The Three W’s of Fire Alarm
The fire alarm industry is a code driven industry. We design, install, and inspect & test fire alarm systems by the codes used in our industry, based on the specific editions adopted by our AHJ. Performance to these codes is a mandatory requirement. Meeting the minimum standards set forth by these codes ensures compliance and provides an appropriate level of life safety.
We like to call these codes we use “The Three W’s of Fire Alarm – What, Where, and Wire.”
The first W -- What -- is the starting point of fire alarm design. It is how the question “WHAT are the fire alarm requirements for the building?” The first W is based on the life safety or building code being enforced by the AHJ. The code being enforced by the AHJ is usually either NFPA 101 (Life Safety Code) or IBC (International Building Code), with the IBC being the more popular option.
Once the appropriate life safety/building code is determined, we then need to determine what version and edition is being used. The version is determined by the AHJ – is the national version of the code being used, or a state or city specific version. State or city specific versions may contain specific modifications and amendments to the national version that only apply to that area. The edition is the year of the code being used. The codes are updated on a 3 year cycle, so it is important to make sure the design is based on the year currently being used.
Since the life safety and building codes cover all aspects of building safety, it is important to know how to navigate to the fire alarm requirements within each code. The IBC is a system centric code, with the fire alarm systems are covered in Section 907. The building requirements are listed alphabetically by the Use Group designation.
NFPA 101 is a occupancy centric code, organized by building occupancy type chapters. Specific requirements for different building life safety features are organized within the chapter. Fire alarm requirements are located in section 3.4 of each occupancy chapter.
IBC and NFPA 101 determine whether or not a building requires a fire alarm system, and then the type of fire alarm system required. These codes answer the questions about whether the building requires pull stations located through the building, or automatic detection (smoke detectors) are required. They also determine whether or not a sprinkler system is required, which can replace both pull stations and smoke detectors.
The second W -- Where -- is the next step in fire alarm design. Once we determine the type of fire alarm required in a building, the next question to answer is “WHERE are the devices located?”. NFPA 72, the National Fire Alarm and Signaling Code answers this question. NFPA 72 determines fire alarm system performance requirements, as well as device location and spacing. NFPA 72 tells us how far apart to space smoke detectors, and how high to mount horn/strobes.
The third W -- Wire -- covers the wiring requirements for the fire alarm system. NFPA 70, the National Electrical Code, governs all electrical wiring – including fire alarm wiring. Chapter 3 covers general wiring and protection requirements, and Article 760 specifically covers fire alarm system wiring. Wiring our fire alarm systems according to the requirements of NFPA 70 ensures code compliance.