can be opened by someone who arrives at that level on the elevator, such as fire department personnel. This is particularly important if the doors are horizontal power-operated doors, such as those in Section 1008.1.4.3. Section 3002.6 states that the doors shall be readily openable from the car side without a key, tool, special knowledge or effort.
2. Additional door or doors must be tested in accordance with UL 1784. This test is titled "Air Leakage Tests of Door Assemblies." This test does not provide a fire-resistance rating for the door. This test has no failure criteria as it only measures the leakage rate. The leakage rate for smoke and draft control doors in Section 7126.96.36.199 is a maximum of 3 cubic feet per minute per square foot (0.0014 m3/s) of door opening at 0.10 inch of water column pressure (0.02 kPa). It is assumed that they must meet the leakage rate requirements in Section 7188.8.131.52, and they must be identified as smoke and draft control doors in accordance with Section 7184.108.40.206.
Exception 4 applies to other than Group I-2, Group I-3 and high-rise buildings. An elevator lobby is not required if the building is protected by an NFPA 13 or NFPA 13R sprinkler system. This recognizes the effectiveness of sprinkler systems in controlling the spread of smoke. This exception does not apply to buildings with a floor level over 75 feet (22 860 mm) above the lowest level of fire department vehicle access, nor does this exception apply to Group I-2 and I-3 regardless of height.
Exception 5 still requires an elevator lobby. This exception requires either an NFPA 13 or 13R sprinkler system. This exception allows nonfire-resistance-rated smoke partitions to enclose the lobby in lieu of the normal 1-hour fire-resistance-rated fire partitions. Door openings in the lobby enclosure must still meet the air leakage rate in Section 711.5.2 and must be self-closing or automatic closing. Duct penetrations through the smoke partitions must also be provided with smoke dampers in accordance with the referenced Section 7220.127.116.11. This is not much of an exception. Use Exception 5 for Group I-2, I-3 and high-rise buildings; otherwise use Exception 4.
In Exception 6, elevator hoistway pressurization can be used in lieu of elevator lobbies in all buildings regardless of height. This is similar to pressurization of stair enclosures, which is used in lieu of smokeproof enclosures for stairs in Section 909.20.5. The hoistway pressurization requirements are in Section 708.14.2.
Exception 7 is similar to Exception 14 in Section 708.2. parking tiers are open between levels by necessity anyway. Elevators used exclusively to serve only parking levels do not need enclosures, nor do they need lobby separation.