Category: Building Codes

IMPORTANT DISCLAIMER: This guide references NFPA 101, Life Safety Code (2024 edition: Section 7.15 on Occupant Evacuation Elevators; Section 7.14 on Elevators for Occupant-Controlled Evacuation Prior to Phase I Emergency Recall Operations); the International Building Code (IBC), Section 3008 (Occupant Evacuation Elevators), Section 3007 (Fire Service Access Elevators), and Section 403.5.2 (additional stairway / OEE alternative); ASME A17.1/CSA B44, Safety Code for Elevators and Escalators (§2.27.10 on Occupant Evacuation Operation); and NFPA 72, National Fire Alarm and Signaling Code (§21.6 on Occupant Evacuation Elevators). These codes vary significantly by edition and are frequently amended by state and local jurisdictions. NFPA 101 editions include 2012, 2015, 2018, 2021, and 2024. Section numbers for OEE have shifted between editions — NFPA 101 §7.15 (2024) is the current OEE provision. The most recent published edition is NFPA 101 (2024), but AHJ-adopted editions commonly lag behind by one or more cycles. IBC Section 3008 and ASME A17.1 §2.27.10 requirements have evolved across editions — verify specific requirements against your AHJ-adopted edition. Local amendments and the edition adopted by your Authority Having Jurisdiction (AHJ) always control. This guide is a starting point only. Always verify the specific requirements applicable to your project with your local AHJ.

The message “In case of fire, use stairs — do not use elevators” has been a fixture of fire safety education for decades. And for good reason: standard elevators can open onto a fire floor, become trapped by smoke, or lose power. But since the 2013 edition of ASME A17.1/CSA B44, a new category of elevator exists: the occupant evacuation elevator (OEE).

These elevators are designed, protected, and operated specifically to allow building occupants to evacuate during a fire. They are not a replacement for stairs. They are an additional egress option—particularly valuable for occupants who cannot use stairs, and for high-rise buildings where stair evacuation can take significantly longer.

This article covers the regulatory framework, design requirements, and operational considerations for occupant evacuation elevators.

◆ Section 1: Why Evacuation Elevators Are Different

An occupant evacuation elevator is not a standard elevator with a sticker on it. It is a system of systems—elevator equipment, shaft construction, lobby protection, power supply, fire alarm interface, and operational procedures—designed to keep the elevator safe for use during a fire.

Key point: Occupant evacuation elevators are permitted, not required. A building can choose to provide them, typically to satisfy the additional stairway requirement in buildings exceeding 420 feet in height, measured from the lowest level of fire department vehicle access to the highest occupied floor (IBC §403.5.2).

Pro Tip: The requirements are found in NFPA 101 §7.15 (2024), IBC §3008, and ASME A17.1/CSA B44 §2.27.10. All three must be satisfied.

◆ Section 2: Regulatory Framework

Evacuation elevator design is governed by a coordinated set of codes and standards.

Key point: The elevator code (ASME A17.1) defines how the elevator operates during OEO. The building code (IBC) and life safety code (NFPA 101) define what protections must be in place. NFPA 72 §21.6 defines the fire alarm interface.

Note on NFPA 101 §7.14: This section covers occupant-controlled evacuation prior to Phase I recall—a different concept from OEO. OEO is the coordinated, fire-alarm-initiated evacuation operation defined in ASME A17.1.

OEE vs. Fire Service Access Elevators (FSAE)

Readers often confuse occupant evacuation elevators (OEE) with fire service access elevators (FSAE). They serve different purposes :

Pro Tip: A building can have elevators equipped for occupant evacuation without using them for that purpose on every alarm. The OEO function activates only when the fire alarm system signals an evacuation zone, or when manually initiated.

◆ Section 3: Occupant Evacuation Operation (OEO)

OEO is the mode of elevator operation that moves occupants from the fire floor to a safe discharge level.

A. Activation

OEO is initiated by the fire alarm system. Upon activation of an automatic fire alarm initiating device in any area which does not initiate Phase I recall in this group, the fire alarm system provides signals to the elevator system indicating the floors to be evacuated.

Clarification: Devices in the elevator lobby, machine room, or hoistway initiate Phase I recall instead of OEO. Devices in other areas initiate OEO.

The evacuation zone is a contiguous block of floors: at least the floor with an active alarm, two floors above and two floors below.

If additional alarms occur on other floors while OEO is in effect, the evacuation zone expands to include all floors between the highest and lowest alarm, plus two floors above and below.

Exception: If the active alarm is on the elevator discharge level, automatic OEO initiation is not permitted. Manual initiation by authorized personnel is permitted.

B. Operation Sequence

When OEO actuates, the elevators follow a specific sequence :

C. Termination

OEO terminates when the fire alarm system is reset or when Phase I recall signals are actuated.

Key point: OEO is designed to function prior to Firefighters’ Emergency Operation (FEO). If firefighters need the elevators, they can initiate Phase I recall to take control.

Pro Tip: A “GROUP FIRE RECALL” switch in the designated level lobby and a switch in the fire command center allow firefighters to recall all elevators in a group. Individual “CAR FIRE RECALL” switches allow recall of specific cars while leaving others available for OEO. Verify the exact switch configurations against ASME A17.1 §2.27.10 for your adopted edition.

◆ Section 4: Protection Requirements

For an elevator to be used for occupant evacuation, specific protection features must be in place.

A. Elevator Type Restrictions

IBC §3008.1.1 prohibits all freight elevators and all hydraulic elevators from use for occupant self-evacuation. NFPA 101 §7.15.6.3 (2024) separately limits OEE to electric passenger elevators in noncombustible hoistways.

B. Hoistway Enclosure

The elevator hoistway must be enclosed in 2-hour fire-resistance-rated construction.

C. Machine Room and Control Space

Elevator machine rooms and control spaces must be separated from other building spaces by 2-hour fire-resistance-rated construction.

D. Machine Room Protection

The machine room is protected by:

• The 2-hour fire-resistance-rated enclosure

• Fire detection in the machine room, which triggers Phase I recall and alerts the fire command center (per NFPA 72 §21.6)

Separately, the following are prohibited:

• Sprinklers in elevator machine rooms and machine spaces for occupant evacuation elevators (NFPA 101 §7.15.5.2, 2024). This is because the elevator code requires shunt trip when sprinklers are installed, and shunt trip would abruptly disable the elevators upon heat sensing—potentially trapping occupants.

• Shunt trip for all occupant evacuation elevators (NFPA 101 §7.15.5.6.2, 2024).

E. Occupant Evacuation Shaft System

The occupant evacuation shaft system provides the building construction features that support the elevator system. Key concepts include :

• The elevator hoistway must be served at each floor by an elevator lobby meeting specific requirements

• The shaft system must protect the elevators from fire effects for the time period during which occupants are evacuating

F. Lobby Requirements

Each occupant evacuation elevator lobby must have a minimum floor area that accommodates :

1. 3 square feet per person for not less than 25 percent of the occupant load of the floor area served

2. One wheelchair space of 30 inches by 48 inches for each 50 persons of occupant load

Lobby enclosure: The lobby must be enclosed by a smoke barrier with 1-hour fire resistance rating.

Direct access to stair: Each lobby must have direct access to an interior exit stairway or ramp (IBC §3008; verify specific subsection against your adopted edition).

Lobby doors must be automatic-closing and must close in response to any alarm signal initiated on that floor.

Water protection: Elevator lobby doors must have an automatic positioning bottom seal to resist the passage of water at floor level from outside the shaft system.

G. Electrical Power

◆ Section 5: Fire Alarm and Communication Interface

The occupant evacuation elevator system requires extensive interface with the fire alarm and communication systems.

A. Fire Alarm System Interface

The fire alarm system must provide signals to the elevator system indicating the floors to be evacuated, as described in Section 3.

The fire alarm system must also provide a means to initiate total building evacuation labeled “ELEVATOR TOTAL BUILDING EVACUATION” at the fire command center.

B. Variable Message Signs

A sign reading “In case of fire, elevators are out of service” is not permitted on occupant evacuation elevator landings. The standard sign required by ASME A17.1 §2.27.9 shall not be installed. Instead, a variable message sign must be installed for each elevator group on each landing served.

The sign must be located not less than 84 inches and not more than 120 inches above the floor, in a central visible location within the elevator lobby. Message text must be a minimum of 2 inches high.

Messages must indicate:

• On floors being evacuated: elevators available for evacuation, estimated time for next car

• On floors not being evacuated: elevator service not available

• On discharge level: cars in evacuation mode, passengers should not use elevators

• If no elevators available: use stairs

C. Two-Way Communication

A two-way communication system must be provided in each occupant evacuation elevator lobby for the purpose of initiating communication with the fire command center or an alternate approved location. Verify the applicable IBC subsection against your adopted edition.

D. Emergency Voice/Alarm Communication System

The building must be provided with an emergency voice/alarm communication system accessible to the fire department. No fewer than one audible and one visible notification appliance must be installed within each occupant evacuation elevator lobby.

E. Elevator System Monitoring

The occupant evacuation elevators must be continuously monitored at the fire command center or a central control point approved by the fire department. The monitoring must display :

1. Floor location of each car

2. Direction of travel of each car

3. Status of each car with respect to whether it is occupied

4. Status of normal power to elevator equipment

5. Status of emergency power system

6. Activation of any fire alarm initiating device in any elevator lobby, machine room, or hoistway

◆ Section 6: Signage and Occupant Information

Signage is critical for occupant evacuation elevators because occupants must understand that these elevators are safe to use.

Signage requirement: An approved sign indicating elevators are suitable for occupant self-evacuation must be posted on all floors adjacent to each elevator call station serving occupant evacuation elevators.

The variable message sign requirements are described in Section 5B.

Key point: The signage and messaging must be clear and unambiguous. Occupants who see “elevators available for evacuation” must be able to trust that message.

Pro Tip: The variable message signs must be powered by the same power supply as the elevator, including emergency or standby power. They must remain operational when the elevators are operational.

◆ Section 7: Operational Considerations and Training

Evacuation elevators are not self-operating. They require trained staff and coordination with the fire service.

A. Building Staff Roles

Building staff—typically the fire safety director or facility management team—must understand how OEO works, how to monitor the system from the fire command center, and how to communicate with occupants.

The fire command center displays the status of each elevator car, the activation of fire alarm devices, and the status of normal and standby power. Staff must be trained to interpret this information.

B. Fire Safety and Evacuation Plan

The IBC requires the building to have a fire safety and evacuation plan that incorporates specific procedures for occupants using evacuation elevators. Verify the applicable IBC subsection against your adopted edition.

C. Fire Service Coordination

The fire service must understand that the building has occupant evacuation elevators and how to interact with them. The Group Fire Recall and Car Fire Recall switches allow firefighters to take control of some or all elevators as needed.

When firefighters initiate Phase I recall, OEO is terminated for the recalled cars.

D. Drills

Evacuation drills in buildings with occupant evacuation elevators should include scenarios where OEO is used. Staff should practice:

• Monitoring the fire command center during an OEO event

• Communicating with occupants in elevator lobbies

• Coordinating with the fire service if they arrive during OEO

Key Article: Article 130 — Emergency Action Plans and Evacuation Drills (upcoming)

Key point: Occupant evacuation elevators are a tool, not a replacement for training. Staff must know how the system operates and what their role is during an evacuation.

