In almost every building, owners or tenants have a need for some level of security or access control. The IBC covers a wide range of door locking and control techniques, but the shear number of sections and underlying requirements can be tough to digest. Many folks have trouble knowing which code sections apply, and even if the correct section is identified, it can be a challenge to understand the requirements.

In this post, I take a number of these door locking requirements and translate them into (hopefully) more clear and concise language. I also provide some general commentary on my experience in using each type of door/locking arrangement. References are provided to the last 3 editions of the IBC.

Click one of the door/lock types in table below to jump to that section.

Many designers don't realize that a revolving door can be used in an egress path, as long as certain requirements are met.

All revolving doors must meet the following requirements, but be sure to check out the paragraph below this one for additional requirements for egress/non-egress doors.

1. Comply with BHMA A156.27 and the manufacturer's instructions.
2. Each revolving door must have "breakout" capability per BHMA A156.27 and have an aggregate width of at least 36 inches.
3. A revolving door must be at least 10 feet from the top or bottom of stairs and escalators. A dispersal area must be provided between the stair/escalator and the revolving doors.
4. The revolving door speed (in RPMs) cannot exceed the maximum rpm as specified in BHMA A156.27. Manual revolving doors must comply with Table 1010.1.4.1(1). Automatic or power-operated revolving doors shall comply with Table 1010.1.4.1(2).
5. An emergency stop switch is required near each entry point of power or automatic operated revolving doors within 48 inches of the door and between 24 inches and 48 inches above the floor. The activation area of the emergency stop switch button must be at least 1 inch in diameter and red in color.
6. Each revolving door must have a side-hinged swinging door that complies with IBC 1010.1 in the same wall and within 10 feet of the revolving door.
7. Revolving doors cannot be part of a required accessible route.

Revolving Doors in Egress Components must meet the following requirements:

1. Count towards no more than 50% or required egress width or capacity.
2. Each door counts towards a maximum of 50 occupants when performing egress calculations.
3. Maximum breakout force of 130 pounds.

Revolving doors that are not egress components must have a breakout force of 180 pounds or less. A breakout force of more than 180 pounds is permitted if the breakout force reduces to 130 pounds or less under one of the following conditions:

1. Door power failure
2. Sprinkler system activation
3. Smoke detector activation with 75 feet of the revolving doors
4. Activation of a manual control switch in a clearly identified location

Power operated doors are common in building entrances, as well as in occupancies where people may struggle to open a door by themselves, such as a Group I-2 nursing home.

Any egress door that is operated or assisted by power must have the capability to be manually opened or closed. The forces required to open the doors must comply with IBC 1010.1.3 door opening force requirements, except the force to set the door in motion must not exceed 50 pounds. The door must have the capability to open from any position to the full width of the opening when a force is applied on the egress side.

Power-operated swinging doors, power-operated sliding doors and power-operated folding doors must comply with BHMA A156.10. Power-assisted swinging doors and low-energy power-operated swinging doors must comply with BHMA A156.19. (2018 and Beyond): Low-energy power-operated sliding doors and low-energy power-operated folding doors must comply with BHMA A156.38.

Exceptions to the above requirements:

1. Group I-2 occupancies
2. Special purpose horizontal sliding, accordion or folding doors (see related section in this article)
3. For a biparting door in the emergency breakout mode, a door leaf located within a multiple-leaf opening is exempt from the minimum 32-inch single-leaf requirement, provided that a minimum 32-inch clear opening is provided when the two biparting leaves meeting in the center are broken out.

Special purpose doors, such as horizontal sliding doors, are most commonly used in situations where a fire door is needed in an egress path but there is a desire to have the door normally open, or perhaps concealed. A sliding or folding fire shutter would fall into this category. These are the only type of doors in this article that specifically require an integrated standby power supply, typically provided as a battery pack above the door.

