Fire risk assessments for buildings of special architectural or historic interest

This paper looks at the additional factors that should be considered when a fire risk assessment is undertaken for a building of special architectural interest. The fire risk assessor should have a comprehensive understanding of fire dynamics and its effects on traditional materials and methods of construction. Recent disastrous fires such as those at the Glasgow School of Art, Clandon Park, Rio’s Museum Nacional and Paris’s Notre Dame momentarily attracted international attention for the loss of the building and contents, but there have been few constructive suggestions for improving the situation, beyond the usual panacea of fitting sprinkler systems. Risk-based legislation allows for some leeway in applying fire safety solutions, but guidance does not address property protection, which is usually left to owners, architects and contractors to think about. During the Notre Dame fire, two sections of the stone vaulted ceiling collapsed, the first due to the collapse of the tower, the second either from the weight of firefighting water or debris. This allowed ventilation beneath the fire, like a furnace, making it hot enough to vaporise the lead roof. Oxford University is currently investigating the loss of compressive strength to limestone when subjected to heat to see if this contributed to the collapse.