NFPA 285 is the “Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Wall Assemblies Containing Combustible Components.” How’s that for a title? Despite the lengthy name, the goal of the test is quite simple – to understand how fire will spread on an exterior wall. In this article, we’ll briefly review the history of NFPA 285, discuss the criteria for the rest, and then review when compliance with NFPA 285 is required in the IBC. NFPA 285 HistoryThe NFPA 285 standard was first published in 1998 and is currently on it’s 4th edition, published in 2019. But the origins of NFPA 285 go all the way back to the 1970s, when foam plastic insulation became a popular choice for energy conservation in (or on) exterior walls. Based on work by the Society of Plastics Industry, the first test for flammability characteristics of an exterior wall was developed. This test was named UBC 17-6 and was first adopted by the Uniform Building Code (UBC) in 1988. This same test was later renamed as UBC 26-4 [1]. UBC 17-6/UBC 26-4 was a massive, full-scale test, consisting of a two-story exterior wall, totaling 24 feet in height (12 feet for each story). The test evaluated both vertical and lateral flame spread on nonload-bearing exterior walls containing foam plastics. Several wall assemblies containing foam plastics passed the test and, starting with the 1988 UBC, could be used as exterior wall assemblies in Type I, II, III and IV construction. A few years later, a modified test, using a smaller scale was adopted as UBC 26-9. 10 years after the first adoption UBC 26-4, NFPA released the first edition of NFPA 285, entitled “Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Non-Load-Bearing Wall Assemblies Containing Combustible Components.” This version of NFPA 285, published in 1998, is the same as the UBC 26-9 test. Notice the difference in the name between the 1998 version of NFPA 285 and the 2019 version. The “nonload-bearing” restriction has been removed, now allowing load-bearing walls to be tested (although the standard itself does not require the application of a live load during testing). NFPA 285 Test CriteriaThe NFPA 285 testing criteria is nuanced, with variations based on the materials used in the wall assembly and the thickness of certain components in the wall assembly. For a full explanation of the acceptance criteria, review Section 10.2 of the 2019 edition of NFPA 285. Generally, the acceptance criteria involves the following: Flame propagation on the exterior face of the wall assembly
Flame propagation through combustible components and insulation Depending on the materials used in the exterior wall assembly, there are various temperature requirements that must be met. These include:
These temperature requirements apply both vertically and laterally and are measured by thermocouples placed above and to the side of the first story window opening. Temperatures in the second story
Flame Propagation to second story
Flame propagation to adjacent horizontal spaces
When is NFPA 285 Compliance Required?In the 2021 IBC, there are a number of triggers for NFPA 285 compliance. If you are using an earlier version of the code, the requirements are fairly similar, but refer to the corresponding sections in the applicable code edition for the specific details. Water Resistive Barriers (IBC 1402.5) Exterior walls in buildings of Type I, II, III or IV construction that are greater than 40 feet above grade plane must comply with NFPA 285 if they contain a water-resistive barrier. There are two key exceptions:
For this section, fenestration products, flashing of fenestration and water-resistive-barrier flashing are not considered to be part of the weather-resistive-barrier. If any of these materials are combustible, the exceptions above do not apply. Metal Composite Materials (MCMs) (IBC 1406.10.3) Exterior walls containing MCMs in buildings of Type I, II, III or IV construction that are greater than 40 feet above grade plane must comply with NFPA 285. Note that the 2021 IBC has removed several exceptions that existed in previous editions regarding the height of the MCM panels and the area of wall covered by the panels. High-Pressure Laminates (HPLs) (IBC 1408.10.4) Exterior walls containing HPLs in buildings of Type I, II, III or IV construction must comply with NFPA 285. There are two key exception for when HPLs are installed 40 feet or less above grade plane:
Mechanical Equipment Screens (IBC 1511.6.2) Compliance with NFPA 285 is one of three possible code paths for providing combustible mechanical equipment screens on the roof decks of buildings of Type I, II, III or IV construction. Foam Plastic Insulation (IBC 2603.5.5) Exterior walls containing foam plastic insulation in buildings of Type I, II, III or IV construction of any height must comply with NFPA 285. There are several exceptions:
Fireblocking (IBC 718.2.6, Exception 3) Fireblocking is not required in exterior walls when the exterior wall covering complies with NFPA 285. Key Items to KnowWall Assembly vs. Wall Components NFPA 285 tests wall assemblies as a whole. Individual components of the wall are not considered, rather the entire exterior wall assembly is evaluated for compliance with the standard. Deviation from NFPA 285 Assemblies The use of Engineering Judgements (Ejs) for NFPA 285 compliance is a well-debated topic in the design industry. On one hand, it can be impractical to test an exterior wall assembly with every possible variation of material and component (remember that NFPA 285 is a full-scale test of a specific wall assembly). But on the other hand, it can be difficult to judge how variation from a tested assembly will impact performance. While there are many exterior wall assemblies that have passed the NFPA 285 test, in my experience, many designers choose an assembly that has not been specifically tested. Many manufacturers of exterior wall products will obtain a testing report from ICC Engineering Services (an ICC ES Report, or something similar from another testing agency) that claims the product would pass NFPA 285 if tested. These reports, which essentially amount to a generalized EJ, are typically based on substituting one or more products into a wall assembly that has passed NFPA 285. If the EJ route is chosen, the EJ should be provided by a qualified design professional, such as a licensed fire protection engineer with experience in the evaluation of exterior wall assemblies. NFPA 285 vs. ASTM E119 NFPA 285 is different from ASTM E119, the test most commonly used to establish fire-resistance ratings for wall assemblies. This means that if your exterior wall is required to have a fire resistance rating, it also needs to have been tested per ASTM E119. Unfortunately, there are many walls that have a fire-resistance rating per ASTM E119 but do not pass NFPA 285. Similarly, there are walls that comply with NFPA 285 but may not be tested to ASTM E119. This means that if your exterior wall is required to have a fire resistance rating and comply with NFPA 285, there are at least four potential code paths available:
Note that the acceptance of the last two items will vary by jurisdiction. In my experience, most AHJs are satisfied by an ICC ESR report, but the acceptance of EJs can vary greatly. See the section below for more on Ejs. Finding NFPA 285 Wall Assemblies To my knowledge, the best place to find wall assemblies that have been tested to NFPA 285 is the UL database. You can search “FWFO” in the UL directory to find the list, or checkout the database below of all UL-listed assemblies. As mentioned earlier, many designers use the Engineering Judgement route to demonstrate NFPA 285 compliance. Wall assemblies using this code path are not listed in the above UL database.
Changes to the 2019 Edition The 2019 edition has been updated with a new title, now allowing for load-bearing walls, but has also been updated with a few key technical changes. A few notable changes:
It’s crucial to note that the 2019 testing requirements are in many ways more rigorous than past editions. Wall assemblies that have passed earlier editions of NFPA 285 may not comply with the 2019 edition.
4 Comments
In almost every building, owners or tenants have a need for some level of security or access control. The IBC covers a wide range of door locking and control techniques, but the shear number of sections and underlying requirements can be tough to digest. Many folks have trouble knowing which code sections apply, and even if the correct section is identified, it can be a challenge to understand the requirements.
In this post, I take a number of these door locking requirements and translate them into (hopefully) more clear and concise language. I also provide some general commentary on my experience in using each type of door/locking arrangement. References are provided to the last 3 editions of the IBC. Click one of the door/lock types in table below to jump to that section.
Revolving Doors
Many designers don't realize that a revolving door can be used in an egress path, as long as certain requirements are met.
All revolving doors must meet the following requirements, but be sure to check out the paragraph below this one for additional requirements for egress/non-egress doors.
|
Auto/Power Revolving Doors
|
Door Diameter (Feet)
|
Max Speed (RPM)
|
8
|
7.2
|
9
|
6.4
|
10
|
5.7
|
11
|
5.2
|
12
|
4.8
|
12.5
|
4.6
|
14
|
4.1
|
16
|
3.6
|
17
|
3.4
|
18
|
3.2
|
20
|
2.9
|
24
|
2.4
|
- Count towards no more than 50% or required egress width or capacity.
- Each door counts towards a maximum of 50 occupants when performing egress calculations.
- Maximum breakout force of 130 pounds.
Revolving doors that are not egress components must have a breakout force of 180 pounds or less. A breakout force of more than 180 pounds is permitted if the breakout force reduces to 130 pounds or less under one of the following conditions:
- Door power failure
- Sprinkler system activation
- Smoke detector activation with 75 feet of the revolving doors
- Activation of a manual control switch in a clearly identified location
Power-Operated Doors
Power-operated swinging doors, power-operated sliding doors and power-operated folding doors must comply with BHMA A156.10. Power-assisted swinging doors and low-energy power-operated swinging doors must comply with BHMA A156.19. (2018 and Beyond): Low-energy power-operated sliding doors and low-energy power-operated folding doors must comply with BHMA A156.38.