Horizontal sliding, accordion or folding doors can be used in all occupancies except Group H when allowed by Exception 6 of IBC 1010.1.2. Use of these doors requires the following:

1. The doors are power operated and are capable of being operated manually in the event of power failure.
2. The doors are openable by a simple method from both sides without special knowledge or effort.
3. The force required to operate the door cannot exceed 30 pounds to set the door in motion and 15 pounds to close the door or open it to the minimum required width.
4. The door must be openable with a maximum force of 15 pounds when a force of 250 pounds  is applied perpendicular to the door adjacent to the operating device.
5. The door assembly must comply with the applicable fire protection rating and, where rated, must be:
   1. Self-closing or automatic closing by smoke detection in accordance with IBC 716.2.6.6.
   2. Installed in accordance with NFPA 80.
   3. Comply with IBC 716.
6. The door assembly must have an integrated standby power supply.
7. The door assembly power supply must be electrically supervised.
8. The door must open to the minimum required width within 10 seconds of the operating device.

Locking of egress doors in educational occupancies has been a hotly-debated topic in recent code cycles. Some argue that being able to lock a classroom door from the inside is necessary to protect occupants during certain emergency situations. Others argue that this actually poses a greater risk to occupants inside the classroom. The requirements for such locking arrangements are provided below.

In Group E occupancies, Group B educational occupancies and (2021 only) Group I-4 occupancies, egress doors from classrooms, offices and other occupied rooms with locking arrangements designed to keep intruders from entering the room are permitted with the following requirements:

1. The door is capable of being unlocked from outside the room with a key or other approved method. Remote door unlocking is permitted in addition to the key.
2. The door is openable from within the room per IBC 1010.2
3. Modification are not permitted to listed panic hardware, fire door hardware or closers.
4. (2021 only) Modifications to fire doors assemblies must be in accordance with NFPA 80.

Secutiry grilles are an important part of building security systems, particularly in retail spaces such as a shopping mall. The IBC allows security grilles in Group M occupancies, as well as Groups B, F and S.

In Groups B, F, M and S, horizontal sliding or vertical security grilles are permitted at the main exit and must be openable from the inside without the use of a key, special knowledge or effort when the space is occupied. The grilles must remain secured in the full-open position anytime the space is occupied by the general public. Where two or more means of egress are required, no more than half of the exits or exit access doorways can be equipped with security grilles.

Group I-1 and I-2 occupancies include assisted living facilities, nursing homes, hospitals, psychiatric treatment centers, all facilities where people receiving care may​ require some level of containment. There are many situations where allowing a care recipient to freely exit may actually endanger that person or others. The IBC recognizes this risk and provides an avenue to provide locking control on egress doors in such occupancies.

Electric locking systems are permitted in Group I-1 and I-2 occupancies where the clinical needs of the care recipient require their containment. In order to use this code provision, the building must be either fully sprinkler-protected or equipped throughout with smoke detectors and meet all of the following requirements:

1. The door must unlock upon actuation of the sprinkler or smoke detection system.
2. The door must unlock upon power loss.
3. The door must have an unlocking switch, located at the fire command center, nursing station or other approved location, that directly breaks power to the lock.
4. No more than one controlled egress door before reaching an exit
5. Door unlocking procures must be included and approved in the required Fire Code emergency planning (see IFC Chapter 4).
6. All clinical staff must have a key or other means to operate the locked door
7. Emergency lighting is required at the door.
8. The door locking system must be UL 294 listed.

Exceptions: Items 1-4 above do not apply to the following situations:

1. Areas where persons require restraint or containment as part of the function of a psychiatric treatment area or (2021 only) cognitive treatment area.
2. Where a listed egress control system is used to reduce child abduction risk from nursery and obstetric area of a Group I-2 hospital.

Using a delayed egress system is one of the most common approaches to achieve some level of access control on an egress door. They provide a deterrent to occupants using the door unless there is a true need (e.g. a fire emergency), but still allow for full egress use after the delay period. A key limitation of delayed egress systems is they are limited by occupancy , for example, Group A spaces cannot use delayed egress systems, regardless of the occupant load.

