What is fire alarmin construction?

Every initiating and notification device, each by type: pull stations, smoke and heat detectors, duct detectors, horn/strobes, and strobe-only units, plus monitor and relay modules for each interface point (sprinkler flow and tamper, elevator recall, smoke dampers, door holders). The FACP, remote annunciator, and NAC power supplies are counted each, and the wiring is measured in linear feet. Programming, testing, and the acceptance test show up as labor lines, not devices, and they are real money.

Both models are common. On many jobs the electrical subcontractor carries fire alarm as a second-tier scope, subbing the design, programming, and final connections to a specialty alarm house while self-performing the rough wiring and device mounting. Other specs require a single licensed fire alarm contractor end to end. Either way, the NFPA 72 shop drawings and the acceptance test sit with the licensed alarm contractor, so the estimator should verify whose number includes them.

An addressable system gives every device a unique address on a signaling loop, so the panel reports exactly which detector tripped and supervises each point individually; nearly all new commercial systems are addressable. A conventional system wires devices into zones and only knows that something in zone 3 activated. Addressable hardware costs more per device but saves wire, since devices daisy-chain on loops, and it slashes troubleshooting time, which is why it wins on anything beyond a small tenant space.