User Manual

Siemens Switzerland Ltd

Building Technologies Division

1.4. Causes and challenges

The COST Action C17 report: “Built Heritage: Fire Loss to Historic Buildings – The Challenge before Us” by Ingval

Maxwell [1] identifies the main causes of fire in historical buildings and the associated challenges that need to be

addressed.

1.4.1. Typical causes

The most common causes of fires in historical buildings are as follows:

· Electrical faults

Electrical installations in historical buildings generally do not comply with current safety standards and

are an inherent danger in themselves. However, a number of high-profile fires have been caused by

negligence in the use of electrical equipment:

o Spotlight too close to inflammable materials such as curtains (reputed to have been the cause of the

Windsor Castle fire)

o Hot-plates, toasters and coffee makers in staff kitchenettes left switched on

o Light bulbs used with too high a rating for the corresponding fitting

o Hanging clothing on wall-mounted light fittings

o Electrical equipment unnecessarily left switched on outside opening hours

· Hot works (such as welding, soldering, brazing, cutting etc.) employed during building renovation work

· Open fires and defective flues (a common cause of fire in thatched cottages; although not strictly

included in the scope of this document)

· Smoking materials and candles

· Heating equipment

· Arson

· Lightening

1.4.2. Common challenges

The traditional construction techniques commonly used in historical buildings present a number of additional

factors which contribute dramatically to the spread of fire and to the extent of the consequential fire damage.

These include:

· Open and ill-fitting doors

· Thin wall construction

· Structural discontinuities

· Unknown wall and floor voids

· Open staircases

· Unstopped ventilation and service routes

· Undivided roof voids

· General lack of compartmentalization

1.4.3. Addressing these challenges

To adequately address these challenges we need to achieve a balance between the mindset of the conservationist

(to preserve the authenticity of the building) and that of the fire safety engineer (to provide maximum protection

for people and property). The guiding principle generally proposed by heritage protection organizations is that of

minimal intervention. This implies that any modifications to the building, whether intended to improve

compartmentalization, fire detection or the extinguishing infrastructure, should cause as little impact to the fabric

of the building as possible.