Delayed Egress Locks: Controlled Exit Under the Code

What a Delayed Egress System Is

ANSI/BHMA A156.24 describes these products as hardware "used in connection with conventional exit devices or locks causing the doors to remain locked after releasing actuation for a predetermined length of time."

In practice a delayed egress system can be built in several ways. I Dig Hardware lists three common configurations:

• Panic hardware or fire exit hardware with a built-in delayed egress function
• Electromagnetic locks with integrated delayed egress electronics
• Other electrified locks paired with a separate delayed egress controller

Whatever the hardware, the behavior required by the codes is the same.

How the Delay Works

The sequence below follows the 2021 and 2024 International Building Code (IBC) text and Greene's comparison of the I-Codes and NFPA codes.

1. An attempt to exit starts the timer. Under current codes, the delay must begin when a force of no more than 15 pounds is applied to the egress-side hardware for no more than 3 seconds. The IBC calls this "an irreversible process." Greene notes that before the 2015 IBC, the trigger was a 1-second attempt.
2. An alarm sounds. Starting the process must activate an audible signal near the door. The codes do not dictate the type of sound.
3. The door releases. After no more than 15 seconds (or 30 seconds where approved), the door unlocks in the direction of egress, and the next push opens it.
4. Someone must reset it. Rearming must be done "by manual means only." Greene explains that this lets staff check why the lock was triggered before resetting it. She notes that before 2000 some codes allowed automatic relocking. Current codes do not.

When It Must Release Immediately

Delayed egress is only allowed because it gives way in an emergency. The 2021 IBC (Section 1010.2.13.1) requires the delay to deactivate, allowing immediate free egress:

• when the automatic sprinkler system or automatic fire detection system activates
• on loss of power to the lock or locking system
• from a switch at the fire command center and other approved locations

Greene notes that the NFPA codes are more specific about which detection events must release the lock. Both families of codes require emergency lighting on the egress side of the door.

Signs, Listings, and Limits

The IBC requires a sign on the door, located above and within 12 inches of the exit hardware. For a door that swings in the direction of egress it reads: "PUSH UNTIL ALARM SOUNDS. DOOR CAN BE OPENED IN 15 [30] SECONDS." A door that swings the other way says "PULL." NFPA 101 uses the same wording with its own placement and lettering rules.

Other high-level limits in the 2021 IBC:

• Building protection. The building must be equipped throughout with an automatic sprinkler system or an approved automatic smoke or heat detection system. Courtroom applications specifically require sprinklers.
• Occupancies. Delayed egress is permitted in listed occupancy groups (B, F, I, M, R, S, and U), plus limited educational and courtroom cases added in the 2018 editions. Greene notes that the 2018 I-Codes began allowing delayed egress on classroom doors serving fewer than 50 occupants.
• One per path. An egress path may pass through only one delayed egress door, with exceptions for certain institutional occupancies that allow two with a combined delay of no more than 30 seconds.
• Listing. The 2021 IBC requires delayed egress units to be listed to UL 294. The 2024 IBC text allows the locking device to be listed to UL 294 or UL 1034.

The section number moves between editions. Greene lists it as 1010.1.9.7 in 2015, 1010.1.9.8 in 2018, 1010.2.13 in 2021, and 1010.2.12 in 2024. For NFPA 101, she cites 7.2.1.6.1 (2021 and 2024 editions). Always check the edition your jurisdiction has adopted, along with any state or local amendments.

The BHMA Standard: A156.24

The product standard is ANSI/BHMA A156.24. BHMA's current Hardware Highlights summary covers the 2022 edition. It describes performance tests including:

• Durability: 10,000 cycles of a delayed egress operation (with a 15-second maximum delay and a zero-to-three-second pre-delay).
• Strength: a 400 lbf load applied near the latch edge while the system is actuated, held through the delay period, after which the device must work normally.
• Egress under load: a 250 lbf load during the delay. The test fails if the door opens before the delay ends or does not open when it ends.
• Electrical: operation at ±15% of rated voltage, and ESD immunity to IEC 61000-4-2, level 4.

BHMA's summary also repeats the code language. A force of no more than 15 lbf starts the irreversible process, and the release mechanism must need only one motion and be "obvious in all lighting conditions."

Delayed Egress vs. Related Hardware

Delayed egress is one of several special locking arrangements, and the categories are easy to confuse:

• Request-to-exit (REX): a sensor or switch that signals an access control system that someone is leaving. It does not delay anyone.
• Electric latch retraction: retracts an exit device's latch remotely, usually for access or dogging. There is no egress delay.
• Controlled egress locking (health care): a separate code provision for certain care units, with its own rules. It is not covered here.

Related Topics

• Panic hardware: exit devices that often carry the delay function
• Electromagnetic locks: maglocks with delayed egress electronics
• Request-to-exit devices: signaling, not delaying
• Electric latch retraction: remote latch control
• Access control: the systems these locks connect to
• Fire-rated door hardware: labeled openings
• Door handing: swing direction and the PUSH/PULL sign

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