Exceptions to the above requirements:
- Group I-2 occupancies
- Special purpose horizontal sliding, accordion or folding doors (see related section in this article)
- For a biparting door in the emergency breakout mode, a door leaf located within a multiple-leaf opening is exempt from the minimum 32-inch single-leaf requirement, provided that a minimum 32-inch clear opening is provided when the two biparting leaves meeting in the center are broken out.
Special Purpose Horizontal Sliding, Accordion or Folding Doors
- The doors are power operated and are capable of being operated manually in the event of power failure.
- The doors are openable by a simple method from both sides without special knowledge or effort.
- The force required to operate the door cannot exceed 30 pounds to set the door in motion and 15 pounds to close the door or open it to the minimum required width.
- The door must be openable with a maximum force of 15 pounds when a force of 250 pounds is applied perpendicular to the door adjacent to the operating device.
- The door assembly must comply with the applicable fire protection rating and, where rated, must be:
- Self-closing or automatic closing by smoke detection in accordance with IBC 716.2.6.6.
- Installed in accordance with NFPA 80.
- Comply with IBC 716.
- The door assembly must have an integrated standby power supply.
- The door assembly power supply must be electrically supervised.
- The door must open to the minimum required width within 10 seconds of the operating device.
Locking Arrangements in Educational Occupancies
- The door is capable of being unlocked from outside the room with a key or other approved method. Remote door unlocking is permitted in addition to the key.
- The door is openable from within the room per IBC 1010.2
- Modification are not permitted to listed panic hardware, fire door hardware or closers.
- (2021 only) Modifications to fire doors assemblies must be in accordance with NFPA 80.
Security Grilles
Group I-1 and I-2 Controlled Egress Doors
- The door must unlock upon actuation of the sprinkler or smoke detection system.
- The door must unlock upon power loss.
- The door must have an unlocking switch, located at the fire command center, nursing station or other approved location, that directly breaks power to the lock.
- No more than one controlled egress door before reaching an exit
- Door unlocking procures must be included and approved in the required Fire Code emergency planning (see IFC Chapter 4).
- All clinical staff must have a key or other means to operate the locked door
- Emergency lighting is required at the door.
- The door locking system must be UL 294 listed.
- Areas where persons require restraint or containment as part of the function of a psychiatric treatment area or (2021 only) cognitive treatment area.
- Where a listed egress control system is used to reduce child abduction risk from nursery and obstetric area of a Group I-2 hospital.
Delayed Egress
2015:
Delayed egress locking systems are permitted in any occupancy except Groups A, E or H when the building is fully sprinkler protected per NFPA 13 or provided with smoke/heat detection throughout.
2018 and Beyond:
Delayed egress locking systems are permitted in the following situations when the building is fully sprinkler protected per NFPA 13 or provided with smoke/heat detection throughout.
- Group B, F, I, M, R, S and U
- Group E classrooms with an occupant load less than 50
- In courtrooms, on other than the main exit doors, when the building is fully sprinkler protected per NFPA 13.
The delayed egress locking system must meet all of the following requirements:
- The delay electronics must allow immediate and free egress upon actuation of the sprinkler system or fire detection system.
- The delay electronics must allow immediate and free egress upon power loss.
- The delay electronics must have the capability to be deactivated from the fire command center or other approved location.
- When an effort is applied to the egress door hardware for not more than 3 seconds, an irreversible process must star that allows for the egress door to open in 15 seconds or less. The irreversible process must activate an audible signal near the door. Once the delayed egress door has been deactivated, the door can only be rearmed by manual means.
- Exception: Where approved by the AHJ, a delay of not more than 30 seconds is permitted.
- The egress path cannot pass through more than one delayed egress locking system.
- 2015 Exception: In Groups I-2 or I-3, the egress path can pass through up to two delayed egress locking systems if the combined delay is 30 seconds or less.
- 2018 Exception: In Groups I-2 or I-3, the egress path can pass through up to two delayed egress locking systems if the combined delay is 30 seconds or less. In Groups I-1 or I-4, the egress path can pass through up to two delayed egress locking systems if the combined delay is 30 seconds or less and the building is fully sprinkler protected per NFPA 13.
- 2021 Exception: In Groups I-1 Condition 2, I-2 or I-3, the egress path can pass through up to two delayed egress locking systems if the combined delay is 30 seconds or less. In Groups I-1 Condition 1 or I-4, the egress path can pass through up to two delayed egress locking systems if the combined delay is 30 seconds or less and the building is fully sprinkler protected per NFPA 13.
- A sign must be provided on the door and located above and within 12 inches of the door exit hardware:
- For doors swinging in direction of egress, the sign must read “PUSH UNTIL ALARM SOUNDS. DOOR CAN BE OPENED IN 15 [30] SECONDS.”
- For doors swinging in against the direction of egress, the sign must read “PULL UNTIL ALARM SOUNDS. DOOR CAN BE OPENED IN 15 [30] SECONDS.”
- The sign must comply with the visual character requirements in ICC A117.1.
- Exception: Where approved in Group I occupancies, the sign is not required where care recipients have a clinical needs requiring restraint or containment as part of the function of the treatment area.
- Emergency lighting must be provided on the egress side of the door.
- The delayed egress systems must be UL 294 listed.
Sensor Release of Electrically Locked Doors
2015:
Sensor release locks are permitted on any egress door in Groups A, B, E, I-1, I-2, I-4, M, R-1 or R-2 occupancy.
2018 and Beyond:
Sensor release locks are permitted on any egress door except in Group H occupancies.
Sensor release locks must be installed and operated per the following requirements:
- Sensor installed on egress side of door to detect an occupant approaching the door and cause the electric lock system to unlock.
- Door unlocks upon loss of power or signal to the sensor.
- Door unlocks upon loss of power to the lock or locking system.
- Doors can be unlocked from a manual device located 40” to 48” above the floor and with 5 feet of the doors. The unlocking device must be readily accessible and be clearly identified with a “PUSH TO EXIT” sign. The unlocking device must directly interrupt power to the lock independent of other electronics and keep the door unlocked for at least 30 seconds.
- Door unlocks upon activation of the building fire alarm system and remain unlocked until fire alarm system is reset.
- Door unlocks upon activation of the sprinkler system or fire detection system and remain unlocked until the fire alarm is reset.
- Door lock system must be UL 294 listed.
- (2021 Only) Emergency lighting must be provided on the egress side of the door.
Electromagnetically Locked Doors
- Hardware is affixed directly to the door leaf and has an obvious method of operation under all lighting conditions.
- Hardware can be operated with one hand.
- Operating the door hardware immediately interrupts power to the Mag Lock and unlocks the door immediately.
- Door unlocks upon lows of power to the locking system.
- Where panic or fire exit hardware is required, operation of that hardware also releases the Mag Lock.
- Lock system must be UL 294 listed.
Door Hardware Release of Electrically Locked Doors
- Hardware is affixed directly to the door leaf and has an obvious method of operation under all lighting conditions.
- Hardware can be operated with one hand and meets IBC unlatching requirements.
- Operating the door hardware immediately interrupts power to the lock and unlocks the door immediately.
- Door unlocks upon lows of power to the locking system.
- Where panic or fire exit hardware is required, operation of that hardware also releases the lock.
- Lock system must be UL 294 listed.
Correctional Facilities
- Activation of the building sprinkler system
- Actvaition of a manual fire alarm pull station
- A signal from a constantly attended location.
In the 2015 IBC, use of this provision is limited to Groups A-2, A-3, A-4, B, E, F, I-2, I-3, M and S occupancies within correctional and detention facilities. In 2018 and beyond, use of this section is permitted in any building within a correctional and detention facility.
Stairway Doors
- Stair discharge doors can be locked from the outside (must be unlocked in direction leaving the stair).
- Stair doors in high rise buildings complying with IBC 403.5.3 (see section below).
- (2015 Only): In stairs serving 4 stories or fewer, stair doors can be locked from the inside provide they have the capability of being simultaneously unlocked (without unlatching) by a signal from the fire command center or location inside the main entrance of the building.
- (2018 and Beyond): Stair doors can be locked from the inside provide they have the capability of being simultaneously unlocked (without unlatching) by a signal from the fire command center or location inside the main entrance of the building.
- Stair doors in Group B, F, M and S occupancies where the only interior access to a tenant space is from the exit stair can be locked from the inside of the stair (must be unlocked in direction of egress).
- Stair doors in Group R-2 dwelling units where the only interior access to the unit is from the exit stair can be locked from the inside of the stair (must be unlocked in direction of egress).
In high rise buildings, stairway doors can be unlocked from the stairway side provided they have the capability of being unlocked (without unlatching) by a signal from the fire command center. when this provision is used, a telephone or other two-way communication system connected to a constantly attended location is required on every fifth floor in every stairway with locked doors.
Panic and Fire Exit Hardware
Fire Resistance Rating
Functionally, these tests measure an opening protective's ability to stop the transmission of smoke/flames AND to limit the transmission of radiant heat. In order to pass ASTM E119 or UL 263, assemblies must limit the temperature rise on the non-fire side of wall/floor to 250 degrees or less.
