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1 December, 2008
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Doors in older properties are almost exclusively timber but none will have been designed as a fire door when installed

Preserving our heritage
01/04/08
Published:  08 August, 2008

A fire in a heritage building can mean irretrievable loss

Peter Barker, head of consultancy at TRADA sister company Chiltern International Fire, discusses the particular fire safety issues posed by heritage buildings

Fire is the single greatest threat to any building. In the case of an historic building, the loss can be irretrievable. And, sadly, fires in historic buildings are not rare events. According to The Cost of History: Fire Risk Management Journal, between January 2002 and June 2006, an average of seven UK heritage buildings per month were lost or damaged as a result of fire.
Also, while it is important to preserve the nation’s finite stock of historic buildings and artefacts, the safety of occupants, staff and visitors must not be forgotten and, indeed, should take precedence when considering fire risk.
It is vital, therefore, to minimise the likelihood of fire, by early elimination of major risks, or careful management and control over risks that cannot be eliminated. If a refurbishment or change of the use of the building is planned, the fire safety strategy must be considered at the start of any design process. 
Approved Document B – Building Regulations for Fire Safety (ADB) provides practical guidance on Building Regulations requirements for England and Wales, but historic buildings have specific challenges to face and rarely do they ‘fit’ the prescriptive nature of the information given in ADB.
By dealing with each of the requirements in turn, however, and introducing practical solutions suited to the building and its contents, an holistic fire safety strategy can be developed to ensure a safer environment for occupants, reduce the risk of fire and minimise the impact of fire, should one occur.
Under the requirements of the Regulatory Reform (Fire Safety) Order, a suitable and sufficient fire risk assessment (FRA) is required for all premises other than private dwellings. For historic buildings it is of paramount importance that a well structured and properly implemented fire safety management plan accompanies the FRA.
Preventing a fire in the first place is the obvious ideal situation and is the first stage of physically assessing the risk of fire within any building. By identifying ignition sources and flammable materials and either removing them or introducing alternative methods of storage, the fire risk will be greatly reduced.
Protective measures are covered by the five sections (B1 – B5) of Part B of the Building Regulations and are put in place to protect the occupants in the event of fire. In the case of historic buildings, they also play a crucial role in property á
Ü protection and artefact retrieval. However, such measures may be disruptive to the original fabric of the building, while the physical installation of the systems can present challenges.
Room geometry within historic properties, for example, can render the British Standards’ recommendations for the use of detectors unsuitable, while large windows or ornate ceilings can allow a large flow of air over detectors, preventing them from responding quickly enough. Also, if sprinklers are chosen, careful planning for pipes and tanks is needed and, when upgrading the fire resistance of doors and walls, care needs to be taken to ensure that their authenticity and aesthetics are not irreversibly damaged.
Linings within historic buildings will vary from exposed brick to timber panelling and wall-hung fabrics, so premises have to be considered on a case-by-case basis. It is important that the building retains its original look and feel, so any enhancement of the linings that affects the appearance should only be undertaken if absolutely necessary.
To inhibit internal fire spread within the structure, it is important to work with the existing construction of the building. Fire stopping within voids adjacent to doors and between horizontal and vertical compartments can often be achieved with minimum disruption, but care must be taken to avoid damaging original panelling and any ornate features. It may also be worth taking advice from an historic building specialist as to whether the fire stopping measures will affect the airflow within the building, as this has the potential to create problems with moisture/damp in the future.
Doors are a key area for consideration. Doors in older properties are almost exclusively in timber but none will have been designed as a fire door when installed. Various methods are available for upgrading fire resistance, with varying impact on the aesthetics of the door and the original timbers used in construction. Any upgrade of a timber joinery door will mean modifying or removing some of the original timbers, perhaps by removing material to add an intumescent strip, or changing panels and items of hardware.
When planning to upgrade doors, it is important to understand the restrictions on how much of the door can be altered, because some joinery doors are as historically valuable as the artefacts and the building itself. If a door is deemed to require a fire rating, but cannot be changed in any way because of heritage restrictions, it may be possible to replace the door with a replica after commissioning an assessment in lieu of a fire test. The assessment can be used as a design appraisal of an existing doorset design, so that a fire-rated copy can be constructed.
For any upgrade, it is strongly recommended that specialist advice is sought. Consultancy is so often seen as an additional expense, when in fact the client can waste a great deal of time and money to achieve very little.
Early warning of fire is critical, especially in historic buildings where the presence of hidden voids and the materials used in construction will facilitate the fire spreading rapidly throughout the building. There may be limited options for escape routes, further increasing the need for an efficient early warning system, as it is likely the routes used for escape may not comply with the guidance set out in ADB.
By careful positioning of detectors within hidden voids, in areas that pose greater risk to occupants and in areas of special historic importance, a fire can be detected before it develops to a size where it threatens life, the building and important artefacts. First aid fire-fighting equipment (for example, extinguishers and blankets) should be available throughout and staff should be properly trained in its use.
External fire spread needs to be considered, too, both in terms of the likelihood of the historic building spreading fire to neighbouring buildings, and how easily a fire would spread to the building from elsewhere.
The risk of external fire spread is predominately applicable to those buildings with extensive combustible façades or construction materials and, because it will only be possible to work with the existing fabric of the building, remedial solutions will be limited. Surface applied treatments for timbers are available but are restrictive because they will have to be regularly reapplied.
Another solution is to install water mist suppression systems that effectively shroud the building in water mist and prevent the fire from engulfing it. These systems would be worth considering for structures such as historic timber ships and wooden churches or even one part of a building such as a thatched roof.
Once the FRA has been completed and suitable protective measures are in place, a robust management system in the form of a fire safety management plan must be drawn up, incorporating a business continuity plan, so that in the event of fire, restoration work can proceed as quickly as possible. Being prepared for an emergency will massively improve business recovery rate.

For further information visit www.trada.co.uk; www.chilternfire.co.uk; www.historic-scotland.gov.uk; and www.english-heritage.org.uk/FReD

Queen Charlotte's house at Kew


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