Pro Tip: The best time to test OEO is during a scheduled drill—not during a real emergency. Conduct drills that exercise the OEO function and the staff procedures that support it.

◆ Section 8: Accessible Means of Egress

Occupant evacuation elevators may, where permitted by IBC §1009, serve as a component of an accessible means of egress. The applicability depends on whether the building is sprinklered, the number of stories above or below the level of exit discharge, and the applicable exceptions. Where the conditions of IBC §1009 are met, OEE may satisfy the accessible means of egress requirement that would otherwise require an area of refuge at an exit stairway.

Key Article: Article 122 — Areas of Refuge and Stairwell Reentry

Verify the specific IBC §1009 provisions and exceptions against your adopted edition.

◆ Section 9: Design Checklist for Occupant Evacuation Elevators

◆ Section 10: Common Mistakes and How to Avoid Them

◆ Section 11: Conclusion

Occupant evacuation elevators represent a significant evolution in high-rise evacuation strategy. They are not a replacement for stairs—they are an additional egress option, particularly valuable for occupants who cannot use stairs and for buildings where stair evacuation can take significantly longer.

But they are also complex systems that require coordinated design, protection, and operation. The hoistway must be protected. The lobby must be sized and protected. The power supply must be reliable. The fire alarm system must interface correctly. And staff must know how to monitor and operate the system.

Key Takeaways:

1. Occupant evacuation elevators are permitted, not required—they are an additional egress option.

2. The regulatory framework is coordinated: NFPA 101 §7.15 (2024), IBC §3008, ASME A17.1 §2.27.10, and NFPA 72 §21.6.

3. OEO activates when the fire alarm system signals an evacuation zone—a contiguous block of floors including the alarm floor, two above, and two below.

4. Freight and hydraulic elevators are prohibited from use for occupant self-evacuation (IBC §3008.1.1).

5. Hoistway and machine room must be 2-hour rated; sprinklers and shunt trip are prohibited in machine rooms (NFPA 101 §7.15.5.2 and §7.15.5.6.2, 2024).

6. Lobby size must accommodate 3 sq ft/person for 25% of occupant load plus wheelchair spaces.

7. Lobby enclosure is a 1-hour smoke barrier; direct access to an exit stair is required.

8. Lobby doors must be automatic-closing and close on floor alarm.

9. Standby power must operate all elevators simultaneously; feeders in 2-hour rated enclosures.

10. Variable message signs replace standard fire-service signage; located 84–120 inches above floor with 2-inch text.

11. Two-way communication and emergency voice/alarm communication required in each lobby.

12. Elevator system monitoring at fire command center displays car location, direction, occupancy, and power status.

13. Group Fire Recall and Car Fire Recall switches allow firefighters to take control as needed.

14. Fire safety and evacuation plan must incorporate OEE procedures.

Take Action Today:

1. Determine whether your building has or will have occupant evacuation elevators.

2. Verify compliance with NFPA 101 §7.15 (2024), IBC §3008, and ASME A17.1 §2.27.10.

3. Confirm hoistway and machine room 2-hour ratings.

4. Verify sprinklers and shunt trip are prohibited in machine rooms.

5. Confirm lobby size meets 3 sq ft/person and wheelchair space requirements.

6. Verify lobby has direct access to an exit stair and is enclosed by a 1-hour smoke barrier.

7. Verify variable message signs are installed and operational.

8. Confirm two-way communication and emergency voice/alarm systems are in place.

9. Verify elevator monitoring at fire command center.

10. Develop fire safety and evacuation plan incorporating OEE procedures.

11. Train staff on OEO monitoring and occupant communication.

12. Coordinate with fire service on Group/Car Fire Recall procedures.

Continue Reading from Our Series:

• Related guide: Areas of Refuge and Stairwell Reentry

• Learn more: Exit Access, Exit, and Exit Discharge Explained

• Read more: How to Design for Fire Safety in High-Rise Buildings

IMPORTANT DISCLAIMER: This guide references NFPA 101, Life Safety Code (Chapter 3 for definitions of exit access, exit, and exit discharge; Chapter 7, Means of Egress, specifically §7.6 on measurement of travel distance; and Chapters 12–42 for occupancy-specific travel distance limits); and the International Building Code (IBC), §202 for definitions, Chapter 10 (Means of Egress), approximately §1003–§1033 in current editions, §1019 on exit access stairways, §1020.2 on corridor width and capacity (verify against your adopted edition), and Table 1017.2 for travel distance limits. These codes vary significantly by edition and are frequently amended by state and local jurisdictions. NFPA 101 editions include 2018, 2021, and 2024. 2024 is the latest edition I could confirm; check whether the 2027 edition has been issued. The most recently confirmed published edition is NFPA 101 (2024), but AHJ-adopted editions commonly lag behind by one or more cycles. Section numbers for means of egress components have shifted between editions — verify specific requirements against your AHJ-adopted edition. Local amendments and the edition adopted by your Authority Having Jurisdiction (AHJ) always control. This guide is a starting point only. Always verify the specific requirements applicable to your project with your local AHJ.

The terms “exit,” “exit access,” and “exit discharge” are often used interchangeably in everyday conversation. But in NFPA 101 and the IBC, they describe three distinct components of the means of egress—each with its own definition, its own protection requirements, and its own travel distance limits.

Confusing these components is a frequent source of review comments. A corridor is not an exit. A stairway is not an exit discharge. And travel distance limits apply to the exit access, not to the exit itself.

This article explains the distinction between the three components, the requirements that apply to each, and the common areas of confusion that lead to violations.

◆ Section 1: The Three Components of Means of Egress

NFPA 101 and the IBC define the means of egress as a continuous and unobstructed path of vertical and horizontal travel from any occupied portion of a building to a public way. That path consists of three parts:

Key point: The means of egress is a system. Each component has a different level of protection, and the protection level must not be reduced until the occupant reaches the exit discharge.

Pro Tip: The simplest way to remember the three components: Exit access is where you are; the exit is where you go; the exit discharge is where you end up.

◆ Section 2: Exit Access

The exit access is the portion of the means of egress that leads to an exit. It may or may not be fire-rated—a 1-hour rated corridor is still exit access.

A. What Constitutes Exit Access

Exit access includes:

• Areas between desks, rows, and aisles in an office building

• Corridors in all building types

• Space in individual dwellings

• Concourses in airports, stadia, and malls

B. Travel Distance Limits

Travel distance limits apply to the exit access portion of the means of egress. Once an occupant reaches an exit (such as an enclosed exit stairway), the travel distance limit no longer applies to that portion of the path.

Travel distance is measured along the centerline of the natural path of travel, starting from the most remote point subject to occupancy, curving around corners or obstructions with a 12-inch (305 mm) clearance, and ending at the center of the doorway or other point at which the exit begins.

Key Article: Article 37 — Travel Distance Limits by Occupancy Type

Note on travel distance limits: NFPA 101 §7.6 covers the measurement of travel distance; the actual numerical limits are in the occupancy chapters (Chapters 12–42). For the IBC, the limits are in Table 1017.2.

C. Common Path of Travel

The common path of travel is the portion of the exit access that must be traveled before two separate and distinct paths of travel to two exits are available. It is measured in the same manner as travel distance, but terminates at the point where two separate and distinct paths become available.

Key point: Exit access travel distance terminates when the occupant reaches an exit. An exit access stairway is a stairway within the exit access, which may be open or enclosed (IBC §1019) but is not an exit. Travel on that stair counts toward the exit access travel distance.

Pro Tip: An exit access stair is part of the exit access, so it does not provide the protected path of an exit stair, and its use is limited by code (see IBC §1019).

◆ Section 3: Exit

The exit is the portion of the means of egress that is typically separated from other interior spaces by fire-resistance-rated construction and opening protectives. It provides a protected path between the exit access and the exit discharge.

A. What Constitutes an Exit

NFPA 101 and the IBC recognize several types of exits:

B. Protection Requirements

Once an occupant reaches an exit, they are provided with an established degree of protection from fire and smoke. That protection level must not be reduced until arrival at the exit discharge.

Key point: The protected, code-compliant separation (typically rated construction) is what distinguishes an exit from exit access.

Pro Tip: An exit passageway is often overlooked. It is a horizontal component of an exit—not a corridor—and must meet the same protection requirements as an exit stairway enclosure. A rated corridor is not an exit passageway.

◆ Section 4: Exit Discharge

The exit discharge is the portion of the means of egress between the termination of an exit and a public way.

A. What Constitutes Exit Discharge

Exit discharge includes driveways, yards, courts, parking lots, and other paths leading to a public way. A public way is a street, alley, or other parcel dedicated for public use that is open to the outside air and at least 10 feet (3 m) wide and high.

B. Protection Requirements

The exit discharge must lead to a free and unobstructed way to the exterior of the building, and that way must be readily visible and identifiable from the point of discharge from the exit.

When exits discharge through the level of exit discharge (interior discharge): The level of discharge must be protected throughout by an approved automatic sprinkler system, or the portion of the level of discharge used for discharge must be sprinklered and separated from the nonsprinklered portion by fire-resistance-rated construction. This permission is limited—typically to no more than 50 percent of the required exits and capacity.

Exceptions: A vestibule or foyer meeting specific criteria (depth not more than 10 feet, length not more than 30 feet, separated from the remainder of the level of discharge, serving only as means of egress) is exempt from the separation requirement for interior discharge.

C. Marking and Arrangement

The exit discharge must be arranged and marked to make clear the direction of egress to a public way. Stairs that continue more than one-half story beyond the level of exit discharge must be interrupted by partitions, doors, or other effective means.

The exit discharge must not re-enter a building (IBC §1028.1). Verify the NFPA 101 equivalent in your adopted edition.

Key point: The exit discharge is not just the door at the bottom of the stairs. It is the entire path from the exit to the public way—and it must be protected, visible, clearly marked, and must not re-enter a building.

Pro Tip: A frequent exit discharge problem is a path that is not readily visible from the exit door. Landscaping, parking, or building features that obscure the path to the public way create a code violation.

◆ Section 5: Travel Distance in Each Component

Travel distance limits apply differently to each component.

Key point: The travel distance limit is a design constraint on the exit access. Once the occupant reaches the exit, the code assumes they are in a protected environment and no longer subject to the travel distance limit.

Pro Tip: If your exit access travel distance is too long, adding an exit (such as an enclosed stairway or horizontal exit) can terminate the travel distance measurement earlier. This is often more practical than trying to shorten the path.

◆ Section 6: Common Areas of Confusion

Several common misconceptions lead to code violations.

A. “The Corridor Is the Exit”

The corridor is part of the exit access, not the exit. The exit begins at the point where the occupant enters an exit meeting the code’s exit requirements—typically at the door into an interior exit stairway enclosure or an exit passageway.

B. “The Stairway Is the Exit Discharge”

The stairway is an exit, not the exit discharge. The exit discharge begins when the occupant leaves the exit—typically at the door at the bottom of the stairway—and continues to the public way.

