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
Fire Alarm Requirements for Specific Situations
In addition to the occupancy requirements above, IBC 907 provides requirements for specific building situations.
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.
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.
The general process for determine strobe requirements is: