Despite changes to the code requirements related to nightclubs, tragedies continue to occur. This Decoded article covers some of the door-related considerations.
This post was published in Door Security + Safety
Historically, we have seen many tragedies that have taken place in nightclubs. Often a combination of factors such as locked or blocked egress routes, flammable acoustic foam or decorations, excessive occupant loads, and the use of pyrotechnics have led to a high loss of life. In this month’s Decoded column I will answer the question:
What are some door-related code requirements that can help to improve the safety of nightclubs and similar venues?
Occupant Load and Number of Exits
Typically, these buildings would be considered assembly occupancies, as they are used for gatherings of 50 or more people for the purpose of eating, drinking, and entertainment. The calculated occupant load of a space is based on the area divided by an occupant load factor found in the code. For assembly occupancies without fixed seats, the International Building Code (IBC) lists the following occupant load factors:
- Concentrated (chairs only – not fixed) – 7 net square feet per person
- Standing space – 5 net square feet per person
- Unconcentrated (tables and chairs) – 15 net square feet per person
For example, if a nightclub is divided into an area of 1500 square feet with tables and chairs and 1000 square feet of dance floor that might be considered standing space, the calculation would be:
- Unconcentrated (tables and chairs): 1500 square feet / 15 square feet per person = 100 people
- Standing Space: 1000 square feet / 5 square feet per person = 200 people
- For a total calculated occupant load of 300 people
The number of occupants and the travel distance to each exit determine the number of exits that are required. For an assembly space without fixed seating and an occupant load of 50-500 people, at least two exits are required with a maximum common path of egress travel distance of 75 feet. These exits must be separated from each other by a distance of at least one-half of the maximum overall diagonal dimension of the area, or one-third of this dimension if the building has an automatic sprinkler system.At least three exits or exit access doorways are required by the IBC when the occupant load is 501-1,000 people, and at least four exits are required when the occupant load exceeds 1,000 people. These exits must be arranged a reasonable distance apart, so that if one exit becomes blocked, other exits will be available for use.
If an assembly occupancy has a main exit and an occupant load of more than 300 people, the IBC includes additional requirements related to the exits:
“A building, room or space used for assembly purposes that has an occupant load of greater than 300 and is provided with a main exit, that main exit shall be of sufficient capacity to accommodate not less than one-half of the occupant load, but such capacity shall be not less than the total required capacity of all means of egress leading to the exit. Where the building is classified as a Group A occupancy, the main exit shall front on not less than one street or an unoccupied space of not less than 10 feet (3048 mm) in width that adjoins a street or public way. In a building, room or space used for assembly purposes where there is not a well-defined main exit or where multiple main exits are provided, exits shall be permitted to be distributed around the perimeter of the building provided that the total capacity of egress is not less than 100 percent of the required capacity.”
Egress Capacity
Egress doors must be of sufficient size to accommodate the occupant load. The required egress width of doorways is based on the occupant load served, multiplied by the egress capacity factor. For assembly occupancies, the IBC’s egress capacity factor for doorways is 0.2 inches per occupant if the building does not have an automatic sprinkler system, and 0.15 inches per occupant if the building has a sprinkler system and an emergency voice/alarm communication system.
Doors in a means of egress must also meet the minimum requirements for clear opening size – typically a clear opening width of at least 32 inches is required for each door opening. This is measured with the door in the 90-degree open position, and for single doors, the measurement is taken from the face of the door to the stop on the strike jamb of the frame. For pairs of doors, the clear opening width is measured from the face of the open door to the edge of the other leaf in the closed position, or to the mullion.
With our nightclub example of 300 occupants, the total minimum clear opening width for the egress doors would be:
- Without a sprinkler system: 300 occupants x 0.2 inches/occupant = 60 inches of egress width
- With a sprinkler system and emergency voice/alarm communication system: 300 occupants x 0.15 inches/occupant = 45 inches of egress width
If the nightclub in our example has two egress doors, with each providing the minimum clear opening width of 32 inches required for egress and accessibility, the resulting 64 inches of egress width would accommodate the 300 occupants (with a little room to spare).
Operation of Egress Doors
Egress doors serving an assembly occupancy like a nightclub must be visible, identifiable as doors, and usable by building occupants. Doors must unlatch for egress with one releasing motion, without the use of a key, tool, special knowledge or effort. Exits may not be disguised by curtains, mirrors, or decorations – they must be readily identifiable as doors.
When an egress door serves an assembly space with an occupant load of 50 people or more, the IBC states that the door may only be equipped with a lock or latch if it is panic hardware. There are a couple of exceptions to this rule that allow key-operated deadbolts on the main entrance to a building or tenant space or on a door serving an exterior area where the egress path passes through the interior of the building. For both of these applications the code includes additional requirements.
Most doors must also comply with the accessibility mandates, some of which are included in both the accessibility standards and the model codes. For example, the releasing hardware to unlatch the door must be mounted between 34 inches and 48 inches above the floor, or as further limited by local codes. The hardware must be operable without tight grasping, pinching, or twisting of the wrist, and within the allowable force limitations – this is dependent upon which accessibility standards apply in a particular jurisdiction. There are additional requirements related to opening force, closing speed, clear opening size, threshold height, and door design.
Some doors in nightclubs may be fire door assemblies, designed to deter the passage of smoke and flames to compartmentalize the building and protect the means of egress. These doors must be closed and latched at the time of a fire, and can not be propped open with hooks, wedges, or other mechanical means. NFPA 80 – Standard for Fire Doors and Other Opening Protectives includes detailed requirements for fire door assemblies including limitations on clearance, power door operation, automatic closing devices, hinge details, and more.
Electrified hardware has become much more common in recent decades, and an electrified access control system could be found in a nightclub. If the access control system is one that allows free egress via mechanical use of the door hardware, it is generally acceptable per the model codes as long as the door can be readily opened from the egress side. Other types of electrified hardware systems are considered special locking arrangements, and the adopted codes include sections specific to each type of system. Although a business owner may want to limit egress for security reasons, the model codes require these exits to permit free and immediate egress.
There are many other considerations that may affect the safety of nightclub occupants, but these are the main concerns related to doors. For more information, refer to the codes that have been adopted in the jurisdiction of the building.
You need to login or register to bookmark/favorite this content.
Leave A Comment