Use of Automatic Fire Sprinklers in Domestic Environments

Dramatic decline in fire deaths since UK regulated sprinklers in highrises:

This paper presents a perspective on domestic fire safety from one Member State (MS) that has a long history of activities related to fire safety and especially fire safety in the home. The United Kingdom has seen a progressive decline in fire deaths, as shown in the figure below, over many decades. This progressive reduction in domestic loss is not haphazard and results from both regulation and education.

By: Dennis Davis CTIF Special Projects Adviser

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The broad conclusion of this UK experience is that sprinklers in domestic dwelling settings are reliable and effective and can offer a benefit that is economically viable. It is also feasible at an economical cost to fit them within existing housing stock. The option to use this form of active fire suppression system is therefore worthy of consideration alongside all other fire safety options and in circumstances where human vulnerability is high offers a significant advantage to life safety.

Past examples have included regulation of non-flammable children’s nightwear and open fire fireguards; education on home fire safety and domestic smoke detectors to alert residents; regulation of foam-filled furniture and of hard-wired smoke detectors in new buildings; regulation of reduced propensity ignition cigarettes; and in Scotland regulating for sprinklers into care establishments and in Wales domestic sprinklers in new buildings. Ongoing is education about domestic sprinklers in high rise dwellings and other buildings, hopefully in advance of regulation.

However this reduction has tended to stagnate not because of lack of endeavour, investment, campaigns or programmes mounted by fire and rescue authorities (FRA) but rather because it reached a natural plateau - what is sometimes referred to as the “hard to reach”. The evidence is that the more vulnerable members of society: the elderly (over 65), the very young (under 5), the disabled and those affected by substance abuse – alcohol and drugs - primarily form this group who, despite an over 80% ownership of domestic smoke warning detectors, remain unable to respond to a warning.

One solution receiving prominence in the UK because of these features is automatic fire sprinklers. Successfully used for the protection of industrial and commercial property for well over 130 years and often used to gain flexibility in building design, fire sprinkler protection is certainly not a new innovation. The transition and growing appreciation of the potential to save lives in other types of buildings – particularly domestic dwellings where the majority of deaths and injuries from fire occur – is however gaining strength. This paper explores some of the discussion and learning that may assist other MS and FRA.

Life Safety Benefits of Domestic Sprinklers

In 2004i the UK government published an appraisal of the use of domestic sprinklers. The report was non-definitive on the cost-benefit analysis and controversial partly because it assumed inflated maintenance costs. The UK Chief Fire Officers’ Association commissioned the same researchers to repeat the cost-benefit analysis, using more realistic maintenance costs. Their report, published in 2012ii, found an economic case for fitting sprinklers in new apartments and care homes, although not in houses. Meanwhile the industry response to the 2004 study was to suggest alternative conclusions, for example, promoting sprinklers as offering a level of life safety protection unobtainable by any other currently available means of fire protection and without the problem of false alarms; the existence of standards allowing uniform installation practice and the fact sprinklers were an addition not a replacement for fire detection.

Technical argument was also made to reduce sprinkler operating temperatures and explore the growing statistical evidence.

The absence of actual UK experience in the use of sprinklers made it difficult at the time to present an alternative compelling view but US studies [National Fire Protection Association] indicated distinct advantages in reductions in death and injuries from fire; reduction in risk to firefighters; greater protection of property and heritage; reduction in the impact of arson and effect on the environment; and reduced disruption to communities and business. UK proponents foresaw equal or better performance fire death rate reduction with anecdotal evidence indicating only one death recorded in a sprinklered building (a sprinkler in a care home when an occupant set fire to bedding).

Moving Forward

With this background the scene was set for what has become a transition in awareness and practice. UK national fire statistics had indicated in 2010 to 2011, 388 people died and 7400 were injured (in fires) in Great Britainiii with the domestic fire death rate almost three times as high for people over the age of 50 highlighting the growing demographic of age, with significant increases in the over 65’s, similar to many MS.