C. Travel Distance Includes the Enclosed Exit Stairs

Travel distance is measured on the exit access, not within the enclosed exit stairs. Once the occupant enters the enclosed stairway, travel distance measurement stops.

Note: This differs from exit access stairs. An exit access stair is part of the exit access, so travel on an exit access stair does count toward exit access travel distance.

D. “An Exit Access Stair Is an Exit”

An exit access stair is a stairway within the exit access, which may be open or enclosed (IBC §1019) but is not an exit. Travel on it counts toward exit access travel distance. Use of exit access stairs is limited by code (IBC §1019).

Key point: The boundary between exit access and exit is the point of entry into a code-compliant exit (enclosure, passageway, or exterior exit door). A rated corridor does not become an exit just because it is rated.

Pro Tip: When reviewing plans, ask: “Where does the occupant enter a code-compliant exit?” The answer is the boundary between exit access and exit.

◆ Section 7: Design Checklist for Means of Egress Components

◆ Section 8: Common Mistakes and How to Avoid Them

◆ Section 9: Conclusion

The means of egress is a system of three distinct components: exit access, exit, and exit discharge. Each has its own definition, its own protection requirements, and its own travel distance limits.

Understanding the distinction is not academic—it determines where travel distance is measured, where protection is required, and what constitutes a code violation.

Key Takeaways:

1. The means of egress has three components: exit access, exit, and exit discharge.

2. Exit access is the portion leading to an exit—corridors, aisles, open stairs. It may or may not be fire-rated.

3. Exit is the protected portion—enclosed stairways, exit passageways, exterior doors. It is typically separated by fire-resistance-rated construction.

4. Exit discharge is the portion between the exit and a public way. The public way must be open to the outside air.

5. Travel distance limits apply to exit access only—not to the exit or exit discharge.

6. Exit protection must not be reduced until arrival at the exit discharge.

7. Exit discharge must be free, unobstructed, visible, clearly marked, and must not re-enter a building (IBC §1028.1).

8. When exits discharge through the level of exit discharge, the sprinkler/separation requirement applies, and is typically limited to 50% of required exits and capacity.

9. Stairs continuing beyond the level of discharge must be interrupted.

10. An exit access stair is not an exit—it is part of the exit access, may be open or enclosed (IBC §1019), and its use is limited by code.

11. The boundary between exit access and exit is the point of entry into a code-compliant exit (enclosure, passageway, or exterior exit door).

Take Action Today:

1. Identify the three components on your life safety plans.

2. Verify travel distance is measured to the exit, not within enclosed exit stairs.

3. Confirm exit protection is continuous and not reduced.

4. Verify exit discharge is visible, marked, and protected.

5. Confirm exit discharge does not re-enter the building (IBC §1028.1).

6. Check that stairs beyond the level of discharge are interrupted.

7. Confirm exit access stairs are not treated as exits; verify code limits on their use (IBC §1019).

8. Verify exit passageways meet exit protection requirements.

Continue Reading from Our Series:

• Related guide: Travel Distance Limits by Occupancy Type

• Learn more: How to Know How Many Exits Are Required (NFPA 101 Table 7.4)

• Read more: Areas of Refuge and Stairwell Reentry

IMPORTANT DISCLAIMER: This guide references NFPA 101, Life Safety Code (Chapter 7, Means of Egress, specifically §7.2.12 on Areas of Refuge, §7.5.4 on Accessible Means of Egress, and §7.2.1.5.8 on Stairwell Reentry); the International Building Code (IBC), Section 1009 (Accessible Means of Egress — note that in the 2015 IBC this was Section 1007, and from 2018 onward it is Section 1009); and the ADA Standards for Accessible Design. These codes vary significantly by edition and are frequently amended by state and local jurisdictions. NFPA 101 editions include 2018, 2021, 2024, and 2027 (current). The most recent published edition is NFPA 101 (2027), but AHJ-adopted editions commonly lag behind by one or more cycles. Section numbers for areas of refuge and stairwell reentry have shifted between editions — verify specific requirements against your AHJ-adopted edition. Local amendments and the edition adopted by your Authority Having Jurisdiction (AHJ) always control. This guide is a starting point only. Always verify the specific requirements applicable to your project with your local AHJ.

Not every occupant can use a stairway. People who use wheelchairs, those with mobility impairments, and others who cannot negotiate stairs need an alternative path to safety. Areas of refuge provide that path—a temporary safe space where occupants can wait for assistance or use an elevator as part of an accessible means of egress.

Stairwell reentry serves a different but related purpose. It allows occupants to leave a stairwell and re-enter a floor if the stairwell becomes untenable, or if they entered the stairwell and discovered they cannot continue down. Together, areas of refuge and stairwell reentry make buildings usable by all occupants—not just those who can walk down stairs unaided.

This article covers the design requirements for both under NFPA 101 and the IBC.

◆ Section 1: What Areas of Refuge Are

An area of refuge is a space where occupants who cannot use stairs can wait for assistance or use an elevator as part of an accessible means of egress. It is not a destination—it is a temporary safe space within the building.

Key point: An area of refuge is a component of an accessible means of egress. It must connect to an accessible route that continues to a public way or another area of refuge.

Key Article: Article 121 — Horizontal Exits: Design, Rating, and Use Cases

Pro Tip: Areas of refuge are required at accessible exit stairways and elevator access serving floors above or below the level of exit discharge, unless an exception applies. Fully sprinklered buildings are exempt from providing areas of refuge at exit stairways under the IBC (IBC §1009.3, exceptions). Verify the exceptions against your adopted edition. NFPA 101 treats this differently.

◆ Section 2: When Areas of Refuge Are Required

The requirement for areas of refuge comes from the accessible means of egress provisions.

A. General Requirement

Where a floor is accessible and is four or more stories above or below the level of exit discharge, at least one elevator must be provided to comply with the accessible means of egress requirements. That elevator must be accessed from an accessible area of refuge or an elevator lobby meeting the elevator lobby provisions (IBC §713.14 in recent editions). The elevator must comply with ASME A17.1 emergency operation, which includes standby power.

B. Stairway Access

An exit stair, to be considered part of an accessible means of egress, must have stair flights and landings with a minimum clear width of 48 inches between handrails (with sprinklered-building exception) and must either incorporate an accessible area of refuge within an enlarged story-level landing or be accessed from an accessible area of refuge.

C. Exterior Areas for Assisted Rescue

Where the exit discharge is not accessible, an exterior area for assisted rescue must be provided. These areas are subject to specific requirements for separation, openness, and stairway width.

Key point: The requirement for areas of refuge is tied to the accessible means of egress provisions, not to a standalone mandate. If a building is not required to provide an accessible means of egress, areas of refuge may not be required.

Pro Tip: Verify the applicable accessible means of egress requirements against your adopted edition. The IBC and NFPA 101 have different thresholds and exceptions.

◆ Section 3: Design Requirements for Areas of Refuge

Areas of refuge must meet specific requirements for size, separation, and access.

A. Size

Each area of refuge must be sized to accommodate one wheelchair space of 30 inches by 48 inches (762 mm by 1219 mm) for each 200 occupants or portion thereof, based on the occupant load of the area of refuge and areas served by the area of refuge.

Wheelchair spaces must not reduce the required means of egress width. Access to any required wheelchair space must not be obstructed by more than one adjoining wheelchair space.

B. Separation

Each area of refuge must be separated from the remainder of the story by a smoke barrier complying with the building code or a horizontal exit complying with Section 1026. Each area of refuge must be designed to minimize the intrusion of smoke.

Exception: Areas of refuge located within a vertical exit enclosure (stairway) are exempt from the smoke barrier requirement.

C. Access and Travel Distance

Every required area of refuge must have direct access to an enclosed stairway or an elevator complying with the accessible means of egress provisions.

The maximum travel distance from any accessible space to an area of refuge shall not exceed the exit access travel distance permitted by the code.

Where an elevator lobby is used as an area of refuge, the shaft and lobby must comply with smokeproof enclosure requirements, except where the elevators are in an area of refuge formed by a horizontal exit or smoke barrier.

Key point: The 30-inch by 48-inch wheelchair space is per 200 occupants. This is an assumption that one person using a wheelchair will be present per 200 occupants.

Pro Tip: The area of refuge must be accessible from the space it serves by an accessible means of egress. Verify the accessible route is continuous and that travel distance is within limits.

◆ Section 4: Two-Way Communication

Two-way communication is a required feature of areas of refuge.

A. System Requirements

Areas of refuge must be provided with a two-way communication system between the area of refuge and a central control point. If the central control point is not constantly attended, the area of refuge must also have controlled access to a public telephone system.

The location of the central control point must be approved by the fire department.

The two-way communication system must include both audible and visible signals.

B. Power and Backup

The two-way communication system must have a battery backup or approved alternate source of power capable of 90 minutes’ use upon failure of the normal power source. Verify this requirement against your AHJ-adopted edition. NFPA 72 Chapter 24 governs these systems.

C. Testing

All two-way communication systems must be tested in the presence of the code official upon completion of installation. Communication systems must be inspected and tested in accordance with NFPA 72 to verify all components are operational.

D. Instructions

Instructions on the use of the area under emergency conditions must be posted adjoining the communications system. The instructions must include:

1. Directions to find other means of egress.

2. Persons able to use the exit stairway do so as soon as possible, unless they are assisting others.

3. Information on planned availability of assistance in the use of stairs or supervised operation of elevators and how to summon such assistance.

4. Directions for use of the emergency communications system.

Key point: The two-way communication system is not optional. It is a required component of the area of refuge and must be tested and maintained.

Pro Tip: Instructions must be posted adjacent to the communication system. Without them, occupants may not know how to use the system or may incorrectly remain in the area of refuge when they are able to continue egress.

◆ Section 5: Signage and Identification

Areas of refuge must be identified with specific signage.

A. Sign Requirements

Each door providing access to an area of refuge from an adjacent floor area must be identified by a sign stating “AREA OF REFUGE” and including the International Symbol of Accessibility.

The sign must comply with ICC A117.1 requirements for visual characters.

Where exit sign illumination is required, the area of refuge sign must be illuminated.

Tactile signage complying with ICC A117.1 must be located at each door to an area of refuge.

B. Directional Signage

At exits and elevators serving a required accessible space but not providing an approved accessible means of egress, signage must be installed indicating the location of accessible means of egress.

Key point: The signage must be visible, illuminated where required, and include tactile elements for accessibility.

Pro Tip: Directional signs must also be provided to clearly indicate the direction to areas of refuge where necessary.

◆ Section 6: Stairwell Reentry

Stairwell reentry allows occupants to leave a stairwell and re-enter a floor.

A. Purpose

Stairwell reentry serves two purposes: it allows occupants to exit a compromised stairwell, and it provides emergency responders access to upper floors. This dual function makes reentry a critical part of life safety planning.

B. Code Requirements

Reentry provisions apply to stairs serving more than four stories.

Stair doors must either permit reentry at every floor or use selected reentry.

Selected reentry has conditions: no more than four stories between reentry doors, at least two reentry levels, and reentry at the top or next-to-top story.

A stair-side lock is acceptable only if it automatically unlocks on a fire alarm signal.