Where permitted:

2015:
Delayed egress locking systems are permitted in any occupancy except Groups A, E or H when the building is fully sprinkler protected per NFPA 13 or provided with smoke/heat detection throughout.

2018 and Beyond:
Delayed egress locking systems are permitted in the following situations when the building is fully sprinkler protected per NFPA 13 or provided with smoke/heat detection throughout.

1. Group B, F, I, M, R, S and U
2. Group E classrooms with an occupant load less than 50
3. In courtrooms, on other than the main exit doors, when the building is fully sprinkler protected per NFPA 13.

The delayed egress locking system must meet all of the following requirements:

1. The delay electronics must allow immediate and free egress upon actuation of the sprinkler system or fire detection system.
2. The delay electronics must allow immediate and free egress upon power loss.
3. The delay electronics must have the capability to be deactivated from the fire command center or other approved location.
4. When an effort is applied to the egress door hardware for not more than 3 seconds, an irreversible process must star that allows for the egress door to open in 15 seconds or less. The irreversible process must activate an audible signal near the door. Once the delayed egress door has been deactivated, the door can only be rearmed by manual means.
   1. Exception: Where approved by the AHJ, a delay of not more than 30 seconds is permitted.
5. The egress path cannot pass through more than one delayed egress locking system.
   1. 2015 Exception: In Groups I-2 or I-3, the egress path can pass through up to two delayed egress locking systems if the combined delay is 30 seconds or less.
   2. 2018 Exception: In Groups I-2 or I-3, the egress path can pass through up to two delayed egress locking systems if the combined delay is 30 seconds or less. In Groups I-1 or I-4, the egress path can pass through up to two delayed egress locking systems if the combined delay is 30 seconds or less and the building is fully sprinkler protected per NFPA 13.
   3. 2021 Exception: In Groups I-1 Condition 2, I-2 or I-3, the egress path can pass through up to two delayed egress locking systems if the combined delay is 30 seconds or less. In Groups I-1 Condition 1 or I-4, the egress path can pass through up to two delayed egress locking systems if the combined delay is 30 seconds or less and the building is fully sprinkler protected per NFPA 13.
6. A sign must be provided on the door and located above and within 12 inches of the door exit hardware:
   1. For doors swinging in direction of egress, the sign must read “PUSH UNTIL ALARM SOUNDS. DOOR CAN BE OPENED IN 15 [30] SECONDS.”
   2. For doors swinging in against the direction of egress, the sign must read “PULL UNTIL ALARM SOUNDS. DOOR CAN BE OPENED IN 15 [30] SECONDS.”
   3. The sign must comply with the visual character requirements in ICC A117.1.
   4. Exception: Where approved in Group I occupancies, the sign is not required where care recipients have a clinical needs requiring restraint or containment as part of the function of the treatment area.
7. Emergency lighting must be provided on the egress side of the door.
8. The delayed egress systems must be UL 294 listed.

Electrically locked doors using a sensor release are frequently used in situations where it is helpful to have an egress door unlock prior to an occupant physically reaching the door. Note that this type of door release functionality can be used in conjunction with an electromagnetic locking mechanism (Mag Lock).

Where Permitted:

2015:
Sensor release locks are permitted on any egress door in Groups A, B, E, I-1, I-2, I-4, M, R-1 or R-2 occupancy.

​2018 and Beyond:
Sensor release locks are permitted on any egress door except in Group H occupancies.

Sensor release locks must be installed and operated per the following requirements:

1. Sensor installed on egress side of door to detect an occupant approaching the door and cause the electric lock system to unlock.
2. Door unlocks upon loss of power or signal to the sensor.
3. Door unlocks upon loss of power to the lock or locking system.
4. Doors can be unlocked from a manual device located 40” to 48” above the floor and with 5 feet of the doors. The unlocking device must be readily accessible and be clearly identified with a “PUSH TO EXIT” sign. The unlocking device must directly interrupt power to the lock independent of other electronics and keep the door unlocked for at least 30 seconds.
5. Door unlocks upon activation of the building fire alarm system and remain unlocked until fire alarm system is reset.
6. Door unlocks upon activation of the sprinkler system or fire detection system and remain unlocked until the fire alarm is reset.
7. Door lock system must be UL 294 listed.
8. (2021 Only) Emergency lighting must be provided on the egress side of the door.

