Welcome back to the 10th Edition Major Changes blog series. This post is Part 2 on Means of Egress, focusing on changes associated with delayed egress locking, classroom locking, and door sizing requirements.
Delayed Egress Locking
Delayed egress locking systems are intended to be used where security is a concern, but egress needs to be maintained. The 2015 edition of the International Building Code (IBC) permits delayed egress locking in doors serving occupancies other than Group A, E, or H in buildings equipped throughout with an automatic sprinkler system or an approved automatic smoke or heat detection system.
The 10th edition of 780 CMR will expand use of delayed egress locking to secondary exits of courtrooms (Group A-3). Given the complex circulation and egress arrangements in courthouses, delayed egress locking is preferred to prevent unauthorized occupants from accessing secure spaces in the building from the courtroom where the public, inmates, and courthouse employees can be located simultaneously.
Group E classrooms with less than 50 occupants will now also be permitted to be provided with delayed egress locking. This change is driven by the need to prevent wandering children while maintaining a fully functioning means of egress.
There continues to be heightened sensitivity in trying to balance the security of a school classroom with classroom egress. With traditional classroom lock sets, teachers are required to leave the room to lock the door for a defend-in-place strategy which puts teachers at risk. However, modified locking devices that have been developed and used over the years do not allow for free egress. The new code will allow Group E and Group B educational occupancies to be provided with special locking arrangements under the following conditions:
- The door can be unlocked from outside the room with a key or from a remote location.
- The door can be opened from inside the room when locked.
- Modifications to listed panic hardware, fire door hardware, or door closers are not permitted.
This code change aims to create a balance between security and egress.
Currently, the width of a swinging door leaf is not permitted to exceed 48 inches nominal. The next code will remove this maximum door width requirement and instead defer to the door opening force requirements that already exist. Essentially, the size of the door will be inherently limited by door opening force, creating more of a performance-based requirement that may provide more flexibility to designers.
Thanks for tuning in to this week’s 10th Edition blog post. It’s important to highlight that the 10th edition of 780 CMR has not been finalized or adopted in Massachusetts and is potentially subject to further changes. Our current projection for the adoption of the 10th edition is Q2 of 2024 – see our prior post which outlines the overall process and timeline.
Stay connected for more Insights posts as we continue our “10th Edition Major Changes” series as part of CRC’s 10th Anniversary!