For stairs serving four stories or fewer, doors may remain locked from the stair side. Verify against the adopted edition. Healthcare and detention occupancies follow their own occupancy chapters.

IBC requirements: Interior stairway means of egress doors shall be openable from both sides without the use of a key or special knowledge or effort. Exceptions allow locking on the stair side in stairs serving four stories or fewer, with simultaneous unlocking from the fire command center. Verify the section number against your adopted edition — the number has shifted between editions.

C. Signage

Where provisions for stairwell reentry are used, signage on the stair door leaves is required:

1. Door assemblies allowing re-entry must be identified as such on the stair side of the door leaf.

2. Door assemblies not allowing re-entry must be provided with a sign on the stair side indicating the location of the nearest door opening, in each direction of travel, that allows re-entry or exit.

If a stair enclosure allows access to the roof, the door to the roof must either be kept locked or allow re-entry from the roof.

Key point: Stairwell reentry is about allowing occupants to enter a floor from the stairwell, not about restricting access into the stairwell.

Pro Tip: Verify the reentry provisions against your adopted edition. The requirements have evolved, and AHJ interpretation varies.

◆ Section 7: Hardware and Egress Considerations

The hardware on stairwell doors must meet specific requirements.

A. Fail-Safe vs. Fail-Secure

Fail-safe locks, which unlock during power loss or alarm activation, are generally required where electrified locking is used on the stair side for reentry control. Fail-secure hardware is permitted where free mechanical egress is always maintained, as with a panic device on the egress side. Where electrified locking is used on the stair side for reentry control, it must release on fire alarm or power loss.

B. Electric Strikes

Electric strikes are permitted where listed for use on fire door assemblies, where the hardware maintains positive latching under NFPA 80, and where the hardware does not impede free egress.

C. Pressurization Considerations

Stairwells are pressurized to keep smoke out. Design basis: Pressure differentials vary with ceiling height and application — verify the specific figures in IBC §909 and NFPA 92 for your project. Under NFPA 101, the door-opening force limits are:

• 15 lbf to release the latch

• 30 lbf to set the door in motion

• 15 lbf to open the door to the minimum required width

The 1.0 m/s (200 fpm) open-door air velocity applies to specific stair pressurization design scenarios — verify the applicable context in NFPA 92.

Fire doors must function under pressure and pass annual inspections covering seals, latching, and system compliance.

Key point: The door hardware must operate without the need for prior knowledge or specialized training, allowing immediate and intuitive use during an emergency.

Pro Tip: Verify that the door hardware can be operated under the pressure differential created by stairwell pressurization. This is a common design challenge in high-rise buildings.

◆ Section 8: Design Checklist for Areas of Refuge and Stairwell Reentry

◆ Section 9: Common Mistakes and How to Avoid Them

◆ Section 10: Conclusion

Areas of refuge and stairwell reentry are critical components of accessible means of egress and occupant safety in buildings where not everyone can use stairs. Areas of refuge provide temporary safe spaces; stairwell reentry provides a way out of a compromised stairwell.

Key Takeaways:

1. An area of refuge is a temporary safe space for occupants who cannot use stairs.

2. Areas of refuge are required at accessible exit stairways and elevator access serving floors above or below the level of exit discharge, unless an exception applies.

3. Fully sprinklered buildings are exempt from providing areas of refuge at exit stairways under the IBC — NFPA 101 treats this differently.

4. Size: 30 in. × 48 in. wheelchair space per 200 occupants.

5. Separation: smoke barrier (1-hour) or horizontal exit (2-hour).

6. Two-way communication is required with audible and visible signals, 90-minute battery backup.

7. Instructions must be posted adjoining the communications system.

8. Signage: “AREA OF REFUGE” with International Symbol of Accessibility, illuminated where required, with tactile elements.

9. Stairwell reentry allows occupants to leave a compromised stairwell and provides firefighter access.

10. Fail-safe locks are required where electrified locking is used; fail-secure is permitted where free mechanical egress is always maintained.

11. Electric strikes must be listed for fire door assemblies and maintain positive latching.

Take Action Today:

1. Verify whether areas of refuge are required for your building.

2. Check the sprinklered-building exemption (IBC §1009.3 exceptions).

3. Confirm area of refuge size meets the 30 in. × 48 in. per 200 occupants requirement.

4. Verify the area of refuge is separated by a smoke barrier or horizontal exit.

5. Confirm two-way communication system is installed and tested.

6. Verify 90-minute battery backup for the communication system.

7. Confirm instructions are posted adjacent to the communication system.

8. Verify signage meets ICC A117.1 and includes tactile elements.

9. Confirm stairwell reentry provisions comply with adopted code.

10. Verify electrified locking releases on fire alarm or power loss.

11. Test door hardware under stairwell pressurization conditions.

Continue Reading from Our Series:

• Related guide: Horizontal Exits: Design, Rating, and Use Cases

• Learn more: How to Design for Fire Safety in High-Rise Buildings

• Read more: Emergency Lighting and Exit Sign Requirements (NFPA 101)

IMPORTANT DISCLAIMER: This guide references NFPA 101, Life Safety Code (Chapter 7, Means of Egress, specifically §7.2.4 on Horizontal Exits; §7.2.1.7 on Panic Hardware and Fire Exit Hardware; §7.2.1.14 on Horizontal Sliding Doors; §7.4.1 on Number of Exits; §7.2.12 on Areas of Refuge; §9.6.2 on Manual Fire Alarm Boxes; and health care occupancy chapters 18 and 19 for hospitals, nursing homes, and limited care facilities; chapters 20 and 21 for ambulatory health care); NFPA 80, Standard for Fire Doors and Other Opening Protectives; NFPA 14, Standard for the Installation of Standpipe and Hose Systems; NFPA 72, National Fire Alarm and Signaling Code; and the International Building Code (IBC), Section 1026. These codes vary significantly by edition and are frequently amended by state and local jurisdictions. NFPA 101 editions include 2018, 2021, and 2024 (current). The most recent published edition is NFPA 101 (2024), but AHJ-adopted editions commonly lag behind by one or more cycles. NFPA 101 §7.2.4 has been revised across editions — verify specific requirements against your AHJ-adopted edition. Local amendments and the edition adopted by your Authority Having Jurisdiction (AHJ) always control. This guide is a starting point only. Always verify the specific requirements applicable to your project with your local AHJ.

Unique among the types of exits permitted by NFPA 101, the horizontal exit does not lead occupants out of the building. Instead, it moves them through a fire-rated separation from one area to another on approximately the same level. The concept is simple: create a safe refuge on the other side of a wall, and occupants never have to use a stairway or exit the building.

That simplicity is also the source of the horizontal exit’s fragility. The fire barrier must be complete and total—any opening that could permit the passage of smoke or heat must be sealed. The doors must be rated, self-closing, and properly maintained. And the refuge area must be large enough to hold the occupants who will use it.

This article covers the design requirements for horizontal exits under NFPA 101, with a focus on fire rating, door hardware, capacity, and the use cases where they provide life safety benefits.

◆ Section 1: What a Horizontal Exit Is

NFPA 101 defines a horizontal exit as a way of passage from one building to an area of refuge in another building on approximately the same level, or a way of passage through or around a fire barrier to an area of refuge on approximately the same level in the same building.

Key point: A horizontal exit is not a substitute for stairs or doors to the outside. It is an additional exit. Under the general rule (NFPA 101 §7.2.4.1), horizontal exits can provide up to 50 percent of the required egress capacity from a floor or area. In health care occupancies, the occupancy chapters (Chapters 18 and 19 for hospitals, nursing homes, and limited care facilities) permit horizontal exits to provide up to two-thirds of the total egress capacity, provided the capacity of the other exits is not reduced below one-third of that required for the entire area of the building (NFPA 101 §18-2.2.5 / §19-2.2.5 in the current numbering).

Scope note: Chapters 18 and 19 cover hospitals, nursing homes, and limited care facilities. Ambulatory health care is covered by Chapters 20 and 21.

Key Article: Article 44 — Subdivision of Building Spaces and Smoke Compartments (NFPA 101). Note that horizontal exits use fire barriers, not smoke barriers—the two serve different purposes and have different rating requirements.

Pro Tip: The horizontal exit is most valuable in occupancies where occupants cannot easily use stairs—hospitals, nursing homes, and other health care facilities—or in buildings where zoned evacuation is part of the emergency strategy.

◆ Section 2: Fire Resistance Rating Requirements

The fire barrier serving as a horizontal exit must provide a specific level of fire resistance.

A. The Basic Requirement

NFPA 101 §7.2.4 requires the fire barrier serving as a horizontal exit to have a fire resistance rating of at least 2 hours. The barrier must be constructed continuously from outside wall to outside wall through concealed spaces and extend through all levels, subject to the exception below.

B. Exterior Wall Intersection

Where the horizontal exit intersects with exterior walls at an angle of less than 180 degrees, the exterior wall must have a fire-resistance rating of at least 1 hour within 10 feet of the point of intersection, with openings protected by ¾-hour fire-rated opening protectives (NFPA 101 §7.2.4.3.4).

C. Termination at Lower Levels

The fire barrier serving as a horizontal exit does not need to continue beyond the lowest level to provide discharge to the exterior, provided the levels below are separated by construction with a fire-resistance rating of at least 2 hours and do not have a horizontal exit.

Key point: The 2-hour rating is not optional. A fire barrier with less than 2-hour rating cannot serve as a horizontal exit.

Pro Tip: Verify the fire barrier is continuous through concealed spaces. A barrier that stops at a suspended ceiling does not meet the requirement.

◆ Section 3: Door Requirements

The doors in a horizontal exit are the critical link between the two areas. They must be rated, self-closing, and properly arranged.

A. Fire Protection Rating

Doors in horizontal exits must have a minimum 1½-hour fire protection rating. Where the fire barrier is 2-hour rated, the doors must be at least 1½-hour rated.

B. Door Swing

Where swinging fire doors are used in horizontal exits, they must comply with the following:

• They must swing in the direction of egress travel.

• Where a horizontal exit serves areas on both sides of a fire barrier, there must be adjacent openings with swinging doors, opening in opposite directions, with signs on each side of the fire barrier indicating the door that swings with the travel from that side.

• Exception: Sleeping room areas in detention and correctional occupancies are exempt from the sign requirement.

Clarification on signage: Each side of the horizontal exit requires a sign identifying the door that swings in the direction of travel from that side.

C. Air Leakage

Doors in horizontal exits must be designed and installed to minimize air leakage.

D. Self-Closing or Automatic-Closing

All fire doors in horizontal exits must be self-closing or automatic-closing. Doors that are normally held open must be automatic-closing, actuated by detection or alarm activation.

E. Fire Exit Hardware

Fire-rated door assemblies may use ordinary lever or latch hardware where exit hardware is not required. However, where exit hardware is required or provided on a rated door, it must be fire exit hardware.

The primary distinction is the listing. Ordinary panic hardware is listed only to UL 305 (panic hardware performance). Fire exit hardware is additionally tested to UL 10C for fire performance. That additional listing is what makes it acceptable on a rated door.