Electromagnetically locked egress doors, commonly referred to as “Mag Locks” are permitted in Group A, B, E, I-1, I-2, M, R-1 and R-2 occupancies. Use of such locks requires a built-in switch on the door and compliance with the following:

1. Hardware is affixed directly to the door leaf and has an obvious method of operation under all lighting conditions.
2. Hardware can be operated with one hand.
3. Operating the door hardware immediately interrupts power to the Mag Lock and unlocks the door immediately.
4. Door unlocks upon lows of power to the locking system.
5. Where panic or fire exit hardware is required, operation of that hardware also releases the Mag Lock.
6. Lock system must be UL 294 listed.

Starting in 2018, the Mag Lock section above was expanded to any electric locking system with a door hardware release. The requirements here are essentially the same as the Mag lock requirements from 2015.

Door hardware release of electric locking systems on egress doors is permitted in all occupancies except Group H and requires compliances with the following:

1. Hardware is affixed directly to the door leaf and has an obvious method of operation under all lighting conditions.
2. Hardware can be operated with one hand and meets IBC unlatching requirements.
3. Operating the door hardware immediately interrupts power to the lock and unlocks the door immediately.
4. Door unlocks upon lows of power to the locking system.
5. Where panic or fire exit hardware is required, operation of that hardware also releases the lock.
6. Lock system must be UL 294 listed.

Correctional and detention facilities are permitted to have locked egress doors when occupants are required to have controlled movements for security purposes. Such doors must have an egress control devices that unlocks the door manually and by at least one of the following means:

1. Activation of the building sprinkler system
2. Actvaition of a manual fire alarm pull station
3. A signal from a constantly attended location.

In the 2015 IBC, use of this provision is limited to Groups A-2, A-3, A-4, B, E, F, I-2, I-3, M and S occupancies within correctional and detention facilities. In 2018 and beyond, use of this section is permitted in any building within a correctional and detention facility.

Generally, interior stair doors must be openable from both sides without the use of a key or special knowledge, though the following exceptions allow you to lock the stair door:

1. Stair discharge doors can be locked from the outside (must be unlocked in direction leaving the stair).
2. Stair doors in high rise buildings complying with IBC 403.5.3 (see section below).
3. (2015 Only): In stairs serving 4 stories or fewer, stair doors can be locked from the inside provide they have the capability of being simultaneously unlocked (without unlatching) by a signal from the fire command center or location inside the main entrance of the building.
4. (2018 and Beyond): Stair doors can be locked from the inside provide they have the capability of being simultaneously unlocked (without unlatching) by a signal from the fire command center or location inside the main entrance of the building.
5. Stair doors in Group B, F, M and S occupancies where the only interior access to a tenant space is from the exit stair can be locked from the inside of the stair (must be unlocked in direction of egress).
6. Stair doors in Group R-2 dwelling units where the only interior access to the unit is from the exit stair can be locked from the inside of the stair (must be unlocked in direction of egress).

In high rise buildings, stairway doors can be unlocked from the stairway side provided they have the capability of being unlocked (without unlatching) by a signal from the fire command center. when this provision is used, a telephone or other two-way communication system connected to a constantly attended location is required on every fifth floor in every stairway with locked doors.

Panice and fire exit hardware itself does not involve locking a door. Rather, panic or fire exit hardware can be used in conjunction with one of the locking arrangement described in this article. 

In the A/E design community, the term "open stair" is frequently used to describe a stair that is not enclosed with walls, partitions or barriers. While "open stair" is not a term used in the International Building Code, it generally aligns with a stairway (which is a defined term in the IBC) not used for egress purposes or an exit access stairway (also a defined term). The terms "communicating stair" and "convenience stair" are also used in the same line of discussion, though depending on the situation, these could be referring to communicating spaces or convenience openings, both types of vertical openings defined in NFPA 101.