Fires and loss of life in high rise buildings, a care home in Scotlandiv and domestic dwellings in Walesv had in the interim period seen devolved UK nations require sprinklers: in new housing in Wales; Apartments higher than 18m in Scotland and 30m in England; care homes in Scotland and Wales (with sprinklers an option to door closers in England); and the Scottish government consulting on a proposal to require sprinklers in new apartments and all new social housing.

This change in the acceptance environment reflects other changes to the wider built environment including incentivisation of sprinklers in building design though flexibility in other fire control and safety measures like: avoiding a second staircase in a four-storey house; permitting an open-plan ground floor in a three-storey house; better open-plan apartments; longer escape routes, reduced fire resistance, and catering for longer fire brigade access times – in effect sprinklers were offering more freedom in design and encouraging innovative, inclusive and sustainable architecture.

Domestic sprinklers use typically 40 litres per min of water to control a fire and operate at 0.5 bar. This and the fact domestic sprinklers are small, neat and can be concealed above the ceiling removes major cost and aesthetic concerns. UK experience identifies the approximate cost of installing a domestic sprinkler in a new build 3-bedroom house is €1,700 while the additional cost of installing a 32mm rather than a 25mm mains water connection is approximately €30, the total equating typically to less than 2% of new build cost, and meeting standardsvi.

The Existing Building Legacy

Despite the growing adoption of sprinklers and their call to be more widely used, especially in high-rise social housing after a tragic fire in Londonvii, there remained reluctance due in part to the 2004 government-funded cost-benefit analysis. As stated above, in the absence of UK performance data for sprinklers, studies used NFPA data. The UK National Fire Chiefs Council therefore determined, with support of the National Fire Sprinkler Network, to conduct further research and report the findings. This was seen as an essential task in a built environment were legacy buildings are the predominant housing stock and retrofitting any apparatus is often highly disruptive for tenants and far more expensive than if undertaken in new build installations.

Reliability and Effectiveness

The report viii from the jointly-commissioned study assessed the reliability and effectiveness of sprinkler systems using UK FRS incident reports and was based on data from 2011-2015, covering 2,294 fires in sprinklered premises, of which 414 were in dwellings. Reliability was assessed as 94% and effectiveness when operated at 99%. In dwellings the fire damage area reduced from 18-21m2 to 4m2 and only one sprinkler operated in 75% of fires.

Assessed against two key criteria:

Performance effectiveness - When sprinklers operate how effective are they in extinguishing or controlling fires and thus preventing damage?

and

Operational reliability - How reliable are sprinklers in coming into operation when a fire breaks out?

The researcher concluded consistent findings when compared with other major research studies, such as, 96.2% reliable (USA. NFPA 1970), 86.1% reliable (USA. Kelly 2003), 99.5% reliable (Aus./NZ. Marryat, Rev 1988), 95% reliable (UK, Smith 1983), and 92% reliable and 96% effective (USA, Ahrens 2017). They also noted European reports of 98% and 97% performance – (product of reliability and effectiveness) – (Denmark, DBI, 2003 and 2008), 97% performance (France, CNPP, 2012) and 97.9% performance (Germany, Munich Re, 2006)

The researchers stated this provided a performance of effectiveness of 99% of the situations where sprinklers operated; and an operational reliability of the systems of 94% across all building types where sprinklers could have been expected to have operated. They added that the sprinkler confined fire in the room of origin 87% of the time; in 95% of fires less than five heads operated and in 65% only one head operated. In dwellings one head was found to operate on 75% of occasions and in apartment fires sprinklers are nearly 100% effective.

Retrofitting Domestic Sprinklers

In addition to this statistical analysis practical activities have included retrofitting sprinklers. Two case studies are cited that have demonstrated the practicality of retrofitting sprinklers and shown that costs are reasonable. In the light of the recent tragic loss of life in the 2017 London Tower Fireix, retrofitting is desirable and the installation of domestic sprinklers in over 1,000 publicly-owned residential towers is now being actively pursued.

