The LWF Blog

The case for residential sprinkler installation in the UK – Part Two

July 17, 2014 8:58 am

The first part of this two part blog looked at fire safety in terms of the practicalities of installing and maintaining a sprinkler system in a residential building. In this issue, we consider the benefits of a sprinkler installation in a suitable residential building.

Reduced risk to life safety from fire with residential sprinkler systems

It is true that there is still little relevant UK based data to support the use of sprinkler systems in residential premises, as such installations are far from commonplace. The US use of residential sprinklers has been much greater and, as such, has provided us with a great deal of positive performance related data on which to base our decisions.

An excerpt from the U.S. Fire Administration  ‘Home Fire Protection’ report of February 2008 gives some interesting and compelling statistics relating to fires in the US (where sprinkler installation in new build residential properties – even in one-family homes –  is now mandatory in some states).

“Fires in residences have taken a high toll of life and property. In 2006 there were

•  412,500 residential fires;
•  2,620 civilian fire deaths;
•  12,925 civilian fire injuries; and
•  over $7 billion in property damage.

Data Source: “Fire Loss in the U.S. During 2006,” NFPA

Studies by the Federal Emergency Management Agency’s (FEMA) U.S. Fire Administration (USFA) indicate that the installation of residential fire sprinkler systems could have saved thousands of lives, prevented a large percentage of those injuries, and eliminated hundreds of millions of dollars in property losses.”

In the intervening period since this report was prepared and the current time, the installation and use of residential sprinkler systems has increased in the U.S. and in the document “U.S. Experience with Sprinklers” prepared by John R Hall in June 2013 on behalf of the National Fire Protection Association, it states that “For 2007-2011 home fires, the death rate per 1,000 fires was 82% lower with wet pipe sprinklers than with no automatic extinguishing equipment.”

Sources: 

National Fire Protection Association – US Experience with sprinklers (pdf link on page)

U.S. Fire Administration – Home Fire Protection Residential Fire Sprinkler Systems Saves Lives (click small pdf link to get a copy of the report) 

Property protection with a sprinkler installation

A general misconception about sprinkler systems is that they operate throughout the building when a fire has been detected. This idea is misleading, and it should be remembered that sprinkler systems operate on a head-by-head basis. 

Residential sprinkler systems provide a number of property protection benefits; firstly, the quick reaction of the system and the rapid dousing of a fire will limit the extent of damage that the fire could have caused.

Secondly, a residential sprinkler system is designed to use less water to control or extinguish the fire than the fire brigade. A sprinkler discharges, on average, between 38 and 40 litres of water per minute. A fire-fighter’s hose could discharge up to 250-plus litres per minute at the same fire, although it is noted that modern fire-fighting techniques do not tend to use this volume of water.

Sprinklers therefore reduce not only the extent of damage caused by the fire, but also the amount of water needed to extinguish it, thus reducing overall water damage to the property following the fire. This can only have benefits for property protection and subsequent re-occupation of the space.

UK legislation and codes of practice relating to residential sprinklers

The first mention of residential sprinklers in UK legislation was in the 2000 draft document 251: Sprinkler systems for residential and domestic occupancies – Code of practice. Two years later, DD 252 was released – Components for residential sprinkler systems – Specification and test methods for residential sprinklers; a document which has to be used in conjunction with DD 251. In 2005, DD 251 was superseded by BS 9251, putting in place prescriptive requirements for the design and installation of sprinkler systems in residential premises. This code of practice is current as of July 2014, although there is work in hand.

A copy of BS 9521 can be obtained from the British Standards website shop in either pdf or physical format. However there is a cost for both and while those professionals engaged in designing buildings and installing sprinkler systems are wise to invest in a copy, interested parties may find this document provided by the Fire Sprinkler Association useful, as it provides an outline of the original guidance and provides useful insights.

Designers are increasingly considering the provision of sprinklers in residential premises. This trend has been encouraged by comments made in other legislation. BS 9999 and Approved Document B both allow for design flexibilities when sprinklers are installed in a building.

Design flexibility

The inclusion of a sprinkler system in the fire safe design of a residential building brings with it additional flexibility that may be seen as a benefit, in terms of other features. Although specifics depend upon the individual design, it may mean that some exit doors can be moved or even removed entirely, dependent upon the overall fire safety provision.

The Building Research Establishment has published a research paper on the effectiveness of sprinklers in residential premises. The experiments undertaken considered typical fire scenarios in a typical three-storey house. The tests compared the fire conditions (toxicity, visibility and heat) in the house when equipped with a residential sprinkler system, and without. The results are self-explanatory and show a high level of effectiveness when the sprinkler system is provided.

Residential sprinkler technology will certainly have an impact on the level of life safety in residential premises, and will allow architects and designers to consider additional uses, as an alternative solution to either a new design or a non-compliance issue.

The fire service

A number of fire services – Wiltshire, Merseyside, and West Yorkshire, for example – have participated in projects looking at installing sprinklers in residential premises. These systems not only have a positive impact on the safety of the building’s occupants, but also on the protection of the fire-fighters. When attending fires in premises where a residential sprinkler system has been installed, fire service personnel face a lesser risk of personal injury.

If you would like to know more about how the inclusion of sprinklers as a part of a fire safe design can assist with your residential or commercial building project, please contact Peter Gyere on 0208 668 8663 for more information or to speak to one of our Fire Engineers.

Lawrence Webster Forrest is a fire engineering and fire risk management consultancy established in 1986, with experience in the development of fire engineered technology and the application of fire safety standards including fire engineered techniques.