A secondary concern is the dogging mechanism. Devices that hold the latch retracted are prohibited on fire exit hardware unless specifically listed for that purpose (NFPA 101 §7.2.1.7).

Key point: The rule is not that every rated door requires fire exit hardware. The rule is that where exit hardware is required or provided on a rated door, it must be fire exit hardware (NFPA 101 §7.2.1.7; NFPA 80).

Pro Tip: This is a common NFPA 80 fire door inspection finding. Verify hardware labels during annual inspections.

◆ Section 4: Capacity and Occupant Load

Horizontal exits can provide a portion of the required egress capacity, but not all of it.

A. Capacity Limit

No fire area shall be served only by horizontal exits.

Key point: Under the general rule, at least 50 percent of the required egress capacity must come from other exits. In health care occupancies, the other exits may be reduced to as little as one-third of the required capacity, leaving up to two-thirds for horizontal exits.

B. Refuge Area Size

The refuge area on each side of the horizontal exit must be large enough to accommodate its own occupants plus the occupants who will move into it from the adjoining compartment.

The aggregated area includes corridors, patient rooms, treatment rooms, lounge or dining areas, and other low hazard areas on each side of the horizontal exit.

Key point: The refuge area is not just the corridor. It includes the total low-hazard area on the refuge side of the barrier. Each side must accommodate its own occupants plus those who will move into it from the other side.

◆ Section 5: Door Clear Width

Horizontal exit doors must provide adequate clear width for the occupants who will use them.

Health care note: In health care occupancies, the occupancy chapters may require wider doors for bed movement. Verify the applicable requirements against your adopted edition.

Key point: The 32-inch minimum clear width applies to both swinging and horizontal sliding doors. Existing 34-inch doors are permitted as an exception.

Pro Tip: Verify the clear width after the door is installed, not just the nominal door size. Hardware, stops, and closers can reduce clear width.

◆ Section 6: Accessible Means of Egress

A horizontal exit can be a component of an accessible means of egress.

A. Requirements for Accessibility

A smoke barrier or horizontal exit, to be considered part of an accessible means of egress, must have a minimum 1-hour fire resistance rating and must discharge to an accessible area of refuge. Since a horizontal exit already has a minimum 2-hour rating, it exceeds the 1-hour minimum for accessible means of egress—there is no rating conflict.

B. Areas of Refuge

Each area of refuge must be separated from the remainder of the story by a smoke barrier with a minimum 1-hour fire resistance rating or a horizontal exit complying with §7.2.4. Verify the separation rating against NFPA 101 §7.2.12 for your adopted edition.

Key Article: Article 122 — Areas of Refuge and Stairwell Reentry (upcoming)

Pro Tip: Each area of refuge must be identified by a sign stating “AREA OF REFUGE” and displaying the international symbol of accessibility. Two-way communication must be provided.

◆ Section 7: When Horizontal Exits Are Used

Horizontal exits are not appropriate for every building. They are best suited for specific conditions.

Key point: A horizontal exit is often the most practical solution when a building needs additional egress capacity but cannot add stairways.

Pro Tip: A recent project involved a tenant space that needed a third exit for over 500 occupants (NFPA 101 §7.4.1 requires three exits for 501–1,000 occupants) but had only two existing stairs. A horizontal exit through a 2-hour separation solved the problem without adding a stair—subject to the 50 percent capacity limit.

◆ Section 8: Interface with Fire Alarm and Standpipe Systems

Horizontal exits interface with other building systems.

A. Manual Fire Alarm Boxes

Where manual fire alarm boxes are required, they must be located within 60 inches (1,525 mm) of exit doorways (NFPA 101 §9.6.2.3). At a horizontal exit, this means boxes on both sides of the barrier. NFPA 72 establishes the general requirements for manual fire alarm boxes and their installation. Occupancy chapters may permit omission of manual boxes in fully sprinklered buildings with automatic detection—verify the applicable provisions for your occupancy.

B. Standpipe Hose Connections

Where a standpipe system is required, standpipe hose connections must be provided on each side of the wall adjacent to the exit openings of horizontal exits (NFPA 14). NFPA 14 §7.3.2.2.1 permits omission of hose connections adjacent to horizontal exits where all floor areas are reachable within 200 feet for sprinklered buildings (or 130 feet for nonsprinklered buildings) from a hose connection located in a stairwell.

Key point: The horizontal exit is not just a door—it is an interface point for fire alarm and standpipe systems.

Pro Tip: Coordinate fire protection and fire alarm system designs with horizontal exits depicted on life safety plans.

◆ Section 9: Design Checklist for Horizontal Exits

◆ Section 10: Common Mistakes and How to Avoid Them

◆ Section 11: Conclusion

Horizontal exits are unique among egress components. They move occupants through a fire-rated separation to a refuge area on the same level, without requiring stairs or exiting the building. They are most valuable in hospitals, large floor plates, and retrofits where additional egress capacity is needed.

But they are also fragile. The fire barrier must be complete and total. The doors must be rated, self-closing, and properly arranged. The refuge area must be large enough. And the capacity limit—50 percent general, two-thirds for health care—must be respected.

Key Takeaways:

1. A horizontal exit is a way of passage through a fire barrier to a refuge area on approximately the same level.

2. The fire barrier must have a minimum 2-hour fire resistance rating.

3. Doors must have a minimum 1½-hour fire protection rating.

4. Doors must swing in the direction of egress travel; opposite swing required where serving both sides.

5. Where exit hardware is required or provided on a rated door, it must be fire exit hardware (UL 305 + UL 10C).

6. Horizontal exits can provide up to 50 percent of total egress capacity (up to two-thirds for health care, with other exits not below one-third).

7. Refuge area must be sized per occupancy requirements (30 sq ft/patient; 15 sq ft/resident; 6 sq ft/occupant) on each side.

8. Door clear width must be at least 32 inches; existing 34-inch doors permitted as exception.

9. Manual fire alarm boxes required within 60 inches of exit doorways (NFPA 101 §9.6.2.3).

10. Standpipe hose connections required on each side where standpipe is required (NFPA 14 §7.3.2.2.1).

Take Action Today:

1. Verify the fire barrier serving as a horizontal exit has a 2-hour rating.

2. Confirm doors are 1½-hour rated and swing in the direction of egress travel.

3. Verify refuge area size meets occupancy requirements on each side.

4. Confirm horizontal exits provide no more than 50 percent (general) of total egress capacity; health care may allow up to two-thirds with other exits not below one-third.

5. Verify manual fire alarm boxes are within 60 inches of exit doorways.

6. Confirm standpipe hose connections on each side, or verify omission criteria.

7. Verify that where exit hardware is required or provided on rated doors, it is fire exit hardware (UL 305 + UL 10C).

8. Coordinate fire alarm and standpipe designs with horizontal exits on life safety plans.

IBC Note

The International Building Code 1026.1 establishes its own horizontal exit capacity limit: 50 percent of the required exit capacity, with exceptions for certain occupancies. Where the IBC is the governing code, verify the IBC horizontal exit capacity requirements against your adopted edition—they may differ from NFPA 101.

Continue Reading from Our Series:

• Related guide: How to Know How Many Exits Are Required (NFPA 101 Table 7.4)

• Learn more: Subdivision of Building Spaces and Smoke Compartments (NFPA 101)

• Read more: Fire Safety for Places of Worship

IMPORTANT DISCLAIMER: This guide references the International Fire Code (IFC) Section 510, Emergency Responder Communication Coverage; the International Building Code (IBC) Section 916; NFPA 1225, Standard for Emergency Services Communications (2022 edition, which consolidated NFPA 1221 and NFPA 1061); and NFPA 72, National Fire Alarm and Signaling Code (2022 edition for pathway survivability). These codes vary significantly by edition and are frequently amended by state and local jurisdictions. The 2024 IFC is the most recent published edition, but many jurisdictions still enforce earlier editions. The section references in this article (IFC 510.4.1.1, 510.5.3, 510.6.1.1) are drawn from the 2018 and 2021 editions — verify against the edition your AHJ has adopted, as numbering can shift. NFPA 1225 (2022) is the current consolidated standard, with a 2027 edition in development. Critical area designations and coverage percentage requirements are frequently modified by local AHJ amendments. Local amendments and the edition adopted by your Authority Having Jurisdiction (AHJ) always control. This guide is a starting point only. Always verify the specific requirements applicable to your project with your local AHJ.

Emergency Responder Radio Coverage Systems (ERRCS)—also called Emergency Responder Communication Enhancement Systems (ERCES)—ensure that first responders can communicate inside buildings where radio signals from the outside cannot penetrate. Modern construction materials—concrete, steel, low-E glass—block or weaken radio signals. Without enhancement, firefighters inside a stairwell or basement may not be able to talk to the incident commander outside.

The requirement is straightforward: buildings must provide reliable radio coverage for emergency responders. How you achieve that coverage—with a bi-directional amplifier (BDA) and distributed antenna system (DAS), or without enhancement if natural coverage is adequate—is determined by testing.

This article covers the regulatory framework, signal strength requirements, system design, and testing protocols for ERRCS under IFC 510 and NFPA 1225.

◆ Section 1: Why ERRCS Is Different

ERRCS is not a fire alarm system, not a suppression system, and not a notification system. It is a radio coverage system, and that distinction matters.

Key point: ERRCS is driven by the building and fire codes, not by NFPA 72 alone. The IFC and IBC establish when ERRCS is required and what coverage is acceptable. NFPA 1225 establishes how the system is designed, installed, and tested. NFPA 72 defines pathway survivability levels that NFPA 1225 references.

Pro Tip: The AHJ determines which agencies must be supported and what frequencies must be covered. Do not assume that covering fire department frequencies alone is sufficient—police and EMS may also need coverage.

◆ Section 2: Regulatory Framework

ERRCS is governed by a layered set of codes and standards.

Key point: NFPA 1225 (2022) consolidated NFPA 1221 and NFPA 1061 into a single standard. Chapter 18 addresses in-building ERCES requirements. Pathway survivability levels are defined in NFPA 72 Chapter 12 and referenced by NFPA 1225.

Key Article: Article 118 — Fire Alarm System Zoning and Addressable Design (NFPA 72)

Pro Tip: The IFC and IBC establish the requirement; NFPA 1225 and NFPA 72 establish the design and testing methodology. Both must be satisfied.

◆ Section 3: When ERRCS Is Required

A. The Baseline Requirement

Under IFC 510.1, new buildings must have approved radio coverage for emergency responders, unless an exception applies. The baseline is that coverage is required; the question is whether natural coverage is adequate or enhancement is needed.

B. Common Triggers for Testing

The specific triggers for when a signal strength test is required vary by jurisdiction. Common factors that lead an AHJ to require testing include:

Key point: The IFC 510.1 baseline is that coverage is required; the specific thresholds and triggers are set by the AHJ. Verify the applicable triggers with your jurisdiction before design.

C. The RF Survey

Before ERRCS can be designed, an initial RF survey must be conducted to determine whether natural coverage is adequate. The survey identifies:

• Current signal strength levels (inbound and outbound)

• Dead zones requiring enhancement

• The frequencies used by local emergency responders

If the survey demonstrates that natural coverage meets the required thresholds, no ERRCS is required. If coverage is inadequate, an enhancement system must be designed and installed.