In this post, we'll review the IBC requirements for open stairs and describe several code paths that can be used to provide open stairs in your design. I will use the term "open stair" throughout the post, but remember, since this is not a defined term, any formal documentation on drawings, plans etc. should use the proper nomenclature identified in this overview. This post will be limited to stairs within a building and will not address exterior stairways.

Stairway Connecting Levels within a Story
The first and most simple type of open stair connects one or more levels within a single story. This stair could be provided to access a raised floor area or a mezzanine, or to access areas on a story that are at different elevations due to a sloping site.

​If the open stair is not used as part of the means of egress, the IBC would view it as simply a "stairway." If it is on the path of egress, it then becomes an exit access stairway. In either case, since this type of stair does not connect multiple stories, there is no code requirement to enclose the stairway or provide a rated separation (IBC 1019.2).

One other important point for this type of open stair is the requirement for accessible means of egress (IBC 1009). An exit access stair connecting levels on the same story is not permitted to be part of an accessible means of egress, unless the stair is providing the means of egress from a mezzanine (IBC 1009.3.1). If you are not sure how to address required vs. accessible means of egress requirements, check out this post for more details.

Stairway Connecting Two Stories
If your open stair does connect two stories, a few additional requirements are triggered. First, IBC 712.1.9 gives a number of requirements for vertical two-story openings. These include:

• Does not penetrate a horizontal assembly separating a fire area or smoke compartment
• Is not concealed within a wall, floor or ceiling assembly
• Is not open to a Group I or R corridor
• Is not open to any corridor on a nonsprinklered floor
• Is separated from openings serving other floors by construction conforming to required shafts

​If your open stair is part of the means of egress (exit access stairway), IBC 1019.3 gives similar requirements. Note that open stairs connecting two stories are not permitted in Group I-2 and I-3 occupancies.

Stairway Connecting Three or More Stories
If your open stair connects three or more stories, the most common approach is to use a draft curtain and closely spaced sprinklers per IBC 1019.3.4. Use of this provision requires the following:

• The building must be fully sprinkler-protected in accordance with NFPA 13
• The area of the vertical opening must not exceed twice the horizontal projected area of the stairway
• The opening must be protected with a draft curtain and sprinklers per NFPA 13

​In Group B and M occupancies, there is no limit to the number of stories that can be connected with this approach. In all other occupancies, this is limited to four connected stories, except Groups I-2 and I-3, where it is not permitted at all.

Open Stairs in Group R Occupancies
In Group R-1, R-2 and R-3 occupancies, open stairs up to four stories are permitted if they are contained within a single dwelling unit, sleeping unit or live/work unit.

Open stairs are also permitted in Group R-3 congregate living facilities and Group R-4 occupancies.

​Open Stairs within an Atrium
If located within an atrium, open stairs are permitted with no limit to the number of stories connected. Keep in mind that atriums have a host of additional requirements in the code, such as smoke control and rated separation from other building spaces.  Open stairs in an atrium are permitted to serve as exit access stairways, though the travel distance when using such stairs is limited to 200 feet (IBC 404.9.3).

​Other Situations
There are a few other situations where the code allows open stairs without any rated enclosure or separation:

• In open parking garages where the stair serves only the parking garage
• In smoke-protected or open-air assembly seating areas complying with IBC 1029.7
• In theaters, auditoriums and sports facilities, open stairs connecting balconies, galleries or press boxes to the main assembly floor
• Stairs within mall buildings complying with IBC 402

There are many cases where the IBC allows open stairs. When open stairs are used as part of the means of egress for a building, they are considered "exit access stairways." Otherwise, they would fall under the "stairway" definition in the code. If your project is required to comply with NFPA 101, be sure to check out Chapter 8, which has more stringent requirements for vertical openings than the IBC.

