“When am I required to have my elevator serve as an accessible means of egress?”
A question frequently asked and for the purposes of this response, the assumption is that the project is located in Massachusetts and will be designed under 780 CMR, Massachusetts State Building Code (9th Edition), which is based on the 2015 International Building Code (IBC).780 CMR 1009.2.1 requires at least one accessible means of egress to be an elevator in buildings where a required accessible floor is four or more stories above or below a level of exit discharge. The code defines the level of exit discharge as the story at which an exit terminates and an exit discharge begins. On a flat site, a building that is “four stories above the level of exit discharge” would equate to a 5-story building. See the figure below for examples. Once this number of stories is reached, at least one elevator serving all floors in the building would be required to serve as an accessible means of egress. In order to be considered as an accessible means of egress, the elevator would be required to comply with the provisions of 780 CMR 1009.4, including being equipped with a standby power source. To meet the standby power requirement, it is our experience that this necessitates an emergency generator and not battery-backup to satisfy.
When discussing such buildings, another common question is, “Are there any options to avoid installing an emergency generator to serve as the standby power source when an elevator is required as an accessible means of egress?”
Foremost, if the building is classified as a high-rise, elevators are required to be equipped with a standby power source in accordance with 780 CMR 403.4.8.3, and the generator is not able to be avoided.
If the building is not a high-rise, there may be an option to avoid an emergency generator depending on the specific building design. If the building is a low-rise and is more than four stories above the level of exit discharge, an alternate option is to utilize horizontal exits. 780 CMR 1009.2.1, Exception 1 states that in buildings sprinklered in accordance with NFPA 13 or 13R, an elevator is not required to serve as an accessible means of egress on floors provided with a horizontal exit located at or above the levels of exit discharge. This effectively means the following:
- The building cannot have any accessible stories located below the level of exit discharge;
- Horizontal exits, complying with 780 CMR 1026, must be provided on all floors.
Horizontal exits have their own series of requirements that must be met. A few considerations before you get rid of the generator include, but are not limited to:
- In most occupancies, horizontal exits are not permitted to serve as more than one-half of the required number of exit or egress capacity (780 CMR 1026.1).
- The horizontal exit must be 2-hour rated with 90-minute opening protectives and be continuous from exterior wall to exterior wall. Any cross-corridor doors will likely need to be bi-directional assuming that they serve more than 49 occupants on either side (780 CMR 1026.3).
- The horizontal exit must extend vertically through all levels of the building. It does not necessarily need to align vertically, but where horizontal transitions occur between stories, the floor/ceiling assembly and all supporting construction must be 2-hour rated (780 CMR 1026.2).
- An adequate refuge area complying with 780 CMR 1026.4 must be provided on both sides of the horizontal exit (780 CMR 1026.4). The refuge area must be adequate to accommodate the original occupant load of the refuge area plus the occupant load anticipated from the adjoining compartment.
- Standpipe hose connections may be required adjacent to the horizontal exit in accordance with 780 CMR 905.4(2).
- Exit signage and manual pull stations are required for the horizontal exit doors serving as a means of egress.
To summarize, there may be an option to avoid installing an emergency generator when elevators are required to serve as an accessible means of egress. However, there are a number of factors that must be considered including whether the building is a high-rise and whether there are any accessible stories located below the level of exit discharge. Beyond this, horizontal exits come with their own slew of requirements which could have significant implications on the design and cost of your project. Contact us today to see how we can help make the best informed decision on your project.