Any fire-rated glazing assembly, whether a fire-resistance-rated assembly or fire-protection-rated assembly, is required to be labelled per IBC 716.1.2.2. The markings for these assemblies are shown in IBC Table 716.1(1) and replicated in the table provided below. For fire-resistance-rated glazing, you are looking for markings containing either a "W" or "F". If the marking does not contain either of these letters, the assembly is not fire-resistance-rated. Fire doors are required to be labelled per the requirements of NFPA 80.
Test |
Marking |
Definition |
ASTM E119 or UL 263 |
W |
Meets wall assembly criteria |
ASTM E119 or UL 263 |
F |
Meets floor/ceiling assembly criteria. |
NFPA 257 or UL 9 |
OH |
Meets fire window assembly critiera including host stream |
NFPA 252 or UL 10B or UL 10C |
D |
Meets fire door assembly criteria. |
NFPA 252 or UL 10B or UL 10C |
H |
Meets fire door assembly hose stream test. |
NFPA 252 or UL 10B or UL 10C |
T |
Meets 450 degree temperature rise criteria for 30 minutes. |
- |
XXX |
The time in minutes of the rating of the glazing assembly. |
Fire Protection Rating
- NFPA 252, Standard Methods of Fire Tests of Door Assemblies
- NFPA 257, Standard on Fire Tests for Window and Glass Block Assemblies
- UL 9, Standard for Safety Fire Tests of Window Assemblies
- UL 10B, Standard for Fire Tests of Door Assemblies
- UL 10C, Standard for Positive Pressure Fire Tests of Door Assemblies
Functionally, these tests measure an opening protective's ability to stop the transmission of smoke/flames but do not test for the transmission of radiant heat. There are a number of limitations on the size and use of fire-protection-rated assemblies.
Area Limitations
Fire-protection-rated openings have area limitations as indicated in the table below. Remember that these apply only to fire-protection-rated assemblies. Fire-resistance-rated opening protectives are treated no differently from the wall itself and are not limited in area.
Type of Opening Protective |
Type of Wall |
Area Limitation |
Exceptions |
IBC Reference |
Fire Door |
Fire Wall |
156 SF per opening 25% of the length of the wall |
Not limited to 156 SF when both buildings are fully-sprinklered per NFPA 13 |
706.8 |
Fire Door |
Fire Barrier |
156 SF per opening 25% of the length of the wall |
Not limited to 156 SF when both buildings are fully-sprinklered per NFPA 13; No area limitations for fire doors serving rated stairs/ramps |
707.6 |
Fire Window |
Fire Barrier |
156 SF per opening 25% of the length of the wall |
Not limited to 25% of the wall when used in atrium separation walls |
707.6 |
Fire Window |
All |
25% of the wall area |
- |
716.3.2.1.2 |
In interior fire doors that require a 1-hour rating or greater, fire-protection-rated glazing is permitted in the door vision panel up to 100 square inches. The glazing in the door vision panel is required to pass the hose stream test and bear the "D" and "H" markings. The duration (in hours) of the required rating depends on the type and rating of the wall itself - specific requirements are provided in IBC Table 716.1(2). If a vision panel greater than 100 square inches in area is desired, the vision panel must be fire-resistance-rated glazing and bear the "W" marking. Additionally, vision panels exceeding this area in exit stairways, ramps and passageways must meet the maximum temperature rise criteria of 450 degrees after 30 minutes and bear the "T" marking. There is an exception for this temperature rise criteria if the building is fully-sprinkler protected in accordance with NFPA 13 or 13R. Finally, sidelights and transoms adjacent to fire doors that require a 1 hour rating or greater are required to have a fire-resistance-rating equal to that of the wall itself; fire-protection-rated glazing is not permitted in these.
If the fire door requires a 45 minute rating or less, fire-protection-rated glazing is permitted in the door vision panel up to the maximum size tested. There is no requirement for fire-resistance-rated glazing in such doors. Sidelights and transoms adjacent to these doors are required to have a fire protection rating of either 20 or 45 minutes depending on the location. Refer to IBC Table 716.1(2) for the specific requirements.
Fire doors in rated exterior walls have slightly different requirements. If the exterior wall has a rating greater than 2 hours, the fire door is required to have at least a 90-minute rating and a fire-protection-rated vision panel is permitted up to 100 square inches in area. Any sidelights and transoms are required to have a fire-resistance-rating the same as the wall itself.
Exterior walls rated 2 hours or less are permitted to have fire-protection-rated glazing in the door vision panel, sidelight and transom. The rating requirement for these elements is the same as the door itself.
