While smoke alarms have been credited for bringing down fire deaths in the home, standards and regulations do not always offer uniform guidance. Gerald Jones argues for more consistency.
Most fire deaths and injuries occur in the home and there is no
doubt that working smoke and heat alarms play a major role in saving lives. But there is fundamental disagreement among those who set minimum standards and regulations around the UK about just how many are needed and where best to locate them – both to detect fire and to alert occupants. Worryingly, the different approaches taken seem to be reflected in the latest fire death statistics.
BS 5839-6: 2004 is the current Code of Practice for domestic fire alarm systems, and is well-recognised as the authoritative guidance source for both new and existing dwellings. It points out that Category LD3 – smoke alarms just in corridors – is only intended to protect circulation areas used as escape routes and “might not therefore prevent the death or serious injury of occupants in the room where the fire originates”. Just over half of all domestic fire fatalities occur in the room of fire origination – in the case of bedrooms this rises to 63%. It also stresses that “the time available for evacuation of other areas once the fire is detected in the circulation area might be quite short.” It is for these reasons that it recommends category LD2 for new – and many existing – dwellings as a minimum and wherever “it is intended to protect reliably any occupant in the room where a fire originates”. Category LD2 requires smoke or heat alarms in living rooms and a heat alarm in every kitchen, as well as the usual smoke alarms in circulation areas.
In contrast, the current Building Regulations Approved Document B, Fire Saety – Volume 1, Dwellinghouses'(ADB), which came into effect last April, effectively requires only Category LD3, regarded by many as a deficiency which would be corrected in future. However, recently published government commissioned research looks set to frustrate these demands. The report, BD 2538 Determining the best option for the provision of additional smoke alarms in dwellings and houses, commissioned by Communities and Local Government department (CLG), sets out to resolve issues outstanding from the development of ADB. In addition to the conflicts with BS 5839-6 it also considers issues of audibility for sleeping occupants with an additional smoke alarm in the main bedroom – a sensible proposal included in the draft ADB but subsequently omitted from the final version. The report considered both issues from the perspectives of fire statistics between 1994 and 2002, computer modelling, and a cost benefit analysis. On all fronts, it concludes that adding any more smoke or heat alarms to the minimum ADB requirement would not “lead to any discernable further reductions in risk”, signalling the probability of no change to the next ADB. Many would fundamentally disagree with this conclusion and the resulting misapplication of Category LD3, which relies on assumed defects in, for example, room doors to allow both sound and smoke to pass through.
New methods
But house building today is moving towards modern methods of construction using engineered, high performance components – with government encouragement. While doors may have been considered the weak link in sound reduction, for example, modern, factory-assembled doorsets now consistently provide impressive performance levels: a reduction of 36 decibels (expressed as Rw=36dB) is easily achievable without special measures. In essence, this is achieved by minimising the passage of air (and also smoke) through the doorset. Also, fire-rated doors – needed for rooms off the stairway of three or more storey houses – provide good acoustic insulation by their very nature. Yet BS 5839-6 recommends achieving a sound level of 75 dB(A) at the bedhead and also recommends more than 85 dB(A) at the doorway of each bedroom where doors exceed 20 dB “unless there is a sounder in the bedroom”. As domestic smoke alarms usually generate 85 dB(A), neither of these levels can be achieved in most situations and a bedroom alarm or sounder is justified. In particular, research has shown that young children can sleep through loud alarms, while elderly people and others with hearing impairments may also not respond.
In response to this issue, the ADB consultation draft included a new provision that ‘in order to improve audibility, a smoke alarm should also be fitted in the main (largest) bedroom’ – effectively as a sounder. The same effect can be achieved with some systems using a CO alarm to help protect against carbon monoxide poisoning, while also acting as a sounder to other interconnected smoke/heat alarms. Although again omitted in the final version, this was an important proposal, recognising growing the conflict between greater acoustic privacy and the resulting sound attenuation capabilities of modern partitions and internal doors. This trend for acoustic privacy is reflected in the current Part E of the Building Regulations which, for the first time, considers sound reduction within dwellings as well as between them.
