Door lock

Swinging Egress Door Operation: Permissible Egress Door Locking Arrangements

Every component in the means of egress (an unobstructed route from any point in a building to a public way) must be operable by, and under the control of, the occupants attempting egress. One of the biggest obstacles a person can encounter, preventing them from free egress, is a locked door. Approaching a noncompliant locked door unexpectedly and without the means necessary to operate it is an example of when egress becomes outside of an occupant’s control. This can hinder evacuation time and prevent occupants from getting to their point of safety.  I recently wrote about the basics of swinging egress door operation, and we will continue that discussion here by focusing on some of the specifics of permissible door locking arrangements, so that we can better understand if door locking is permitted and what is required to do it safely.

An unfortunate increase in hostile events, and similar threats has also increased the presence of security features on door assemblies within the means of egress to prevent unwanted entry. This added security, particularly where door assemblies to exit stairs and main egress routes are involved, could be disastrous in the event of a fire or other emergency. The provisions of NFPA 101 Life Safety Code are aimed at preventing locked door assemblies in means of egress in the event of fire. The Code has attempted to balance this objective of free and unobstructed egress while also maintaining features that are essential to security within the building.

Where locked doors are permitted, additional requirements are often mandated to achieve an equivalent level of life safety as would be provided if the means of egress system were fully under the control of the building occupants and did not contain locked doors. For example, in health care occupancies locked door assemblies are permitted if it is necessary for specialized protective measures or the clinical needs of the patients.  In this case, there are a number of additional requirements that need to be met, that include requiring staff to carry the keys needed to unlock those door assemblies at all times.

DOOR OPERATION

To achieve free and unobstructed egress, there are several general concepts to consider in all buildings regarding swinging egress door locking and latching:

  1. Door leaves must be arranged to be opened readily from the egress side whenever the building is occupied.
    This requirement is consistent with the concept that all components in the means of egress must be under the control of the occupants. When an occupant approaches a door within their means of egress, they cannot be met with unexpected obstacles outside of their control that would prevent them from passing through the opening. The use of key locks or complex devices, such as door handles or latches covered with glass that must be broken, is prohibited.
  2. Locks and latches cannot require the use of a key, a tool, or special knowledge or effort to operate from the egress side.
    Locks that require the use of a key, a tool, or special knowledge or effort to open the door leaf from the egress side are prohibited unless meeting one of the recognized locking arrangements discussed later in this blog. It cannot be assumed that an occupant has access to the key, or device that is required to operate the door from the egress side. It takes much longer to operate a door that has been equipped with additional locking/unlatching components which is time that an occupant may not have available to them when trying to evacuate a building during an emergency. This also prohibits doors being locked via a keypad or card reader on the egress side without additional protection measures. To prevent unauthorized entry, door assemblies are generally permitted to be locked from the non-egress side.
  3. All locks, latches, and all other fastening devices on a door leaf must be provided with a releasing device that has an obvious method of operation and that is readily operated under all lighting conditions.
    Examples of conventional devices used release locks and latches include knobs, levers, and bars. Unfamiliar methods of operation, such as a blow to break glass, would not be acceptable. Switches integral to traditional doorknobs, lever handles, or bars, and that interrupt the power supply to an electrical lock are permitted if they are affixed to the door leaf. Where a latch or other similar device is provided, the method of operation of its releasing device must be obvious, even in the dark. The method of release must be one that is familiar to the average person.  Panic and fire exit hardware is another example of hardware that has an obvious method of operation and is readily operated under all lighting conditions (While not required for all situations, it meets the other conditions we talk about here as well.)
  4. The operation of the releasing mechanism must release all latching and all locking devices of the door leaf with not more than one motion in a single linear or rotational direction.