Fire Windows
Fire-protection-rated glazing is permitted in certain fire windows in interior wall assemblies, up to a maximum rating of 45 minutes. Fire windows in fire walls and fire barriers (excluding atrium separation, incidental use separations and occupancy separations) are required to have fire-resistance rated glazing. Refer to the table below, based on requirements form IBC Table 716.1(3). Note that walls allowing fire-protection-rated glazing can be provided with fire-resistance-rated glazing as indicated, but this is not required.
Type of Wall Assembly |
Required Wall Rating |
Minimum Fire-Protection-Rating Glazing |
Minimum Fire-Resistance-Rated Glazing |
Fire Wall |
All |
Not Permitted |
Same as wall rating |
Fire Barriers* |
All* |
Not Permitted |
Same as wall rating |
Atrium Separations, Incidental Use Separations, Mixed Occupancy Separations |
1 |
45 minutes |
1 hour |
Fire Partitions |
1 |
45 minutes |
1 hour |
Fire Partitions |
30 minutes |
20 minutes |
30 minutes |
Smoke Barriers |
1 |
45 minutes |
1 hour |
Fire-protection-rated glazing is permitted in all fire windows in exterior walls, as described in the table below. IBC Table 705.8 provides requirements for opening protectives in exterior walls, so be sure to refer there as well. Depending on the fire separation distance, you may be permitted to have unprotected openings in a rated exterior walls. Conversely, if the fire separation distance is less than 3 feet, you are not permitted to have any openings in the exterior wall, even if they have a fire protection rating. Fire-resistance-rated glazing is always permitted since it must meet the same test criteria as the wall itself.
Type of Wall Assembly |
Required Wall Rating |
Minimum Fire-Protection-Rated Glazing |
Minimum Fire-Resistance-Rated Glazing |
Exterior Walls |
Greater than 1 |
1.5 hours |
Same as wall rating |
Exterior Walls |
1 hour |
45 minutes |
1 hour |
Exterior Walls |
30 minutes |
20 minutes |
30 minutes |
Summary
Starting Point: Is a Fire Alarm System Required?
Assuming the applicable code is the IBC (all references here are to the 2018 IBC), your first step is to check Section 907.2 to determine if a fire alarm system is required for your building. This section requires a fire alarm system based on occupancy type and other building criteria, such as classification as a high-rise building. In some instances, 907.2 requires a manual fire alarm system (pull stations) and in others a smoke detection system. For the purposes of this article though, the main concern is whether any type of fire alarm system is required at all. That's because, according to IBC 907.2, if a fire alarm system is required by Sections 907.2.1 through 907.2.23, occupant notification is required.
Fire alarm equipment required outside of Section 907.2 such as duct smoke detectors or elevator emergency operations would not trigger a requirement for strobes.
Fire Alarm Requirements by Occupancy
Occupancy |
Trigger for Requiring Fire Alarm System |
2018 IBC Reference |
A |
Occupant load greater than 299 or greater than 100 on floors above or below exit discharge. |
907.2.1 |
B |
Occupant load greater than 499 or greater than 100 on floors above or below exit discharge. Always required for ambulatory care facilities. |
907.2.2 |
E |
Occupant load greater than 50. |
907.2.3 |
F |
Occupant load greater than 499 on floors above or below exit discharge AND 2 or more stories. |
907.2.4 |
H |
Group H-5 occupancies and in occupancies used for the manufacture of organic coatings or containing highly toxic gases, organic peroxides or oxidizers. |
907.2.5 |
I |
Required in all Group I occupancies. Occupant notification not required where private mode signaling is approved by code official. |
907.2.6 |
M |
Occupant load greater than 499 or greater than 100 on floors above or below exit discharge. |
907.2.7 |
R-1 |
Required in all Group R-1 occupancies. There is an exception for buildings 2 stories and smaller with sleeping units that have direct exterior exits. |
907.2.8 |
R-2 |
Required in R-2 occupancies that are 3 or more stories above lowest exit discharge, 2 or more stories below highest exit discharge or greater than 16 units. There are exceptions for buildings 2 stories and smaller with sleeping units that have direct exterior exits OR sprinklered occupancies with no interior corridors or open corridors. Also required in Group R-2 college and university buildings. |
907.2.9 |
Fire Alarm Requirements for Specific Situations
Criteria |
Trigger for Requiring Fire Alarm System |
2018 IBC Reference |
Special Amusement Buildings |
Required in all special amusement buildings. |
907.2.11 |
High-Rise Buildings |
Required in all high-rise buildings. |
907.2.12 |
Atriums |
Required in atriums connection more than two stories. |
907.2.13 |
High-Piled Combustible Storage |
Required in all high-piled combustible storage areas. |
907.2.14 |
Aerosol Storage |
Required in some aerosol product rooms and warehouse containing aerosol products, refer to IFC Chapter 30. |
907.2.15 |
Lumber, Wood Structural Panel and Veneer Mills |
Required in all lumber, wood structural panel and veneer mills. |
907.2.16 |
Underground Buildings |
Required in underground buildings provided with a smoke control system AND deep underground buildings. |
907.2.17 and 907.2.18 |
Covered and Open Mall Buildings |
Required when total floor area exceeds 50,000 square feet. |
907.2.19 |
Airport Traffic Control Towers |
Required in all airport traffic control towers. |
907.2.21 |
Battery Rooms |
Required when battery systems exceed the capacity found in IFC Table 1206.2. |
907.2.22 |
Capacitor Energy Storage Systems |
Required when capacitor energy storage systems exceed 3kWh capacity. |
907.2.23 |
Step Two: Are Strobes Required?