It's been a full summer here on my end, at least in one sense. While the pandemic has forced vacation cancellations and generally fewer social gatherings, work has been full steam ahead for the past few months. I've also been working on a weekly basis to help PE Roadmap clients as they study for the Fire Protection PE exam this fall. As we get towards the last remaining months before the October exam, I am looking forward to some more regular posts on the blog, which I anticipate to be a mixture of life safety tools, cheat sheets and code questions.

On another front, I've also had some recent conversations with Joe Meyer over at MeyerFire regarding our Code Calls initiative. While we are still soliciting feedback from Indiana AHJs regarding their local requirements, we are also looking for some ways to further jump start our progress. One of these is putting together a database that provides a link to State/City/County/Municipality local amendments, as well as the link to that jurisdiction's website where you can find contact information. Similar to the main Code Calls database, we are starting in Indiana and hoping to branch out from there. More on that in the coming months.

On a recent project, an architect I am working with received a comment stating that openings in stairways are only permitted from normally occupied spaces. I have come across this requirement before, which originates from IBC 1023.4.

While I am quite familiar with this requirement, the fact that it was brought up in this particular situation was shocking. That's because the floor in question, a basement, was designed with two exit stairs and an enclosed corridor running the length of the building and connecting the stairs. I've sketched up a simplified version of the layout below. The plan review comments indicated that the openings into the stairs were from not-normally occupied spaces and did not comply with IBC 1023.4.

If either of the stairs opened up directly into the mechanical, electrical or storage rooms, this comment would make sense to me. However, the openings into both stairs are from the corridor, which I have always considered normally occupied space. In fact, the IBC actually requires rated corridors to continue to an exit (IBC 1020.6). While the corridors in this design are not currently rated, if the code requires corridors continuity to an exit in certain situations, how could a corridor be considered not-normally occupied here?

Upon a followup conversation with the plan reviewer, the local jurisdiction has taken the position that because all of the rooms (mechanical, electrical and storage) on the floor are considered not-normally occupied, the corridor serving those rooms should be treated the same. The reviewer also cited concern that corridor could be used for storage and result in potential fire spread into the stair.

When I brought up potential solutions, it seems that rating the corridor (or providing a rated stair vestibule) would satisfy the jurisdictions concerns.

I would love to hear your thoughts on this situation. Should this corridor be considered not normally occupied? Does this design meet the intent of IBC 1023.4? Let me know in the comments section!

I'm currently working on a large, multi-family apartment building that includes several-hundred dwelling units. The building is four stories tall and each story has multiple exits. The building is divided up by several fire walls for allowable area purposes, so the exits are a combination of exit stairs and horizontal exits.

​In a recent discussion, the AHJ indicated that he thought Emergency Escape and Rescue Openings complying with IBC 1030 were required for each bedroom in the building. On past projects, I have not seen this required in buildings where each story has two or more exits, so I decided to do a deep dive into the code requirements.

This project is under the 2015 IBC, but I have also included the 2018 language below, as this seems to further clarify the requirements.

In the 2015 language, the first sentence seems to indicate that for a Group R-2 occupancies, the emergency escape requirements apply when triggered by Table 1006.3.2(1) or 1006.3.2(2). As I described in a recent cheat sheet for single exits, these tables are allowances for having a single exit or access to a single exit from a story. In this case, every story has multiple exits, so the provisions of these tables do not apply. The 2018 IBC makes this even clearer.

The AHJ on this project is pointing to the second sentence from the 2015 IBC 1030.1, stating that all sleeping rooms below the fourth story require the openings. The second paragraph from the 2018 IBC has similar language.

In my opinion, the first sentence of IBC 1030.1 essentially functions as scoping language for the rest of the requirements. Since this project does not meet the conditions described in this scoping sentence, the rest of the requirements do not apply and the openings are not required.

In a Group R-2 building where each story has multiple exits, are emergency escape and rescue openings required?

Let me know your thoughts in the comment box!

One other item to keep in mind - if your project is a single-family home, you may actually be permitted under the International Residential Code (IRC), not the IBC. The IRC also has requirements for emergency escape and resuce openings, so be sure to check those out if applicable to your project.

