Two years ago, Hoare Lea Fire Engineering produced an article 1 looking at how we could revitalise the interior layout of residential apartments, writes Gary Daniels. The article focused on the benefits that a residential sprinkler system and enhanced fire-alarm and smoke-detection systems could bring in 'opening up' flats.
It was our view, based on the design principles used in the US, that residential sprinklers and smoke detection negate the necessity for a stifling entrance hall and permit the provision of an airy open-plan living space, with bedrooms located off this central area. This obviously has fundamental benefits, in terms of space planning as well as desirability, for both occupant and developer.
To the casual observer it may appear that little has happened in the intervening period - but appearances can be deceptive. Since July 2003, the time of writing the previous article, neither Approved Document B (AD-B) nor BS 5588 Part 1, the guidance documents to which people generally refer when designing residential buildings, 2,3 have changed. However, this is not unexpected, as guidance documents are generally reactive rather than proactive, and therefore alter only after something has become the accepted norm. More interesting are the developments on the fringes of the guides.
In February 2004, the BRE released its research (BRE 204505 Effectiveness of Sprinklers in Residential Premises 4) into the provision of residential sprinklers. This research, which was sponsored by the ODPM, looked at the suitability of providing sprinklers in all types of residential accommodation.
The report is divided into two parts. The first is a desktop study reviewing the statistical risk of fire here and in other countries, as well as the potential impact of providing sprinklers in terms of both their monetary and life-saving benefits.
The second part of the study consists of a number of fire tests to assess the effectiveness of residential sprinklers in real fire scenarios.
The report is almost 800 pages long, and the following conclusions offer a glimpse of the research:
? For the majority of scenarios studied experimentally, the addition of residential sprinkler protection proved effective in potentially reducing casualties in the room of fire origin and connecting spaces.
? Sprinkler protection was found not to be a complete panacea: shielded and slow-growing fi res were still a problem.
? Smoke alarms fitted in the room of fire origin typically responded in about half the time required by the sprinklers, and well before the conditions had become life threatening.
? In order to be cost-effective in a broader range of dwellings, the installation costs and maintenance must be minimal and/or trade-offs may be provided to reduce costs by indirect means.
The conclusions of the BRE report support the fireengineering principles that a combination of sprinklers and smoke detectors will save lives. This could be considered as a trade-off against other restrictive or costly design requirements.
Hoare Lea Fire has already used sprinklers to do exactly this in the Vicus apartments in Manchester. The apartments are accessed by an elegant covered courtyard space, and Broadway Malyan Architects wanted extensive glazing from the living room in order to maximise the views of it.
Manchester Building Control agreed with our proposals that the provision of sprinklers in the living room minimised the risk of fire development and provided a suitable trade-off against fi reresisting glazing. This presented a substantial cost saving to the project and also prevents any impact on the proposed framing system to the glass.
What does this mean to us as designers? Studies have shown that where residential sprinklers are installed, the number of fire deaths in residential accommodation decreases. However, it has previously been impossible to identify the exact impact in the apartments when these systems are provided.
The BRE research now enables designers to appreciate the exact impact on factors such as temperature, production of toxic gas and visibility, where active life-safety systems, such as enhanced smoke detection and sprinklers, are provided.
Unfortunately, simply providing sprinklers and smoke detection does not give architects carte blanche to design whatever they feel like.
Sprinklers and smoke detection are definitely not panaceas that permit any design for any building under any circumstances.
What they do, though, is to enable designers to work hand-in-hand with fire engineers to maximise their architectural vision without impacting on life safety.
With sweeping changes in fire legislation imminent - in the form of the introduction of the Fire Safety Regulatory Reform Order, which will coordinate the multitude of UK and European fire safety legislation, as well as a proposed new version of AD-B - it will be interesting to see how much of the residential sprinkler research is adopted in the new documents. We will have to wait and see.
Gary Daniels is a senior fire engineer at Hoare Lea Fire Engineering