In the past I have focused on the devices and appliances required in a fire alarm system, and now we can look at the full system requirements. The minimum requirements for the application, installation and performance of alarm and signaling systems within the protected premises is covered in NFPA 72, Chapter 23, Protected Premises Alarm and Signaling Systems. 

However, the minimum requirements rarely address any site-specific needs, or the physical and operational conditions present. And I am guessing you do not have anyone on your design team with the knowledge to address life safety, property protection and mission continuity above and beyond the minimum code requirements. A complete review of the code will help.

In addition to Chapter 23 requirements, there is Annex C, System Performance and Design Guide. Although the annex material is not enforceable, Annex C provides an outline for system designers to follow so the construction features of the facility, capabilities of emergency responders, desired features of the fire alarm system, size and use of the building, and other factors can be considered in the design decision process.

As stated in the scope of Annex C, “This guidance suggests potential system characteristics to enhanced system performance for protection of life, mission, and property in high-profile and other critical buildings, including signaling path integrity, redundancies, survivability, backup fire control stations, nonerasable logs, multiple information stations, and the benefits of networked and peer-to-peer configurations.”

Many items included in the design guide provide “additional considerations for users of NFPA 72 when planning, designing, and installing protected premises fire alarm systems for buildings that might be unusual in scale, mission, use, symbolism, or other critical or high-profile characteristics.”

Chapter 23 addresses the following topics:

• Software and firmware control
• Required and nonrequired (i.e., voluntary) systems
• System performance and integrity, including circuit designations, pathway classifications and performance of initiating device circuits, signaling line circuits and notification appliance circuits
• System requirements, such as actuation time, presignal features, positive alarm sequence, interconnected fire alarm control units, combination systems, system inputs and outputs, and remote access
• Reference to Chapter 24 for in-building fire emergency voice/alarm communication systems
• Requirements for fire alarm systems using tone notification, suppression system activation, off-premises signal transmission, guard’s tour supervisory service, suppressed (exception reporting) signal systems, protected premises emergency control functions and low-power radio (wireless) systems

Almost every owner initially asks me to design a code–compliant minimum system. Before I accept that instruction, I start a conversation regarding the outlined subjects in Annex C. I explain that the size of the building will influence my decisions on the fire alarm system operating characteristics, control functions, circuit integrity, annunciation, notification and other factors for protection of life, property or the building’s mission. 

I also explain that I have already queried the fire department to determine their response time to the building. Time is the unit of measurement here. In addition to notifying the occupants, it is important to provide as much lead time as possible for first responders. If I plan to use the minimum detection and the fire size continues to grow exponentially before the first responders arrive on scene, the system will be of limited, if any, benefit. Additionally, the fire department might want more than one response point to the building, depending on where the fire is first detected. 

I also determine if the fire service response area will be the location of the fire command center. Remote fire alarm system annunciators are there for first responders to save time in locating the fire. I want to know if the command center is the only location where I need to provide control functions for the entire building or for a portion of the building.

Find out if the owner has an emergency response plan. You will want to ensure the owner knows the importance of personnel’s availability and responsibility, occupant mobility, whether the building security or management team members will investigate each alarm activation before calling the fire department and how the owner will communicate a true alarm condition to building occupants and first responders. 

You’ll also need to ask some important questions. Will the system cause an evacuation alarm or communicate other information for relocation? If it is an emergency communication system, will you need to have the messages in multiple languages?

The guide also includes the following points to consider in the design process: evacuation/relocation, survivability, building systems control, fire scene operations, external response, resources available, fire department notification, knowledge of premises, and communications and control.

Annex C has good information and topics to convince the owner to install a robust fire alarm system. 

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