Key point: ERRCS is installed only where needed. The RF survey is the mechanism for determining need.

Pro Tip: The RF survey must be conducted when the building is substantially complete—after interior walls, doors, and finished materials are installed—to ensure accurate results.

◆ Section 4: Signal Strength and Coverage Requirements

IFC 510 establishes the minimum signal strength and coverage percentages.

A. Signal Strength Requirements (IFC 510.4.1)

Key point: The −95 dBm inbound minimum is the stated code figure in the 2018 and 2021 IFC. The outbound (uplink) requirement is expressed as DAQ 3.0. A system can meet the inbound threshold but fail outbound due to donor site ERP differences—verify both.

B. Coverage Percentages and Test Pass Criteria

Important distinction: The design requirement in IFC 510.4.1 is 95% general and 99% critical coverage. The acceptance procedure in IFC 510.5.3 uses a 90% test with a two-area allowance. The annual test in IFC 510.6.1.1 requires 95% general and 99% critical coverage.

This mismatch exists in the IFC text and is a known source of confusion. Confirm how your AHJ applies it before finalizing design or testing.

Note on critical areas: The 99% requirement is for coverage. The verification method for critical areas is set by the AHJ.

C. Critical Area Designations

Critical areas are designated by the fire code official. Commonly designated critical areas include:

• Fire command centers

• Fire pump rooms

• Interior exit stairways

• Exit passageways

• Elevator lobbies

• Standpipe cabinets

• Sprinkler sectional valve locations

• Other areas designated by the AHJ

Key point: The critical area list is illustrative and AHJ-controlled. Even the 2018 IFC enumeration ended with “other areas deemed critical by the fire code official.” Verify the critical area designations with your AHJ before design.

Pro Tip: A system designed to a generic list may fail inspection if the AHJ has designated additional critical areas.

◆ Section 5: System Design — BDA and DAS

ERRCS is typically implemented with a Bi-Directional Amplifier (BDA) and a Distributed Antenna System (DAS).

A. System Components

B. UL 2524 Listing

Signal boosters must be UL 2524 listed. UL 2524 is the product performance standard for in-building 2-way emergency radio communication enhancement systems.

Key point: UL 2524 listing is required for AHJ acceptance. Unlisted equipment will not be approved.

C. Pathway Survivability (NFPA 72 Chapter 12)

Pathway survivability ensures the system survives fire conditions. These levels are defined in NFPA 72 12.4 :

Key point: The required level is based on building type, occupancy, fire risk assessment, and AHJ determination. High-rise buildings typically require Level 2 or 3.

D. Backup Power

The standby power supply must operate the ERCES at 100% system operation for not less than 12 hours. Some jurisdictions require longer durations—check with your AHJ.

E. Monitoring and Annunciation

A dedicated annunciator panel must be located in the fire command center or other AHJ-designated location. The BDA and DAS status must be monitored by the building fire alarm system through NFPA 72 supervisory signal provisions.

Key point: The ERRCS is not a standalone system. It must interface with the fire alarm system for monitoring and annunciation.

F. Coordination with the Radio System Owner

FCC regulation 47 CFR 90.219 requires that non-licensees seeking to operate signal boosters must obtain the express consent of the licensee(s) of the frequencies for which the device or system is intended to amplify. The consent must be maintained in a recordable format that can be presented to an FCC representative.

Key point: A written Letter of Consent from the radio system owner/licensee is typically required before connecting a BDA. This is a common real-world holdup on ERRCS projects.

G. Donor Antenna Details

Pro Tip: Donor antenna isolation testing is part of the annual operational test. Verify isolation values are maintained to prevent oscillation.

◆ Section 6: Acceptance Testing and Commissioning

Acceptance testing verifies that the installed system meets coverage requirements.

A. Grid-Based Testing (IFC 510.5.3)

The floor is divided into approximately 20 equal test areas per floor. A test location approximately in the center of each area is selected, and the radio is enabled to verify two-way communications.

Acceptance test procedure:

If the system fails the 40-area test, it must be altered to meet the 90 percent coverage requirement.

Annual test threshold (IFC 510.6.1.1):

• General areas: 95% on each floor

• Critical areas: 99%

Key point: The acceptance procedure (90% with two-area allowance) is more permissive than the annual test threshold (95%). This mismatch exists in the IFC text and is a known source of confusion. Confirm with your AHJ how the acceptance test result is reconciled with the design requirement of 95%.

B. Signal Strength Measurements

Signal strength measurements are taken at the center of each grid cell using standardized parameters. The test uses a calibrated portable radio of the latest brand and model used by the agency.

C. DAQ Testing

Delivered Audio Quality (DAQ) is a subjective measure of voice intelligibility. The TSB-88 DAQ scale runs 1, 2, 3, 3.4, 4, 4.5, 5 :

DAQ 3.0 is the minimum per IFC 510.4.1. Some jurisdictions require DAQ 3.4 or higher.

D. Spurious Oscillation Testing

A spectrum analyzer or other suitable test equipment must be used to ensure spurious oscillations are not being generated by the signal booster. This test is conducted at installation and at subsequent annual inspections.

Key Point: The acceptance test is not complete until signal strength, DAQ, and spurious oscillation testing have all passed.

◆ Section 7: Periodic Inspection, Testing, and Maintenance

NFPA 1225 Chapter 20 establishes ongoing ITM requirements.

A. Visual Inspection

Inspection items:

• Normal AC power

• Loss of normal AC power

• Battery charger failure

• Low battery capacity

• Donor antenna signal source malfunction

• Active RF-emitting device malfunction

• Active system component malfunction

• Loss of communication with fire alarm control panel

• Signs of physical damage

B. Annual Operational Testing

All systems must be operationally tested at least annually. Annual tests include:

1. At least one quantitative DAQ test on each floor

2. Signal booster gain verification — gain must be the same as during initial installation

3. Backup battery load test — 1-hour load test

4. Active component verification — operation within manufacturer’s specifications

5. Supervisory signal testing — all required monitoring signals

6. Spurious oscillation testing — spectrum analyzer

7. Donor antenna isolation verification — 20.3.10.2.3.2(7)

8. Building structure change evaluation — assess if changes impact coverage

Key Point: Annual testing is required by IFC 510 and NFPA 1225. Records must be maintained and available for AHJ inspection.

Pro Tip: When original acceptance test documentation is lost, the building owner may be required to rerun the acceptance test to reestablish baseline gain values.

◆ Section 8: Design Checklist for ERRCS

◆ Section 9: Common Mistakes and How to Avoid Them

◆ Section 10: Conclusion

Emergency Responder Radio Coverage Systems ensure that first responders can communicate inside buildings where radio signals cannot penetrate. They are required by the IFC and IBC, designed and tested under NFPA 1225, and use pathway survivability levels defined in NFPA 72.

Key Takeaways:

1. ERRCS is required when buildings cannot achieve adequate radio coverage for emergency responders.

2. An RF survey determines need — ERRCS is installed only where natural coverage is inadequate.

3. IFC 510 establishes signal requirements: −95 dBm minimum inbound; DAQ 3.0 minimum outbound; 95% general coverage; 99% critical coverage.

4. The acceptance procedure uses a 90% test with a two-area allowance on the 20-area grid; the annual test threshold is 95% general and 99% critical. This mismatch is a known source of confusion—confirm with your AHJ.

5. Critical areas are designated by the AHJ; the common list is illustrative, not fixed. Verification method for critical areas is set by the AHJ.

6. UL 2524 listing is required for signal boosters.

7. Pathway survivability levels are defined in NFPA 72 12.4 and referenced by NFPA 1225.

8. 12-hour backup power is the minimum; verify AHJ amendments.

9. Dedicated annunciator in fire command center; monitored by fire alarm system per NFPA 72 supervisory signal provisions.

10. Acceptance testing uses grid-based methodology (90% acceptance; two-area allowance), DAQ testing, and spurious oscillation testing.

11. Annual operational testing is required per NFPA 1225 Chapter 20 (95% general; 99% critical).

12. FCC consent from the licensee is required before connecting a BDA.

Take Action Today:

1. Confirm ERRCS applicability for your building with your AHJ.

2. Conduct an initial RF survey after substantial completion.

3. Confirm the frequencies and agencies to be supported.

4. Verify critical area designations with your AHJ.

5. Specify UL 2524 listed BDA equipment.

6. Determine pathway survivability level per NFPA 72 12.4.

7. Verify backup power duration meets AHJ requirements.

8. Provide dedicated annunciator and fire alarm monitoring interface.

9. Obtain Letter of Consent from the radio system licensee.

10. Confirm with your AHJ how the acceptance test result is reconciled with the design requirement.

11. Plan acceptance testing with grid-based (90% acceptance; two-area allowance), DAQ, and spurious oscillation protocols.

12. Schedule annual ITM per NFPA 1225 Chapter 20.

Continue Reading from Our Series:

• Related guide: Voice Evacuation and Mass Notification Systems

• Learn more: Fire Alarm System Zoning and Addressable Design (NFPA 72)

• Read more: What Are the Requirements for Fire Engine Access and Hardstanding

IMPORTANT DISCLAIMER: This guide references NFPA 415, Standard on Airport Terminal Buildings, Fueling Ramp Drainage, and Loading Walkways; NFPA 101, Life Safety Code; NFPA 1, Fire Code; NFPA 30, Flammable and Combustible Liquids Code; NFPA 409, Standard on Aircraft Hangars; NFPA 13, Standard for the Installation of Sprinkler Systems; NFPA 220, Standard on Types of Building Construction; and the International Building Code (IBC). These codes vary significantly by edition and are frequently amended by state and local jurisdictions. NFPA 415 editions include 2022 and 2026. NFPA 409 editions include 2022 and 2026. NFPA 101 editions include 2018, 2021, and 2024. The most recent published editions are NFPA 415 (2026), NFPA 409 (2026), and NFPA 101 (2024), but AHJ-adopted editions commonly lag behind by one or more cycles. The 2026 edition of NFPA 409 raised the Group II aircraft access door height threshold from 28 ft to 35 ft; the effect on Group I and Group III thresholds should be verified against the 2026 text. Local amendments and the edition adopted by your Authority Having Jurisdiction (AHJ) always control. This guide is a starting point only—always verify the specific requirements applicable to your project with your local AHJ.

Airports are among the most complex occupancies in fire safety. A single terminal building can contain assembly occupancies (waiting areas, concourses, food courts), mercantile occupancies (retail shops), business occupancies (offices, airline operations), storage occupancies (baggage handling, cargo), and industrial functions (maintenance, fueling)—all under one roof, all connected by shared egress paths.

That complexity is compounded by the people. Airport terminals serve a population that is constantly changing, frequently unfamiliar with the building, and often encumbered with luggage. A passenger who has never been in the terminal before, carrying two suitcases, and trying to find a gate is not the same as an office worker walking to a familiar stairwell.

This guide covers the fire safety challenges of airports and transportation hubs, with a focus on terminal buildings, aircraft fueling operations, hangars, and the unique egress problems these facilities present.

◆ Section 1: Why Airports Are Different

Airports present fire safety challenges that differ from any single occupancy type.

Key point: The fire safety challenge at an airport is not any single hazard—it is the interaction between them. A fire in a retail shop on the concourse affects the egress path for passengers in the hold room. A fuel spill on the apron affects the boarding bridge that serves as both an egress route and a fire spread path.

Pro Tip: Do not design an airport terminal as a collection of separate occupancies. Design it as a single interconnected system where every space affects every other space.

◆ Section 2: Occupancy Classification Challenges

Airport terminals do not fit neatly into a single occupancy classification. Different areas within the same building may require different classifications.

A. Common Classifications

B. The Classification Decision

NFPA 415, Standard on Airport Terminal Buildings, Fueling Ramp Drainage, and Loading Walkways, provides specific requirements for terminal buildings. The standard addresses:

• Construction and protection of all types of airport terminal buildings

• Design and maintenance of aircraft fueling ramp drainage to reduce the chance of fuel spillage and resulting dangers

• Design, construction, and fire protection of loading walkways connecting the terminal and aircraft

Key point: The presence of NFPA 415 does not override NFPA 101. NFPA 415 supplements NFPA 101 for terminal-specific conditions. Both apply.

Key Article: Article 101 — Fire Safety for Mixed-Occupancy Buildings

Pro Tip: For mixed-occupancy terminals, use the most restrictive requirements for shared egress paths. A corridor serving both a concourse (assembly) and retail area (mercantile) must be designed to the assembly requirements if those are stricter.

◆ Section 3: NFPA 415 and the Regulatory Framework

NFPA 415 is the primary standard for airport terminal buildings. Its requirements complement NFPA 101 and the IBC.

A. Scope of NFPA 415

NFPA 415 covers:

• Airport terminal buildings

• Fueling ramp drainage

• Loading walkways (boarding bridges)

B. Key Requirements

Key point: The loading walkway (boarding bridge) is not just a convenience—it is a regulated egress component and a potential fire spread path. NFPA 415 requires the aircraft loading walkway to have a pressurization system for safe egress.

Pro Tip: The apron surface must be sloped away from the building in case of a fuel spill, and the building must be of Type I, Type II, or Type IV construction. Verify these requirements against your adopted edition.

◆ Section 4: Terminal Egress and Occupant Load

Egress in airport terminals is complicated by high occupant loads, transient populations, and security constraints.

A. Occupant Load Factors

Occupant load in terminal areas depends on the specific use:

Key Article: Article 34 — How to Determine Occupant Load (NFPA 101 Table 7.3.1.2)

B. Egress Challenges

C. Exit Marking and Wayfinding

Exit signs in airports must be visible and understandable to a multilingual, transient population. NFPA 101 requires exit signs that are visible and illuminated; airports often supplement with additional wayfinding.

NFPA 415 requirement: In addition to the exit signage requirements specified in NFPA 101, doors serving as exits that discharge onto an airport ramp and are provided solely for the purpose of meeting emergency egress requirements from public areas shall be placarded “Emergency Exit Only” in letters at least 2 in. (50 mm) high.

Pro Tip: In terminal design, egress must be designed for the occupant who has never been there before. If a first-time passenger cannot find the exit in an emergency, the design has failed—regardless of code compliance.

◆ Section 5: Concourse and Boarding Bridge Hazards

The concourse and boarding bridge are unique to airports and present hazards not found in other occupancies.

A. Concourse Hazards

B. Boarding Bridge (Loading Walkway) Requirements

NFPA 415 addresses loading walkways specifically. Key requirements include:

• Construction: Noncombustible materials

• Egress: Walkway serves as an egress route; must be maintained clear

• Fire protection: Protection for the walkway and its connection to the terminal

• Separation: Protection from aircraft fuel fires on the apron

• Pressurization: The aircraft loading walkway has a pressurization system for safe egress

Key point: The boarding bridge is a dual-purpose component—it is both a normal passenger path and an emergency egress route. It must be protected accordingly.

Pro Tip: During a fire, the boarding bridge may be the fastest way off the aircraft—but it may also be the path the fire uses to enter the terminal. Verify the bridge’s fire separation from the terminal and its protection from apron fires.

◆ Section 6: Aircraft Fueling and Fuel Storage

Aircraft fuel is one of the most significant hazards at an airport. Jet fuel is a Class II combustible liquid with a flash point above 100°F (38°C).

A. Jet Fuel Characteristics

B. Fueling Operations

Aircraft fueling operations are governed by NFPA 407, Standard for Aircraft Fuel Servicing. Key safety requirements include:

• Bonding and grounding to prevent static ignition

• Fueling personnel training

• Emergency shutdown procedures

• Spill containment on the apron

C. Fueling Ramp Drainage

NFPA 415 requires fueling ramp drainage systems to prevent fuel from flowing into terminal buildings or other occupied spaces. The drainage system must:

• Collect fuel spills on the apron

• Prevent fuel from entering the terminal

• Route spills to a safe location

Key Article: Article 46 — Hazard Classification (Low, Ordinary, High) and Hazardous Areas (NFPA 101)

Pro Tip: The most dangerous fire scenario at an airport is a fuel spill fire on the apron while passengers are boarding or deplaning. The fueling ramp drainage system, the boarding bridge protection, and the emergency response plan all work together to address this scenario.

◆ Section 7: Hangars and Maintenance Facilities

Aircraft hangars present unique fire protection challenges governed by NFPA 409, Standard on Aircraft Hangars.

A. Hangar Classification (Corrected)

NFPA 409 classifies hangars into four groups based on door height, single fire area, and construction type. The classification is not based on a single criterion—it depends on the specific combination of these factors.

Critical 2026 change: The 2026 edition raised the Group II aircraft access door height threshold from 28 ft to 35 ft. The effect on Group I and Group III thresholds should be verified against the 2026 text before relying on them.

Key point on Group III: The threshold is 12,000 ft², not 3,000 ft². The “single aircraft” description refers to a type of Group III hangar (freestanding unit), not the defining criterion.

B. Key Hazards

C. Fire Suppression Options

Fire suppression system options vary by group and fuel state:

• Group I and II (fueled aircraft): Foam-water deluge system, or sprinkler system combined with low-level foam

• Group III (fueled aircraft): Suppression system required only if hazardous operations occur; if so, Group II requirements apply. Hazardous operations include fuel transfer, welding, torch cutting, torch soldering, doping, and spray painting

• Group IV: Suppression system requirements depend on several factors under NFPA 409 §9.14; verify the exact threshold against your adopted edition

Pro Tip: Aircraft hangars are not warehouses. The aircraft itself is a large, irregular obstruction that affects sprinkler coverage. NFPA 409 addresses these challenges specifically—do not design a hangar using NFPA 13’s general storage provisions.

◆ Section 8: Fire Alarm and Detection

Airport fire alarm systems must address the unique conditions of terminal and airside operations.

A. Alarm Notification

Airport alarm systems must notify:

• Terminal occupants (passengers and staff)

• Airline operations

• Airport fire service

• Airport operations center

Key point: The alarm system is not just for occupant notification—it is an operational system that coordinates response across multiple agencies.

Key Article: Article 21 — Fire Alarm System Requirements for Commercial Buildings

◆ Section 9: Suppression Systems

Suppression requirements vary significantly by area.

A. Terminal Sprinkler Requirement

NFPA 415 (as extracted in NFPA 1) requires: an airport terminal building with more than 12,000 ft² (1,115 m²) total floor area for the assembly portion of the occupancy shall be provided with an automatic sprinkler system.

B. Foam Systems

Aircraft fuel fires require foam—water alone can spread a fuel fire by floating burning fuel on the water surface. Foam systems for hangars and fuel storage are governed by NFPA 11, Standard for Low-, Medium-, and High-Expansion Foam.

Pro Tip: The most common design mistake in hangars is underestimating the foam requirement. Aircraft fuel fires are challenging, and foam systems must be designed, installed, and maintained by qualified professionals.

◆ Section 10: Design Checklist for Airports and Transportation Hubs

◆ Section 11: Common Mistakes and How to Avoid Them

◆ Section 12: Conclusion

Airports are among the most complex fire safety challenges in commercial construction. They combine multiple occupancies, transient populations, luggage-encumbered egress, aircraft fuel hazards, and 24/7 operations—all in a single interconnected facility.

Key Takeaways:

1. Airports are mixed-occupancy buildings—assembly, mercantile, business, storage, and industrial functions coexist under one roof.

2. NFPA 415 provides terminal-specific requirements that supplement NFPA 101 and the IBC.

3. Egress must be designed for transient occupants—first-time passengers with luggage, not familiar office workers.

4. Boarding bridges are dual-purpose—they are both egress paths and potential fire spread paths, with pressurization systems for safe egress.

5. Fueling ramp drainage must prevent fuel from entering terminal buildings.

6. Hangars are governed by NFPA 409, with group classification based on door height, single fire area, and construction type—not a single criterion.

7. Foam is required for fuel fires—water alone can spread a fuel fire.

8. Pre-incident planning is essential—the airport fire service and ARFF must know the facility before an emergency.

9. The 2026 NFPA 409 edition raised the Group II door height threshold from 28 ft to 35 ft; the effect on Group I and III should be verified against the 2026 text.

10. Airport terminal buildings must be Type I, Type II, or Type IV construction per NFPA 220.

Take Action Today:

1. Verify occupancy classification for each area of your terminal.

2. Confirm NFPA 415 compliance for construction, separation, and loading walkways.

3. Review egress design from the perspective of a first-time passenger with luggage.

4. Verify boarding bridge fire protection, separation from the terminal, and pressurization.

5. Confirm fueling ramp drainage prevents fuel entry to terminal buildings.

6. For hangars, verify NFPA 409 group classification based on door height, fire area, and construction type.

7. Coordinate with your airport fire service for pre-incident planning.

8. Train airport staff, tenant staff, and airline personnel on emergency procedures.

Continue Reading from Our Series:

• Related guide: Fire Safety for Mixed-Occupancy Buildings (Article 101)

• Learn more: How to Design Fire Safety for Assembly Occupancies (Article 94)

• Read more: How to Determine Occupant Load (NFPA 101 Table 7.3.1.2) (Article 34)

IMPORTANT DISCLAIMER: This guide references NFPA 101, Chapter 43 (Building Rehabilitation) and NFPA 914, Code for the Protection of Historic Structures, where applicable to existing building retrofits. NFPA 101 and NFPA 914 requirements vary significantly by edition and are frequently amended by state and local jurisdictions. NFPA 101 editions include 2018, 2021, and 2024. NFPA 914 editions include 2019 and 2023. The most recent published editions are NFPA 101 (2024) and NFPA 914 (2023), but AHJ-adopted editions commonly lag behind by one or more cycles. Local amendments and the edition adopted by your Authority Having Jurisdiction (AHJ) always control. This guide is a starting point only—always verify the specific requirements applicable to your project with your local AHJ.

Mixed-occupancy buildings are the norm in modern commercial real estate. Ground-floor retail, second-floor offices, residential above, a restaurant tucked into a corner, a gym in the basement — each occupancy brings its own fire safety requirements. When they stack, those requirements can conflict.