On a related note, I was recently asked to provide input for an article on Redfin for basement remodelling projects (likely permitted under the IRC). Check out the link to the article here!

​For years, architect clients have asked me for solutions to mitigate a dead end corridor condition. As a quick reference, dead ends are limited to 20 feet, except in Groups B, E, F, I-1, M, R-1, R-2, R-4, S and U with a full NFPA 13 sprinkler system, where the limit is increased to 50 feet (2015 IBC 1020.4).

But on a recent project, a local AHJ has taken the stance that a cross corridor door does not mitigate a dead end condition. I scheduled a meeting with the AHJ to explain how this has been done on other projects and to share the ICC interpretation, but they were reluctant to budge. After some negotiations, the AHJ allowed the door, but insisted that it not be held open and also required a large "Not an Exit" sign on the door itself.

I have drawn up a similar situation in the image below. The corridor is serving a Group A occupancy, so the dead end limit is 20 feet. The added door is shown in red.

Do cross-corridor doors mitigate the 20 foot dead end limit? Do you think they should be permitted to be held open?
Let me know your thoughts in the comment box!

Yet in certain locations, the crowds of people are growing.

For example, cities across the US are seeing a rise in temporary emergency shelters. Many hospitals are expanding with new temporary patient sleeping areas, and homeless shelters are expanding to arenas, convention centers and other large facilities to accommodate a drastic increase in occupants. In Alaska, one homeless shelter has taken over a sports arena and is housing double the number of people originally expected. In Arizona, one homeless shelter has moved to a head-to-toe sleeping mat arrangement to allow for some level of social distancing while still accommodating as many people as possible. You can find similar stories across the country. 

So what does this mean for calculating occupant loads? 

In the long term, it's impossible to say for sure. Things could very well go back to normal once the pandemic ends, leaving the nature of occupant loading strategies unaffected. But on the other hand, does COVID-19 change how we work and gather as a society? Will there be a sharp increase in the number of employees working from home when this is all over? Or separately, does the pandemic go on for quite some time such that we have to asses things differently as new buildings are designed in the coming months or years?

With the current CDC guidelines, the recommendation for social distancing involves maintaining 6 feet of separation from other individuals. Six feet of separation in both direction results in each occupant of a building taking up 36 square feet of space. 

So how might this impact an occupant load calculation?

Here's one example: a 750 square foot conference room with tables and chairs would normally be assigned an occupant load of 50 (using a factor of 15 square feet per occupant), but following the CDC guidelines, no more than 20 occupants should be in the room.

Another example is a 500 square foot classroom, which would normally be assigned an occupant load of 25 (using a factor of 20 square feet per occupant). But following the CDC guidelines, no more than 13 occupants should be in the room.

As long as the CDC guidance and government direction is in place, any gatherings or meetings that are still occurring will likely be smaller and less dense than normal. And with most schools around the US canceled and many meetings moving to a virtual format, there's a good change that many conference rooms and classrooms are vacated completely.

But what about locations where the crowds are increasing?

Let's take the temporary emergency shelter as an example.

As more and more people are impacted by COVID-19 and the demand for emergency shelters increases, staff members of these locations are already facing the growing tension of trying to accommodate more people while still maintaining some level of social distancing.

During Hurricane Katrina in 2005, the field of the Superdome in New Orleans was converted to an emergency shelter for displaced local residents. As you can see from the image below, the field was densely packed with sleeping cots. For families, cots were pushed together with no space in between and each group of cots was only 1-2 feet away from the next group.

​Now compare this to a recent photo from a temporary emergency shelter in Alaska, where there is at least 6 feet of space between each sleeping cot.

Assuming the pandemic continues and the number of people forced into shelters grows, the challenge of this tension will also grow. With a limited amount of space and resources, is it better to limit the occupant load in order to maintain social distancing? Or should shelters attempt to help more people at the expense of housing people closer together?

