Fire Alarm Systems for Supported Housing
Supported housing normally comprises a form of single-family dwelling, commonly converted for the purpose. It follows that, in the event of fire, anywhere in the property, all residents need to evacuate immediately. Accordingly, given the vulnerable nature of the residents, it will be necessary to provide a very high standard of automatic fire detection. The design of the system should be as set out in the following paragraphs, but may be varied if this is justified by a fire risk assessment carried out by a competent person, taking into account the nature of the residents for whom the premises are intended (though the standard of system should not be reduced solely on the basis that this is a higher standard than is necessary at the time of the fire risk assessment).
The extent of automatic fire detection should comply with the recommendations of BS 5839-6: 2013 for a Category LD1 system (which is the highest category for protection of life in domestic premises). Smoke detectors should be provided in all circulation spaces, and in all rooms within the property, other than kitchens, toilets, shower rooms and bathrooms. In kitchens, heat detection should be provided. However, where a kitchen or dining room forms an inner room accessed only from the lounge, the detector in the inner room may be omitted (rendering the system Category as LD2).
No fire detection need be provided in toilets, shower rooms and bathrooms or, normally, in cupboards. There will normally be no need for fire detection within roof voids, unless there are specific, significant fire hazards within a roof void, such as gas boilers or electrical equipment for photovoltaic systems. All smoke detectors within circulation spaces, or areas into which kitchens open, should be of the optical type; alternatively, appropriate multi-sensor detectors may be used.
In single storey premises and other premises with no more than four bedrooms (including staff bedrooms), fire detection may comprise a Grade D system, as defined in BS 5839-6: 2013 (i.e. the detectors may comprise mains-operated domestic smoke alarms with internal standby batteries or capacitors). All smoke alarms should be interlinked by either wiring or radio transmission, so that, when fire is detected by one smoke alarm, all smoke alarms in the property sound simultaneously. Unless there is at least one member of staff present (whether awake or asleep) on a 24-hour basis, the standby batteries should be tamper proof (e.g. cells soldered to a printed circuit board, capacitors or PP3-type batteries that are fixed in place and cannot readily be removed).
Accordingly, in premises of two or more storeys with more than four bedrooms (including staff bedrooms), domestic smoke alarms should not normally be regarded as adequate. The fire detection in these premises should comprise a Grade A system, as defined in BS 5839-6, with control and indicating equipment sited within the ground floor circulation space, fire detectors and fire alarm sounders. Where there is, at any time, less than two members of staff on duty, either the system should be addressable or there should be remote indicator lamps outside the entrance door to each resident’s accommodation, so that the location of a fire can be quickly identified. However, if existing premises of not more than two storeys are provided with sufficient mains-operated smoke alarms (with standby batteries or capacitors), these need not be replaced with a Grade A system until the smoke alarms reach the end of their useful life.
To satisfy the recommendations of BS 5839-6, the standby batteries for a Grade A system should be able to operate the system for 72 hours in the event of mains failure, after which there should be sufficient capacity to sound an evacuation signal for 15 minutes. However, in premises with at least one member of staff present (whether awake or asleep) on a 24-hour basis, the period of 72 hours may be reduced to 24 hours.
BS 5839-6 recommends that the sound pressure level of the fire alarm signal should be at least 85dB(A) at the open doorway of every bedroom, but might need to be a higher level of 75dB(A) at the bedhead of each bedroom in a house in multiple occupation. In practice, this higher level will, in any case, be achieved in Grade D systems in which smoke alarms are provided in each bedroom, as each smoke alarm acts as both a fire detector and sounder. In the case of Grade A systems, fire alarm sounders (which may be incorporated in the base of each detector) should be installed in each bedroom.
In areas other than bedrooms, the sound pressure level of the fire alarm system need not be as high as found in commercial premises; typically, a sound pressure level of 55dB(A) will be sufficient. However, care should be taken to ensure that the sound pressure level, frequency and other characteristics of alarm sounders (whether in the form of smoke alarms or independent sounders) do not cause adverse reaction that would be detrimental to the evacuation of residents who are sensitive to alarm signals as the result of mental health problems. In such cases, alternative forms of warning, such as visual alarm devices or voice sounders, might need to be considered.
People with hearing loss often have difficulty in hearing high frequencies, such as those produced by domestic smoke alarms; in addition, high frequencies are also subject to greater attenuation by partitions, walls and doors. For residents who are hard of hearing, lower frequency alarm signals are, therefore, preferable. Lower frequencies are produced by the fire alarm sounders used in Grade A systems or low frequency sounders that can be linked to domestic smoke alarms (e.g. by radio).
Where residents are deaf or severely hard of hearing, additional fire warning devices should be provided to alert them in the event of fire. For residents who need to be warned when they are awake, visual alarm devices (flashing beacons) are normally suitable. If it is necessary to rouse deaf or severely hard of hearing people when they are asleep, vibrating pads, linked to the fire alarm system, should be used for this purpose; these are placed under pillows or mattresses.
If supported housing takes the form of small flats or bedsits, in which smoke detectors might result in false alarms (e.g. as a result of smoking or cooking), it is acceptable for the fire detection and alarm system to comprise a “mixed system” (as defined in BS 5939-6), provided residents can respond appropriately to the signal from a smoke alarm in their own accommodation.
In this arrangement (which is commonly used in houses in multiple occupation), warning of a resident in the event of fire within their own accommodation is given by a Grade D system, comprising mains-powered domestic smoke and heat alarms (with standby batteries or capacitors). Within the resident’s accommodation, all smoke and heat alarms are interlinked. In the common parts, a Grade A system is provided, with smoke detectors in all circulation areas and rooms, other than toilets, shower rooms and bathrooms. Suitably sited sounders and heat detectors forming part of the Grade A system are installed in each resident’s accommodation. Heat detectors rarely cause false alarms, and are much slower to operate than smoke detectors, but will give a warning to other residents in the event of a significant fire.
A mixed system, as described above, is only suitable for a property in which, when fire occurs, there is an immediate and simultaneous evacuation throughout the property. If a ‘stay put’ strategy were adopted (as in the case of sheltered housing), a mixed system is suitable only if, additionally, the smoke and heat alarms in each resident’s accommodation transmit a signal to alert staff or an alarm receiving centre, so that the fire and rescue service are summoned; heat detectors alone are not sufficiently sensitive for this purpose
In supported housing with a simultaneous evacuation strategy, it is not normally necessary for alarm signals to be transmitted to an alarm receiving centre, particularly if one or more members of staff (whether awake or asleep) are present on a 24-hour basis. However, where there is no 24-hour staff presence, or there is any uncertainty as to whether, in the event of a confirmed fire, staff will summon the fire and rescue service immediately, remote transmission of fire alarm signals to an alarm receiving centre may be appropriate, so that early attendance of the fire and rescue service is facilitated in the event of fire. In this case, consideration needs to be given to measures or arrangements to avoid summoning of the fire and rescue service in the event of false alarms.
In supported housing, manual call points will not normally be necessary; in particular, manual call points need never be provided if a Grade D fire detection and alarm system would satisfy the recommendations of this guide. However, the provision of manual call points should be considered if a verbal warning of fire, shouted by occupants, is unlikely to be effective; this is only likely to be the case in supported housing with more than six bedrooms or more than three storeys.