Public Uses Areas and Common Use Areas
Strobes are required in public and common use areas, with the exception of employee work areas, which are permitted to be provided with spare circuit capacity to account for future addition of strobes if needed for hearing-impaired employees. Public use and common use are defined terms in the IBC:
Common Use: Interior or exterior circulation paths, rooms, spaces or elements that are not for public use and are made available for the shared use of two or more people.
Public Use Areas: Interior or exterior rooms or spaces that are made available to the general public.
Examples of spaces that fall under one of these categories are: lobbies, corridors, circulation areas, meeting rooms, conference rooms, assembly areas, public or shared restrooms, retail spaces, and classroom. This is by no means an exhaustive list, so you'll need to consider each space in your building to verify if it falls under the definition of public use or common use.
Groups I-1 and R-1
Strobes are required in a certain percentage of dwelling and sleeping units in Group I-1 and R-2 occupancies. Refer to the table below, replicated from IBC Table 907.5.2.3.2.
Number of Units |
Units with Visible Alarms |
6 to 25 |
2 |
26 to 50 |
4 |
51 to 75 |
7 |
76 to 100 |
9 |
101 to 150 |
12 |
151 to 200 |
14 |
201 to 300 |
17 |
301 to 400 |
20 |
401 to 500 |
22 |
501 to 1,000 |
5% of total |
1,001 and over |
50 plus 3 for each 100 over 1,000 |
Group R-2 occupancies requiring a fire alarm system must have the capability to support strobes appliances in the future. The intent is that the fire alarm system has the capability to be modified if a hearing impaired occupant were to move into the sleeping or dwelling unit.
Step 3: Requirements Outside the IBC
Assuming you are required to provide a fire alarm system, the requirements of NFPA 72 would apply (ADAAG would also apply, assuming your building is required to comply with the Americans with Disabilities Act (ADA), which is a longer discussion for another article). In most cases, if you provide a fire alarm system and a strobe layout that complies with the IBC and NFPA 72, you will meet the requirements of ADAAG.
Summary
- Determine if a fire alarm system is required for your occupancy and/or specific building situation in the applicable codes.
- If a fire alarm system is required, determine if visible notification (strobes) are required. The most common drivers are:
- Public use and common use areas
- Group I-1 and R-1 sleeping/dwelling units
- Check other requirements. These could be additional local codes/standards, particularly amendments or additional requirements to NFPA 72 or ADAAG.
Group I-2, Condition 1: "facilities that provide nursing and medical care but do not provide emergency care, surgery, obstetrics or in-patient stabilization units for psychiatric or detoxification, including but not limited to nursing homes and foster care facilities."
Group I-2, Condition 2: "facilities that provide nursing and medical care and could provide emergency care, surgery, obstetrics or in-patient stabilization units for psychiatric or detoxification, including but not limited to hospitals."
Corridor Doors
First, Section 407.3.1.1 has been added for corridor doors that are not required to have a fire protection rating. Generally, Group I-2 corridor walls are not required to have a fire-resistance rating unless they are part of an enclosure for an exit or vertical opening, or if they are separating an incidental use room that requires a rating per IBC 509.4.
This new section now addresses the following:
- Solid doors, which are now specifically required to have close fitting operational tolerances, head and jamb stops
- Dutch-style doors, which are now specifically allow, but must have the following features:
- An astragal, rabbit or bevel at the meeting edge of the upper and lower sections
- Latching hardware on both the upper and lower sections
- Hardware that connects the upper and lower sections, allowing them to function as a single leaf
- Makeup air: when used to provide makeup air for exhaust systems (per Section 1020.6 Exception 1), doors are now specifically permitted to have either louvers OR up a 2/3" bottom gap
Second, Section 407.6.1 has been added for automatic-closing doors on hold-opens. Previously, these doors were only required to close upon actuation of a smoke detector or loss of power to the hold-open or smoke detector. Now, these doors must also close upon activation of the fire alarm system or sprinkler system.