The world is facing an unprecedented situation in the current COVID-19 pandemic. In the short term, major cities are seeing a complete desertion of many offices, public spaces and streets. Yet emergency facilities such as hospitals and shelters are seeing a sharp increase in occupants.

For life safety consultants like me, this raises the question: how does this impact occupant load strategies?

While I'm hopeful that the pandemic ends soon and life returns to normal, I also have a small inkling that COVID-19 will have some change on how we work and gather as a society in the future. Maybe it will be an increase in the number of people working from home. Perhaps large public gatherings look different in the future. At this point, it's impossible to say for sure.

What are your thoughts? Have you seen occupant loads change drastically in your community? Do you expect the pandemic to change how we gather together in the future? Please share your thoughts in the comments section!

​

All definitions and requirements are from the 2015 International Building Code (IBC). Note that the IBC does not always include the word “required” when referring to a means of egress. Generally, when the code references either “required means of egress” or “means of egress,” it’s referring to the first definition below. The IBC always uses the full term “accessible means of egress” when referring to the second definition.

Definitions (IBC 202):
Means of Egress: “A continuous and unobstructed path of vertical and horizontal egress travel from any occupied portion of a building or structure to a public way. A means of egress consists of three separate and distinct parts: the exit access, the exit and the exit discharge.”

Accessible Means of Egress: “A continuous and unobstructed way of egress travel from any accessible point in a building or facility to a public way.”

From these definitions, notice that both involve “a continuous and unobstructed…” path or way of egress, and that both will lead you “…to a public way.” But the definitions differ in starting point. For a means of egress, the starting point is “from any occupied portion of a building or structure,” whereas for an accessible means of egress, the starting point is “an accessible point in a building or facility.”

So simply from these definitions, we can gather an important distinction: an accessible means of egress only originates from an accessible point in a building or facility. If a building or portion of a building is not required to be accessible, it is not required to have an accessible means of egress (IBC 1009.1).

Means of Egress Components
A required means of egress consists of 3 distinct components: the exit access, the exit and the exit discharge.

*serving levels other than the level of exit discharge
**serving exits at the level of exit discharge

You’ll notice that some of these components can also be part of a required means of egress – interior and exterior exit stairways, exit access stairways and ramps. But an accessible means of egress can include specific components for occupants who need accessible accommodations, such as elevators, lifts and exterior areas for rescue assistance, that are not part of the required means of egress.

Another important component is the accessible route, which is always required as part of an accessible means of egress. Since all portions of a building that are accessible require both an accessible route an accessible means of egress, you can’t provide one without the other. An accessible route could also be part of the required means of egress, but it’s not necessarily required.

Key Differences
Unlike the required means of egress, elevators can be used as a part of an accessible means of egress. And for buildings with an accessible floor located four or more stories above the level of exit discharge, at least one elevator is required as part of the accessible means of egress (IBC 1009.2.1).

Another important distinction exists for exit access stairs, which are permitted as part of the required means of egress and in certain cases as part of an accessible means of egress. However, exit access stairs that connect levels in the same story are not permitted as part of an accessible means of egress (IBC 1009.3). This means that stairs connecting levels within a single story, even if a just single step, are not considered part of an accessible means of egress.

Accessible Means of Egress: Where Required
The criteria for where an accessible means of egress is required are simple. Any accessible space within a building requires at least one accessible means of egress. Where two or more means of egress are required for any space, at least two accessible means of egress are required for that space (IBC 1009.1). There are several exceptions for existing buildings, mezzanines and assembly areas with seating areas served by aisles.
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There is no code requirement for more than two accessible means of egress to serve any space.

Required Means of Egress: Where Required
The number of means of egress required from any space is governed by one of the following sections:

1006.2. If the number of occupants in a room or space or the common path of egress travel exceeds the value listed in Table 1006.2.1, two means of egress are required.

1006.3. Generally, all stories require at least two means of egress. If the story contains more than 500 occupants, the requirements increases to 3 means of egress, and increases again to a minimum of 4 when the story has an occupant load of more than 1,000.

The above code sections contain numerous exceptions, so be sure to review for your specific situation.