Houses in Multiple Occupation fire safety guidance

Grades of automatic fire detection and warning systems as specified in the latest edition of BS 5839: part 6

In grades D, E, and F, where more than one alarm is installed they must be interlinked.

Grade A

A fire detection and alarm system that is designed and installed in accordance with the recommendations of BS 5839: part 1 (2002), except clauses relating to alarm audibility, alarm warnings for the hearing-impaired, standby supplies, manual call points and radio-linked systems, which are replaced by part 6. This comprises a system of electrically operated smoke and/or heat detectors which are linked to a control panel. The control panel must conform to current BS 5839: part 4 (or equivalent). In general the system must incorporate manual call points which should be located next to final exits, and, in larger multi-storey properties, on each landing. The alarm signal must achieve sound levels of not less than 65dB (A) in all accessible parts of the building and not less than 75dB (A) at all bed-heads when all doors are shut, to arouse sleeping persons.

Grade B

A fire detection and alarm system including detectors (other than smoke or heat alarms), alarm sounders and control and indicating equipment which either conforms to BS EN 54-2 (power supply to BS EN 54-4) or to a simpler type laid out in annexe C of BS 5839: part 6.

Grade C

A system of fire detectors and sounders (which may be combined in the form of smoke or heat alarms) connected to a common power supply with both mains and a standby supply, with an element of central control - for example a small dedicated fire control panel.

Grade D

A system of one or more mains-powered smoke (or heat) alarms each with integral battery standby supply. These are designed to operate in the event of mains failure and therefore could be connected to the local lighting circuit rather than an independent circuit at the dwelling's main distribution board. There is no control panel.

Grade E

A system of one or more mains-powered smoke (or heat) alarms with no standby power supply. This grade of system will not function if mains power is disconnected or interrupted. It must therefore be wired to a dedicated circuit at the dwelling's main distribution board.

Grade F

A system of one or more battery-powered smoke alarms. These are not recommended in HMOs.

Levels of coverage of automatic fire detection and warning systems as specified in BS 5839: part 6 (2004)

LD1 coverage

A system installed throughout the dwelling incorporating detectors in all circulation spaces that form part of the protected escape routes from the dwelling, and in all rooms and areas in which fire might start.

LD2 coverage

A system incorporating detectors in all circulation spaces that form part of the protected escape routes from the dwelling and in all rooms or areas that present a high fire risk to occupants i.e. risk rooms.

LD3 coverage

A system incorporating detectors in circulation spaces that form part of the protected escape routes from the dwelling only.