Exit Access Through Care Suites
Nursing Home Cooking Facilities
Under the 2021 IBC, these requirements are now organized as follows:
Nursing Home Cooking Facilities (407.2.6): In Group I-2, Condition 1 occupancies, spaces containing a cooking facility with a domestic cooking appliance are permitted to be open to the corridor when all of the following criteria are met:
- No more than 30 care recipients in the smoke compartment containing the cooking facility (or served by the facility)
- No more than one cooking facility per smoke compartment
- A clearly delineated corridor space is provided
- The cooking facility can not obstruct access to the exit
- The cooking appliance must comply with 407.2.7
Domestic Cooking Appliances (407.2.7): In Group I-2 occupancies, cooking appliances in domestic cooking facilities must comply with the following:
- Appliances limited to ovens, cooktops, ranges, warmers and microwaves
- Domestic cooking hood installed in accordance with IMC 505 provided over cooktops and ranges
- Cooktops and ranges protected with Section 904.14.1, which requires either a fire extinguishing system in the hood OR a burner that is listed to prevent ignition of cooking oils. While the code does not give a specific standard for the listing, any appliances listed to the new Section 60A in UL 858 would meet this criteria. In the US, electric burners sold after April 2019 are required to meet this criteria.
- This requirement does not apply for cooktops and ranges used for care recipient training or nutritional counseling purposes
- A fuel/electrical power shutoff for the cooking equipment is provided in a staff-only area
- A timer is provided that automatically deactivates the equipment in 120 minutes or less
- A fire extinguisher is provided within 30 feet of each domestic cooking appliance
Conclusion
Occupied Roofs Under the 2018 IBC
First, IBC 302.1 has been updated with specific requirements for classifying an occupied roof space:
Where a structure is proposed for a purpose that is not specifically listed in this section, such structure shall be classified in the occupancy it most nearly resembles based on the fire safety and relative hazard. Occupied roofs shall be classified in the group that the occupancy most nearly resembles, according to the fire safety and relative hazard, and shall comply with Section 503.1.4. (Excerpt from 2018 IBC 302.1) |
Next, IBC 503.1.4 brings in a major new requirement:
A roof level or portion thereof shall be permitted to be used as an occupied roof provided the occupancy of the roof is an occupancy that is permitted by Table 504.4 for the story immediately below the roof. The area of the occupied roofs shall not be included in the building area as regulated by Section 506. |
- If your building if fully sprinkler-protected (NFPA or 13R) and you have fire alarm notification on the occupied roof, you are permitted to have any occupancy on the occupied roof.
- If your building is Type I or II construction, you are permitted to have assembly occupancies on the roof of parking garages.
Take the image below for an example, a 4 story building consisting of Type IIIA construction. If the building is fully sprinkler protected in accordance with NFPA 13, a Group A-3 occupancy would per permitted on Level 4. As long as occupant notification is provided on the roof, the 2018 IBC now explicitly allows a Group A-3 occupancy on the roof.
The provision of Section 503.1.4.1 do limit elements on the roof to no more than 48" above the roof surface, with exceptions for penthouses, tower, domes, spires and cupolas. If you have elements above this height, the roof would have to be classified as a story. As an example, the overhang in the image above of the Facebook building would likely trigger the roof being classified as a story.
Another common question is whether an occupied roof can trigger classification as a high-rise building. The IBC itself does not address this issue, but this staff opinion from the ICC is very helpful in clarifying the intent. The opinion clearly states, "Just because a roof is an occupied roof does not make it a floor with respect to the definition of a high-rise building. "
Occupied Roofs Under the 2021 IBC
Additionally, the 2021 IBC clarifies that the Exception 1 to 503.1.4 for occupant notification would only require a voice fire alarm system on the roof if the system is required elsewhere in the building. In other words, if you aren't required to have a voice fire alarm in the building, you don't have to provide it on the roof in order to use Exception 1.
Finally, the 2021 IBC updates Section 1511.2.2, Use Limitations for Penthouses, to specifically allow "ancillary spaces used to access elevators and stairways" to be considered part of a penthouse. This means that a stair or elevator tower to the roof will not force an occupied roof to be classified as a story, even though those elements are taller than 48" from the roof surface.

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