BS 5839-6 sets out fire detection for domestic premises, including most houses in multiple occupation. It uses two measures: the grade, which describes the equipment and its power supply, and the category, which describes where the detectors go.
Categories: where detectors go
| Category | Coverage |
|---|---|
| LD3 | Circulation spaces that form the escape route, such as halls and landings |
| LD2 | Everything in LD3, plus rooms where a fire is more likely to start or would be most dangerous, such as the kitchen and main living room |
| LD1 | Detection throughout, in every room where a fire might start, apart from bathrooms, shower rooms and toilets |
Grades: what the system is made of
Grade D1 means mains powered alarms with a tamper proof standby supply, such as a sealed 10 year battery. Grade D2 uses a user replaceable standby battery. Grade F alarms are battery only. Larger HMOs with communal areas may need a Grade A system with a control panel.
Heat, not smoke, in kitchens
Smoke alarms in kitchens cause nuisance alarms, and nuisance alarms get disconnected. Use a heat alarm in kitchens, interlinked with the rest of the system so it sounds throughout the property.
Radio interlinking
Radio interlinked alarms talk to each other without cable runs between them, which saves time and redecoration in occupied buildings. The UltraFire radio interlinked heat alarm links with up to 15 alarms in total.
Who decides
The local authority's licensing conditions and the property's fire risk assessment set the grade and category for an HMO. Confirm what is required before ordering, and remember carbon monoxide alarms where there is a fixed combustion appliance.