Where are Fire Alarm Strobes Required?

If you have been involved in the design or installation of a fire alarm system, whether as an architect, engineer, or owner, you have probably asked the question, "Is a strobe required here?" Like all engineering questions, the answer depends on a number of factors. In this post, I will walk through the code path step-by-step to help you understand where fire alarm strobes are required.

Starting Point: Is a Fire Alarm System Required?

The starting point for determining strobes requirements is the applicable building code for your jurisdiction. If you are in the United States, this is most likely based on the International Building Code (IBC). For projects located elsewhere, this could be NFPA 5000. Buildings owned or operated by the government could also be subject to other requirements, such as the GSA PBS-P100 or UFC 3-600-01. You may also be in a jurisdiction that enforces NFPA 101, which also has requirements for fire alarm systems.

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

In addition to the occupancy requirements above, IBC 907 provides requirements for specific building 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?

Once you have determined that a fire alarm system is required, you'll want to flip ahead a few pages to determine which rooms require strobes. The starting point is IBC 907.5.2.3:

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
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

The final step is to review other documents that could drive strobe requirements. One common question is whether or not ADA Accessibility Guidelines (ADAAG) or NFPA 72 require strobes in certain rooms. Neither of these documents actually require a fire alarm system or strobes to be installed at all. When a fire alarm system is provided, however, ADAAG brings in requirements for where visible notification is required. Similarly, NFPA is only applicable when the IBC or other applicable codes require a fire alarm system.

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

The general process for determine strobe requirements is:

1. Determine if a fire alarm system is required for your occupancy and/or specific building situation in the applicable codes.
2. If a fire alarm system is required, determine if visible notification (strobes) are required. The most common drivers are:
   1. Public use and common use areas
   2. Group I-1 and R-1 sleeping/dwelling units
3. Check other requirements. These could be additional local codes/standards, particularly amendments or additional requirements to NFPA 72 or ADAAG.