Of course, ADB applies to England and Wales only, so what is happening elsewhere in the UK? Scotland’s latest Domestic Technical Handbook is similar to ADB, calling for a Category LD3 system with just smoke alarms in halls and landings – but no heat alarms at all. In complete contrast, Northern Ireland takes an exemplary approach with the current Technical Booklet E referring extensively to BS 5839-6, so that compliance with the Code meets the statutory requirements. Worryingly, the latest government fire statistics (for 2005 and published after the BD 2538 research) show a direct correlation between fire deaths and regulatory approach, highlighting significant differences in fire fatality rates between countries in the UK. This rate increased over the previous year from 7.3 to 7.7 per million population in England, and from 8.8 to 10.5 per million in Wales (both where ADB applies) while Scotland, with the lowest standard, had the highest rate of all at 12.8 per million, although still an improvement over 2004. In contrast, Northern Ireland saw an impressive fall from 8.2 to 4.6 per million, by far the lowest death rate, suggesting that the consistent application of BS 5839-6 really does save lives.
A small price to pay
Looking at the justification behind the BD 2538 report, it is questionable whether the computer modelling used reflects the real impact that modern construction and doorsets have on sound reduction – and also the time needed for smoke to transfer through these highly engineered assemblies to trigger corridor-located smoke alarms. The report used statistics up to 2002 and could not take into account the latest figures that highlight national differences and also the slowdown in the rate of reduction in domestic fire deaths – there was actually a slight increase in fatalities during 2005 to 376 – signalling that more needs to be done. The report does stress that having just one or two working smoke alarms in a home rather than none, is the most effective way of saving lives, and few could disagree with that. But to reject further improvements to make our homes safer is folly. The report establishes the discounted costs for additional 10-year warranty units installed during construction to be GB pound 29 for a smoke alarm and GB pound 39 for a heat alarm – surely such sums on the total cost of a home are a small price to pay for saving lives? There is still time for fire safety professionals to press the government for these important changes to be included in the next iteration of Part B and, in any case, to implement BS 5839-6 as a minimum standard.
While smoke alarms have been credited for bringing down fire deaths in the home, standards and regulations do not always offer uniform guidance. Gerald Jones argues for more consistency.
Most fire deaths and injuries occur in the home and there is no
doubt that working smoke and heat alarms play a major role in saving lives. But there is fundamental disagreement among those who set minimum standards and regulations around the UK about just how many are needed and where best to locate them – both to detect fire and to alert occupants. Worryingly, the different approaches taken seem to be reflected in the latest fire death statistics.
BS 5839-6: 2004 is the current Code of Practice for domestic fire alarm systems, and is well-recognised as the authoritative guidance source for both new and existing dwellings. It points out that Category LD3 – smoke alarms just in corridors – is only intended to protect circulation areas used as escape routes and "might not therefore prevent the death or serious injury of occupants in the room where the fire originates". Just over half of all domestic fire fatalities occur in the room of fire origination – in the case of bedrooms this rises to 63%. It also stresses that "the time available for evacuation of other areas once the fire is detected in the circulation area might be quite short." It is for these reasons that it recommends category LD2 for new – and many existing – dwellings as a minimum and wherever "it is intended to protect reliably any occupant in the room where a fire originates". Category LD2 requires smoke or heat alarms in living rooms and a heat alarm in every kitchen, as well as the usual smoke alarms in circulation areas.
In contrast, the current Building Regulations Approved Document B, Fire Saety – Volume 1, Dwellinghouses'(ADB), which came into effect last April, effectively requires only Category LD3, regarded by many as a deficiency which would be corrected in future. However, recently published government commissioned research looks set to frustrate these demands. The report, BD 2538 Determining the best option for the provision of additional smoke alarms in dwellings and houses, commissioned by Communities and Local Government department (CLG), sets out to resolve issues outstanding from the development of ADB. In addition to the conflicts with BS 5839-6 it also considers issues of audibility for sleeping occupants with an additional smoke alarm in the main bedroom – a sensible proposal included in the draft ADB but subsequently omitted from the final version. The report considered both issues from the perspectives of fire statistics between 1994 and 2002, computer modelling, and a cost benefit analysis. On all fronts, it concludes that adding any more smoke or heat alarms to the minimum ADB requirement would not "lead to any discernable further reductions in risk", signalling the probability of no change to the next ADB. Many would fundamentally disagree with this conclusion and the resulting misapplication of Category LD3, which relies on assumed defects in, for example, room doors to allow both sound and smoke to pass through.
