The latest statistics show worrying differences in domestic fire fatalities around the UK that align with varying national requirements for smoke and heat alarms in new homes. Despite this, recently published government-commissioned research looks set to frustrate demands to put right deficiencies in Building Regulations, as Gerald Jones - Kidde Fyrnetics Business Manager of Kidde Safety Europe – explains.

Research summarised in the report ‘Determining the best option for the provision of additional smoke alarms in dwellings and houses’ (BD 2538), commissioned by Communities and Local Government (CLG), sets out to resolve two issues outstanding from the development of the current ‘Approved Document B, Fire Safety – Volume 1, Dwellinghouses’ (AD B), which came into effect last April. Firstly, AD B calls only for smoke alarms in corridors (described as Category LD3) and heat alarms just in Kitchens opening onto them. This contradicts BS 5839-6:2004 requiring Category LD2 as a minimum for new homes, with smoke or heat alarms in Living Rooms and a heat alarm in every Kitchen, as well as the usual smoke alarms in circulation areas.

DEFINITIVE CODE OF PRACTICE

BS 5839-6:2004 is the current Code of Practice for domestic fire alarm systems and well-recognised as the authoritative guidance source for both new and existing dwellings. It points out that Category LD3 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 BS 5839-6:2004 recommends Category LD2 for new dwellings as a minimum and wherever “ it is intended to protect reliably any occupant in the room where a fire originates.”

The second issue addressed in the BD 2538 report concerns the ability of corridor smoke alarms to awaken sleeping occupants. The AD B 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. This can also 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 omitted in the final version of AD B, this was an important proposal, recognising growing pressures for 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 considers sound reduction within dwellings as well as between them.

CLOSING THE GAP

Although doors are considered the weak link in sound reduction, modern, factory assembled doorsets now consistently provide impressive performance levels: 36 Rw dB is easily achievable without special measures. This is largely due to sealing up of door edges to minimize air – and smoke – flow. BS 5839-6: 2004 recommends achieving a sound level of 75 dB(A) at the bedhead.  It 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. It is therefore questionable whether the computer modelling used in the BD 2538 report reflects the real impact that modern doorsets have on sound reduction – and also the time needed for smoke to transfer from source of fire rooms through these highly engineered assemblies to trigger corridor located smoke alarms.

The BD 2538 research considered both issues from the perspectives of: fire statistics between 1994 and 2002, computer modelling and a ‘cost benefit’ analysis. On all fronts, it concluded that adding any more smoke or heat alarms to the minimum AD B requirement would not “lead to any discernable further reductions in risk”, signalling the probability of no change to the next AD B. Many would fundamentally disagree with this conclusion and the resulting misapplication of Category LD3, relying on assumed defects in modern doorsets which, increasingly, are simply not there. The BD 2538 report and AD B only apply to England and Wales. Scotland’s latest Domestic Technical Handbook is similar to AD B, calling for a Category LD3 system with just smoke alarms in halls and landings – and even more worryingly, no heat alarms at all. In complete contrast, both Northern Ireland and Eire take an exemplary approach with Regulations referring extensively to BS 5839-6: 2004.

REGULATIONS SAVE LIVES

So, who is right? The latest UK fire statistics (for 2005 and published after the BD 2538 research) highlight significant national differences in fire fatality rates (per million population). This rate increased over the previous year from 7.3 to 7.7 in England and from 8.8 to 10.5 in Wales, while Scotland maintained the highest rate of all at 12.8, although an improvement over 2004. In contrast, Northern Ireland – with the most stringent smoke and heat alarm requirements - saw an impressive fall from 8.2 to 4.6, by far the lowest death rate. Clearly, adopting BS 5839-6: 2004 saves lives.

The BD 2538 report used statistics up to 2002 and could not take into account these latest figures which also highlight a 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 – rather than none – in a home 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 this is a small price to pay for saving lives? There is still time to press the government for these important changes to be included in the next iteration of Part B – and perhaps even the Scottish Technical Standards – to bring them into line with Northern Ireland. But we can all take action now and implement BS 5839-6: 2004 as a minimum.