An example of a releasing motion in a single linear direction could be pushing on a panic bar to release the locking/latching hardware to allow a door to be opened. An example of a releasing motion in a single rotational direction would be turning a lever-operated handle of a door lockset in either a clockwise direction or a counterclockwise direction (but not both directions) to unlock/unlatch the door. Multiple motions to unlock or unlatch a door, again, takes time and can delay a person from getting to their point of safety.  There are several situations that do permit additional motions, such as in residential occupancies and school and daycare classrooms. These are permitted to balance unique security needs as well as to recognize situations where occupants are, themselves, locking the doors (such as a hotels and apartments) and the operation of the door during egress is under their control.


Swinging exit door that meets all door operational criteria

PERMISSIBLE DOOR LOCKING ARRANGEMENTS

There are situations where a locked door within the means of egress is necessary and permitted.  But to do this, additional measures must be in place to ensure that, while meeting security needs, the locked door does not become an obstacle to a person’s egress travel and prevent them from getting to their point of safety quickly and efficiently.  When providing egress door locking arrangements, pay careful attention to the details for how to achieve the door locking safely and when and where these locking arrangements are permitted.It is not a one size fits all installation. Many permissions to lock doors are dependent on the type of occupancy and the location of the door within the building.

Key-Operated Locks – Doors equipped with key-operated locks, such as a deadbolt, are an exception to the rule that locks and latches cannot require the use of a key, a tool, or special knowledge or effort to operate from the egress side to open. Doors equipped with key-operated locks may be found on the exterior of a store or office where added security is required after-hours, for example.

Stairway Reentry – Some stair enclosure door assemblies are permitted to be locked to prevent reentry to the building on selected floors. This arrangement provides flexibility in buildings that, perhaps for security reasons, do not want occupants to enter certain spaces of the building, while at the same time ensuring that one can reenter the building if necessary, without having to travel up or down too many flights of stairs.

Delayed egress electrical locking systems. This type of locking system delays egress through the door by preventing the door leaf from opening for 15 or 30 seconds. Doors with this type of locking system are commonly installed where there are concerns for internal security, such as theft from a store. Delayed-egress electrical locking systems might also be installed where occupants might benefit by being protected from their actions, such as a specialized patient care floor in a nursing home.


Swinging egress door with a delayed egress electrical locking system

Sensor-release of electrical locking systems. Doors with this locking arrangement are intended to be locked against access from the outside of the building and require a magnetic card or similar tool for entry. In order to provide free egress a sensor is provided on the egress since to electrically unlock the door leaf in the direction of egress when an person approaching the door is detected. Where the sensor fails, a manual release device, such as a push button, is also provided as a backup.

Elevator lobby exit access door locking. This locking arrangement permits door assemblies that separate the elevator lobby from the exit access to be electrically locked. The locked door between the elevator lobby or landing and the exit may be an obstruction to egress but with the twelve criteria that must be met in order to apply this locking arrangement, it balances the security need with safety of the occupants. The criteria blend a host of provisions for fire detection and alarm systems, sprinkler systems, occupant and staff two-way communication systems, and automatic lock release systems

Door hardware release of electrically locked egress door assemblies. Doors utilizing this locking arrangement are locked with an approved electrical locking system that is released by door hardware that is affixed to the door leaf itself..  The door leaf is typically held locked to its frame with an electromagnet. The biggest difference between this type of locking arrangement and that described in condition (2) is the location of the releasing hardware (affixed to the door leaf vs sensor).Doors with this arrangement operate very similarly to a traditional door assembly.


Electrically locked swinging egress door with door hardware release

CONCLUSION

Leaving a building or relocating to another point of safety during an emergency should not present obstacles to occupants trying to do so. One of the greatest impediments to this free egress is an unexpected and noncompliant locked door.  Fundamental door operation requirements ensure that doors are readily openable, easy to operate and available for use when the building is occupied. However, when security needs also dictate a need for additional protection, balancing that security need with additional life safety measures will help to ensure occupants continue to be offered safe and reliable means of egress during emergency situations.

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Kristin Bigda
Technical Lead and Principal Fire Protection Engineer with a focus on building and life safety related content.

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