Technical detail
Everything that goes into a proper fire alarm installation
Fire alarm installation is not a single product, it is an engineered system whose design must match the building, its occupancy and the risk profile identified in the fire risk assessment. The sections below explain how we specify systems across the property types we work with most often.
Grades explained: A, B, C, D, E, F
Grade A is a fully BS 5839-1 system with control panel, mains-powered detection and standby battery, required for most licensable HMOs and all commercial premises. Grade D systems use mains-powered, interlinked detectors with battery back-up and suit smaller shared houses. We never specify lower grades where a higher grade is mandated, even when a cheaper option is asked for.
Categories: LD1, LD2, LD3, L1–L5
Categories define where detection is placed. LD1 covers all rooms including bedrooms; LD2 covers escape routes plus high-risk rooms; LD3 protects only escape routes. Commercial L1–L5 categories follow the same logic. The right category is dictated by your fire risk assessment, not by budget.
HMO vs. commercial installs
HMO systems prioritise sleeping-risk coverage and inter-flat compartmentation, with sounder levels of 75 dB at the bed-head. Commercial installs add manual call points at every exit, zoning by floor or fire compartment, and often interface relays for door-holders, lift recall and AOV (automatic opening vents).
Wired, wireless and hybrid systems
We fit wired loops as standard for new build and refurbishment, hybrid radio for occupied period properties where chasing cable is impractical, and full wireless EN 54-25 systems for listed buildings. Each has trade-offs in cost, service life and battery replacement schedule that we walk you through at survey.
Integration with emergency lighting and door entry
Where appropriate we tie the fire alarm into emergency lighting test routines, magnetic door retainers and Paxton or similar access control so that all life-safety systems behave correctly on activation.
Materials and manufacturers we standardise on
Hochiki, Apollo, Kentec and Aico for panels and devices, chosen for 10-year-plus parts availability and serviceability. We do not fit cloned panels or grey-import devices that cannot be serviced in five years' time.