Fire prevention is a discipline that relies in most cases on the use of building elements or standardized solutions. The verification of safety with respect to the risk of fire, therefore, normally starts from the control of parameters such as the width of the escape routes, the characteristics of fire resistance of the structures and the characteristics of the ignition behavior of the covering and furniture materials. If a project lacks one or more of these aspects, it is modified by adding or changing elements. But what to do when the building has already been built and, above all, it cannot be modified because its construction elements, its visual impact and its history do not allow it to be modified without society accepting these changes?
This question is the first that professionals in charge of evaluating fire safety must ask themselves before starting their work and it does not always have an answer that will satisfy all needs. Installing fire-fighting water systems can save a building from destruction, but in some circumstances the uncontrolled activation of these systems can cause more damage than a fire would cause. An inadequate escape route (for example, a staircase that is too steep or too narrow) can compromise the exodus of people present in a building, but what to do if building an external emergency staircase would substantially damage the appearance of that building ?
There is no magic wand to solve these problems in almost any building of historical or artistic value in the world. The level of safety to which projects are now required to comply is much higher than that of buildings of a few hundred years ago. Not surprisingly, the history of architecture and of the most important cities in many countries is marked by fires that have destroyed buildings or entire urban areas.
One of the possibilities that professionals have at their disposal to reflect with greater awareness on the risks to which historic buildings are subject is to simulate what would happen in the event of a fire, to better understand the vulnerabilities of buildings and to agree on intervention strategies (physical measures , plant engineering, management and use) that can minimize the risks. This evaluation philosophy is what characterizes the performance approach to fire safety.
Fire Safety Engineering (or Fire Protection Engineering) is the most powerful tool for assessing fire risk in heritage, historical or cultural buildings. Using the techniques developed within the performance based approach to improve the protection of cultural and historical buildings against fire, at the moment it’s the only possible way that allows to match safety needs with conservation issues. According the Wikipedia page, Fire safety Engineering is “the application of science and engineering principles to protect people, property, and their environments from the harmful and destructive effects of fire and smoke. It encompasses engineering which focuses on fire detection, suppression and mitigation and fire safety engineering which focuses on human behavior and maintaining a tenable environment for evacuation from a fire. In the United States ‘fire protection engineering’ is often used to include ‘fire safety engineering“.
The other possible way to approach the problem, the prescriptive approach, does not allow to address the extremely various problems that safety consultants have to face in protecting from fire historic artefacts. Such buildings, actually, normally are far away from any applicable standard, in the egress routes and fire behaviour of materials design. Moreover, hardly protection plants can be installed without severe interference with the historic characteristic of the building.
Currently, there aren’t many studies about the use of Fire Safety Engineering in cultural or heritage buildings protection. Are worth to be cited the Cost C 17 Action “Fire Loss to Built Heritage”, an activity funded by the European Science Foundation which ended in 2006 and the activity of the NFPA , which has published and keep updated two important standards: 909 (Code for the Protection of Cultural Resource Properties – Museums, Libraries, and Places of Worship) and 914 (Code for Fire Protection in Historic Structures).
To date, the Cost C17 remains the most successful research action aimed at improving the understanding of the fire risk to the built Heritage. The references listed by the Action can help to have an idea of the work done:
- Analysis of significant fires WP 2
- Bridge street fire exercise feedback. 10-04
- British Standards Institute November 2004, Sprinkler systems
- Building Bulletin 100, Designing and managing against the risk of fire in schools
- Building Research Establishment, Fire Suppression in Buildings using water mist, fog or similarsystems 2005 Case Studies 2005
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