A residential occupancy demands separation and low-frequency alarms. A mercantile occupancy demands egress capacity and suppression. An assembly occupancy demands voice notification and higher sprinkler densities. A business occupancy demands flexibility and often fewer prescriptive features. Put them in the same building, and the designer faces a set of decisions that cannot be resolved by opening a single code chapter.

This guide walks through how to identify, evaluate, and resolve those conflicts using NFPA 101, with practical AHJ coordination strategies. It builds on the occupancy separation principles covered in Article 45 and the compartmentation framework in Article 44.

◆ Section 1: What Counts as a Mixed-Occupancy Building

A mixed-occupancy building contains two or more occupancy classifications under NFPA 101. The most common combinations in commercial real estate are:

Key point: The building is classified by its most restrictive occupancy for many code applications — but not always. NFPA 101 allows separated occupancies to be treated independently if specific criteria are met.

Pro Tip: Determine early whether your project will pursue separated occupancies or mixed occupancies. This single decision affects every subsequent design choice — from egress width to sprinkler density to alarm zoning.

◆ Section 2: The Regulatory Framework

Mixed-occupancy design is governed by NFPA 101 Chapters 6 (Classification of Occupancy and Hazard of Contents) and 7 (Means of Egress), with occupancy-specific requirements in Chapters 12 through 43.

Terminology note: NFPA 101 uses the term “mixed occupancies” for what the IBC calls “non-separated occupancies.” The concepts are similar, but NFPA 101 6.1.14.1.2 adds a mandatory trigger: shared exit access forces mixed-occupancy treatment even if the design otherwise resembles separated occupancies. This is a trigger, not a gateway — a designer can still elect mixed treatment for buildings with no shared egress.

Key Article: Article 33 — NFPA 101 Chapter Organization and Occupancy Key

Pro Tip: Mixed-occupancy buildings often trigger change of occupancy provisions when one occupancy is added or expanded. This is where NFPA 101 Chapter 43 comes into play — and where early AHJ engagement is essential.

◆ Section 3: The Core Conflict — Separated vs. Mixed Occupancies

NFPA 101 6.1.14 provides two paths for buildings with multiple occupancies. The choice between them is the single most consequential decision in the design process.

A. Separated Occupancies

Under the separated approach, each occupancy is treated independently. Fire-rated barriers — fire walls, fire barriers, or fire partitions — separate the occupancies. Each occupancy must comply with its own requirements for egress, suppression, and detection, and the separation must meet the rating required by Table 6.1.14.4.1.

Advantage: Design flexibility. Each occupancy can be optimized to its own requirements.

Disadvantage: Fire-rated barriers are expensive, occupy floor area, and constrain architecture.

B. Mixed Occupancies

Under the mixed approach, the most restrictive requirements apply throughout the building. This means:

• The strictest egress requirements apply to all egress paths
• The strictest suppression requirements apply to the entire building
• The strictest detection and alarm requirements apply throughout

Critical trigger: NFPA 101 6.1.14.1.2 states that where exit access from one occupancy traverses another, the building must be treated as a mixed occupancy. This is a mandatory trigger, not a prohibition on choosing mixed occupancy elsewhere — a designer can still elect mixed treatment for buildings with no shared egress.

Advantage: No rated barriers required within the building footprint.

Disadvantage: Over-design. A residential requirement applied to a retail space may be more than the retail needs — but it applies nonetheless.

C. The Trade-Off in Practice

Pro Tip: For buildings with three or more distinct occupancies, the separated approach is usually more cost-effective. For buildings with two similar occupancies (e.g., mercantile + business), the mixed approach may be simpler. Run a cost-benefit analysis before locking the approach. See Article 54 — The Cost-Benefit Analysis of Fire Protection Systems.

◆ Section 4: Occupancy Separation Requirements

NFPA 101 Table 6.1.14.4.1 establishes the required separation ratings between occupancies in the separated approach. The table is published in two parts and includes a sprinkler reduction mechanism with specific limits.

A. How to Read Table 6.1.14.4.1

The table is published in two parts:

Note: The Part 1 / Part 2 occupancy split is based on the 2024 edition. The structure has changed between editions — always verify against your AHJ-adopted edition.

To determine the required separation for your occupancy pair:

1. Locate the row and column for the two occupancies in the applicable table.
2. Note the base rating (e.g., 2 hours).
3. If the building is fully sprinklered and supervised, reduce the rating by 1 hour — but never below 1 hour.
4. Check for a dagger (†) in the cell. If present, the sprinkler reduction is not permitted.

B. The Sprinkler Reduction — Capped and Conditional

NFPA 101 Table 6.1.14.4.1 permits a 1-hour reduction in required separation ratings where the building is protected throughout by an approved, supervised automatic sprinkler system. However, two limits apply:

Sprinklers do not eliminate rated separations. They reduce them by one hour, subject to these limits.

C. Worked Example

Assembly >300 to ≤1000 vs. Day-Care >12 Clients. The base rating is 2 hours. In a sprinklered building, this reduces to 1 hour (2 − 1 = 1, which meets the floor of 1 hour).

Note: This example is verified against the 2024 edition. Verify against your AHJ-adopted edition before relying on it.

D. Important Notes

Pro Tip: Always pull the actual Table 6.1.14.4.1(a) and (b) from your adopted edition. The ratings vary between editions, and cells that were empty in one edition may have values in another. Do not rely on summaries or third-party tables.

Key Articles: Article 45 — Occupancy Separation Requirements; Article 44 — Subdivision of Building Spaces and Smoke Compartments

◆ Section 5: Egress Conflicts

Egress is where mixed-occupancy conflicts bite hardest.

A. Shared Egress Paths

When two occupancies share an egress path — corridor, stair, or exit discharge — the shared path must be designed to the most restrictive occupancy requirement.

Example: A corridor serving both a business occupancy and a residential occupancy must be designed to the residential egress requirements, which are typically stricter.

B. Occupant Load Calculations

Occupant load is calculated separately for each occupancy using the factors in NFPA 101 Table 7.3.1.2. The factors are chosen based on use of the space, not just occupancy classification. For shared egress, the loads are summed.

Important: The occupant load factor is based on how the space is used, not the occupancy classification. A bar area in an assembly occupancy uses the standing space factor; the adjacent dining area with tables and chairs uses the less concentrated factor.

Key Articles: Article 34 — How to Determine Occupant Load; Article 35 — How to Know How Many Exits Are Required; Article 37 — Travel Distance Limits by Occupancy Type

Pro Tip: Document egress calculations per occupancy and per shared path. AHJs frequently request this during plan review, and clear documentation prevents costly revisions.

◆ Section 6: Suppression Conflicts

Fire suppression requirements vary significantly by occupancy.

A. NFPA 13 vs. 13R vs. 13D

The 13R scope has two conditions: NFPA 13R is permitted for residential occupancies four stories or fewer in buildings not exceeding 60 feet in height above grade plane. A 4-story building exceeding 60 feet above grade plane does not qualify.

2021 IBC tightening: The 2021 IBC added a requirement that the floor level of the highest story be 30 feet or less above the lowest level of fire department vehicle access. This effectively limits many 13R buildings to 3 stories in practice, because typical floor-to-floor heights push the 4th story above 30 feet. The 2024 IBC increased this to 45 feet for Group R-2 occupancies.

B. NFPA 13R in Mixed-Occupancy Buildings

The guidance for NFPA 13R in mixed-occupancy buildings is clear:

The reason: NFPA 13R is designed for residential hazards only. It is not intended for the higher hazard levels associated with commercial, mercantile, or assembly occupancies. When occupancies are not separated, the residential system cannot provide adequate protection for the entire building.

Pro Tip: The 2024 edition of NFPA 101 added automatic sprinkler requirements for new parking structures. For mixed-use buildings with attached parking, verify whether these apply to your design.

◆ Section 7: Fire Alarm and Notification Conflicts

Fire alarm and notification requirements vary by occupancy. The conflicts are real and require careful design.

A. Addressable Systems as a Solution

An addressable fire alarm system with occupancy-specific zoning is often the cleanest solution for mixed-occupancy buildings. It allows one panel to serve multiple occupancy requirements without redundant equipment.

Benefits:

• Occupancy-specific notification (low-frequency for residential, voice for assembly)
• Per-occupancy alarm silence protocols
• Granular system diagnostics
• Scalable for future modifications

Key Articles: Article 21 — Fire Alarm System Requirements; Article 42 — Fire Alarm System Requirements by Occupancy; Article 22 — When Is a Fire Alarm System Required

Pro Tip: For mixed-use buildings with residential occupancies, NFPA 72 requires low-frequency notification in sleeping areas — typically 520 Hz. Verify whether your design meets this requirement, as it is commonly missed.

◆ Section 8: AHJ Coordination

No mixed-occupancy project succeeds without early AHJ engagement.

A. What to Bring to Pre-Application

• Preliminary occupancy classification per floor
• Proposed approach (separated or mixed)
• Schematic egress strategy
• Proposed suppression and alarm approach
• Any alternative compliance requests
• Existing building documentation (if retrofit)

B. Documenting Interpretations

Get written confirmation of any alternative approaches. Verbal approvals disappear when inspectors change. A simple letter or email summary of the AHJ’s acceptance is sufficient documentation.

Key Articles: Article 50 — What to Do During a Fire Department Inspection; Article 56 — The Architects Checklist for Building Code Compliance

Pro Tip: If your AHJ is unfamiliar with a specific mixed-occupancy configuration, offer to walk through your code analysis during the pre-application meeting. Many AHJs appreciate the opportunity to review the logic before formal submittal.

◆ Section 9: Documentation and Compliance Checklist

Key Article: Article 71 — How to Write Effective Fire Safety Reports and Documentation

◆ Section 10: Common Mistakes and How to Avoid Them

◆ Section 11: Conclusion

Mixed-occupancy fire safety is not about finding the single “right” answer — it’s about reconciling competing requirements in a way the AHJ accepts and the building sustains.

Key Takeaways:

1. Classify each occupancy accurately — everything flows from this.
2. Choose separated or mixed approach early, with a cost-benefit analysis.
3. Remember that NFPA 101 6.1.14.1.2 can mandate mixed occupancies when egress traverses — but it is a trigger, not a gateway.
4. Calculate egress, suppression, and alarm requirements per occupancy.
5. Apply the strictest requirement to shared systems and paths.
6. Engage the AHJ before design is locked.
7. Document everything — especially alternative approaches.

Take Action Today:

1. Confirm occupancy classifications for every floor.
2. Decide separated vs. mixed, and document the rationale.
3. Verify whether shared egress triggers mandatory mixed occupancy.
4. Calculate occupant loads per occupancy and for shared egress.
5. Confirm sprinkler design basis — NFPA 13, 13R, or 13D.
6. Verify alarm notification requirements per occupancy.
7. Schedule a pre-application meeting with your AHJ.

Continue Reading from Our Series:

• Master reference: The Complete Guide to Commercial Building Fire Safety
• Foundation: Occupancy Separation Requirements (NFPA 101 Table 6.1.14.4.1)
• Related guide: Subdivision of Building Spaces and Smoke Compartments (NFPA 101)
• Read more: How to Determine Occupant Load (NFPA 101 Table 7.3.1.2)