If this article looks familiar, you’ve been reading iDigHardware for a long time. 🙂 I last wrote a Decoded article on this topic in 2014, but the requirements have changed, so here’s an update.
This post was published in Door Security + Safety
Code development for the US model codes is based on a consensus process, where code change proposals can be submitted by any individual or organization. In a series of hearings, the changes are discussed – often at length and on multiple occasions. A technical committee responsible for that particular code or section will then decide whether or not to include the change in the next edition of the code.
One of the challenges of this code development process is that the next cycle is beginning just as the previous edition is being published. For example, proposals for the 2024 model codes were due in the first half of 2021, when few if any states had adopted the 2021 editions. This means that if there is a problem with the new code, or a requirement that is unclear, it is unlikely to be noticed in time to address it in the following edition.
It’s important to be aware of these issues, because if you are reading the code without knowing the history of what has occurred, that may affect how you interpret the requirements. A perfect example of this is related to key-operated locks on the main entrance doors serving a building or tenant space. A change was made to the 2015 International Building Code (IBC), and years later we are still trying to modify the code to clarify the intent.
When most of us think about doors in a means of egress, we automatically assume that the doors must provide free egress at all times. There are very few exceptions to this rule, but both the IBC and NFPA 101 – Life Safety Code allow key-operated locks under certain circumstances. The idea is that a double-cylinder deadbolt installed on the main entrance door will have to be unlocked in order for the building to be occupied, and the door will allow egress. If employees are present in the building when main door is locked, they will have access to other exits.
Prior to the 2015 edition of the IBC, the code specified that locks that are key-operated on the egress side could be installed on a building’s main exterior door or doors, if the following criteria were met:
- The use group must be one of the following:
- Assembly occupancy with an occupant load of 300 people or less,
- Business, factory, mercantile, or storage occupancy, or
- A place of religious worship.
- The locking device must be readily distinguishable as locked – typically the lock will have an indicator which reads “open” or “locked.”
- Signage on the egress side of the door or adjacent to the door must state “THIS DOOR TO REMAIN UNLOCKED WHEN BUILDING IS OCCUPIED.” The letters on the sign must be at least 1 inch high on a contrasting background. This signage serves as a reminder to employees, but also advises the public that the door must be unlocked when they are present.
- A building official may revoke the use of a key-operated lock for due cause.
In the 2015 edition of the IBC, the word “exterior” was removed from this section, and a slight change was made to the text of the signage (the other criteria did not change). The signage must now state “THIS DOOR TO REMAIN UNLOCKED WHEN THIS SPACE IS OCCUPIED.” The intent of this change was to allow the use of double-cylinder locks meeting the criteria specified in the code, on the main entrance to a tenant space such as a retail store in a mall. Because these doors are often interior doors leading from the mall to the store, the code change proposal removed the word exterior in order to make it applicable to interior doors as well.
The impact of this change was not discovered until the 2015 code was adopted and interpretations of the revised section began to be made. With the code referencing the main door or doors to a space, some architects, end users, and others began to specify or install double-cylinder deadbolts on doors that were not the main entrance to the building or the main entrance to a tenant space. Without clarifying language in the code, it could be interpreted to mean that the key-operated lock could be used on the main entrance door to any room within a building. Clearly, that would not meet the intent of the code which is to facilitate safe egress. A proposal has been made for the 2024 IBC, in hopes of clarifying the intent of this section.
NFPA 101 – Life Safety Code includes slightly different requirements for key-operated locks, which more accurately reflect the intent of the model codes:
- Key-operated locks on the egress side of a door are limited to exterior door assemblies and interior door assemblies to an individual tenant space or to a single tenant space, where allowed by the occupancy chapters (consult the applicable occupancy chapter to see whether a key-operated lock is acceptable).
- When a key-operated lock is installed, a readily visible, durable sign must be located on or adjacent to the door, reading: THIS DOOR TO REMAIN UNLOCKED WHEN THE BUILDING IS OCCUPIED or THIS DOOR TO REMAIN UNLOCKED WHEN THE SPACE IS OCCUPIED. The letters on the sign must be at least 1 inch high on a contrasting background.
- The lock must be readily distinguishable as locked – typically with an indicator that reads “open” or “locked.”
- A key must be readily available to all occupants inside the building when it is locked.
- An Authority Having Jurisdiction (AHJ) may revoke these provisions for cause.
- As stated in Annex A of NFPA 101, if the entrance consists of a vestibule, the key-operated lock may be installed on either the exterior or interior door of the vestibule.
As always, local code requirements may vary from the model codes referenced here, and the AHJ has the final say. Note that a section has been added to the 2021 IBC that allows key-operated locks on egress doors serving exterior spaces such as courtyards and roof terraces, if certain criteria are met. Refer to the 2020 article called Decoded: Egress From Exterior Spaces for more information on this application.