Case 1x involved a 13-storey tower of 47 apartments used as social housing where the occupiers remained in situ during work and the cost was €1,300 per apartment, judged comparable to other fire protection costs. Case 2xi involves a municipal administrative area having 52 buildings higher than over five storeys where two eight-storey buildings housing 63 apartments have been completed, and four 15-storey towers where work has commenced. The estimate is 1 day of work per flat with the 63 apartments costing €110,000 and the whole programme estimated to last 3-5 years.

Case 1

The block, which fully complied with current UK fire safety standards, is one of six 13-storey towers built during 1962. It had recently undergone major refurbishment work under the UK government’s Decent Homes Scheme and was fitted with a fire detection and alarm system. The refurbishment had not, however, included consideration of the value of sprinkler protection. The tower originally contained 48 flats designated as ‘sheltered housing’, where vulnerable elder people with a daytime warden reside. The ground floor contains offices and communal rooms, with the 46 one-bedroom flats and 1 two-bedroom flat on the remaining 12 floors.

Importantly it was agreed that the 47 residents of the flats would remain in occupation during the installation work because the project’s steering group considered if a system could be retrofitted in an occupied block, this would demonstrate the practicability of sprinkler retrofit. The findings of the pilot project provide evidence of the practicality and cost effectiveness of installing sprinklers in older high-rise blocks. In addition, the project has created a template and methodology for the design of sprinkler systems in other un-protected high-rise blocks elsewhere in the UK.

Case 2

This involved a FRA Community Sprinkler Project aiming to fit sprinklers into all buildings higher than five floors across their area, including retrofitting in existing buildings and installation in all new builds. The project involved fire engineers working with housing providers and local fire safety officers working locally in support of the ongoing project, with some funding made been made available to support the installation of systems coming directly from the FRA budget. In July last year two concrete-built blocks containing 63 one- and two-bedroom flats for over 55's were retrofitted in these extremely challenging circumstances. Each flat took on average a day to complete.

Conclusions

The broad conclusion of this UK experience is that sprinklers in domestic dwelling settings are reliable and effective and can offer a benefit that is economically viable. It is also feasible at an economical cost to fit them within existing housing stock. The option to use this form of active fire suppression system is therefore worthy of consideration alongside all other fire safety options and in circumstances where human vulnerability is high offers a significant advantage to life safety.

Cover Photo: Fire sprinkler mounted on a roof, Photo by Wikipedia

Author: Dennis Davis CTIF Special Projects Adviser

i Building Research Establishment Report Effectiveness of Sprinklers in Residential Premises [Feb 2004]

ii Cost Benefit Analysis of residential sprinklers, BRE report 264227 [Mar 2012]

iii www.gov.uk/government/collections/fire-statistics

iv Rosepark Care Home [January 2004] www.gov.scot/resource/doc/175356/0119308.pdf

v Building Research Establishment Report Cost Benefit Analysis of Residential Sprinklers [2012]

vi Sprinklers should be installed to British Standard BS 9251:2014 Fire Sprinkler Systems For Domestic And Residential Occupancies -Code Of Practice and BS EN 12845:2003 for non-residential premises

vii Lakanal House [July 2009], Lambeth.gov.uk/.../lakanal-house-coroner-inquest

viii Efficiency and Effectiveness of Sprinkler Systems in the United Kingdom: An Analysis from Fire Service Data [May2017]Optimal Economics Edinburgh, National Fire Chiefs Council

ix Grenfell Tower Fire London [14 June 2017] www.grenfelltowerinquiry.org.uk

x British Automatic Fire Sprinkler Association [2012], High Rise Retrofit Pilot Project – Handbank, Callow Mount, Gleadless, Sheffield

xi Staffordshire Community Sprinkler Project [2017] www.staffordshirefire.gov.uk