New methods
But house building today is moving towards modern methods of construction using engineered, high performance components – with government encouragement. While doors may have been considered the weak link in sound reduction, for example, modern, factory-assembled doorsets now consistently provide impressive performance levels: a reduction of 36 decibels (expressed as Rw=36dB) is easily achievable without special measures. In essence, this is achieved by minimising the passage of air (and also smoke) through the doorset. Also, fire-rated doors – needed for rooms off the stairway of three or more storey houses – provide good acoustic insulation by their very nature. Yet BS 5839-6 recommends achieving a sound level of 75 dB(A) at the bedhead and also recommends more than 85 dB(A) at the doorway of each bedroom where doors exceed 20 dB "unless there is a sounder in the bedroom". As domestic smoke alarms usually generate 85 dB(A), neither of these levels can be achieved in most situations and a bedroom alarm or sounder is justified. In particular, research has shown that young children can sleep through loud alarms, while elderly people and others with hearing impairments may also not respond.
In response to this issue, the ADB consultation draft included a new provision that ‘in order to improve audibility, a smoke alarm should also be fitted in the main (largest) bedroom’ – effectively as a sounder. The same effect can be achieved with some systems using a CO alarm to help protect against carbon monoxide poisoning, while also acting as a sounder to other interconnected smoke/heat alarms. Although again omitted in the final version, this was an important proposal, recognising growing the conflict between greater acoustic privacy and the resulting sound attenuation capabilities of modern partitions and internal doors. This trend for acoustic privacy is reflected in the current Part E of the Building Regulations which, for the first time, considers sound reduction within dwellings as well as between them.
Of course, ADB applies to England and Wales only, so what is happening elsewhere in the UK? Scotland’s latest Domestic Technical Handbook is similar to ADB, calling for a Category LD3 system with just smoke alarms in halls and landings – but no heat alarms at all. In complete contrast, Northern Ireland takes an exemplary approach with the current Technical Booklet E referring extensively to BS 5839-6, so that compliance with the Code meets the statutory requirements. Worryingly, the latest government fire statistics (for 2005 and published after the BD 2538 research) show a direct correlation between fire deaths and regulatory approach, highlighting significant differences in fire fatality rates between countries in the UK. This rate increased over the previous year from 7.3 to 7.7 per million population in England, and from 8.8 to 10.5 per million in Wales (both where ADB applies) while Scotland, with the lowest standard, had the highest rate of all at 12.8 per million, although still an improvement over 2004. In contrast, Northern Ireland saw an impressive fall from 8.2 to 4.6 per million, by far the lowest death rate, suggesting that the consistent application of BS 5839-6 really does save lives.
A small price to pay
Looking at the justification behind the BD 2538 report, it is questionable whether the computer modelling used reflects the real impact that modern construction and doorsets have on sound reduction – and also the time needed for smoke to transfer through these highly engineered assemblies to trigger corridor-located smoke alarms. The report used statistics up to 2002 and could not take into account the latest figures that highlight national differences and also the slowdown in the rate of reduction in domestic fire deaths – there was actually a slight increase in fatalities during 2005 to 376 – signalling that more needs to be done. The report does stress that having just one or two working smoke alarms in a home rather than none, is the most effective way of saving lives, and few could disagree with that. But to reject further improvements to make our homes safer is folly. The report establishes the discounted costs for additional 10-year warranty units installed during construction to be £29 for a smoke alarm and £39 for a heat alarm – surely such sums on the total cost of a home are a small price to pay for saving lives? There is still time for fire safety professionals to press the government for these important changes to be included in the next iteration of Part B and, in any case, to implement BS 5839-6 as a minimum standard.
