New research on fire risks to high-rise blocks of flats

Following the 2017 Grenfell Tower fire in West London that killed 72 people and left 201 households homeless, and subsequent fires to tower blocks and other multi-occupancy residential buildings, the safety of high-rise living has become the subject of national and international debate.

A recurrent theme of the high-rise safety debate has been the conflicting perspectives over what advice and help should be given to residents in the event of a fire.

Prior to Grenfell, government policy and housing sector guidance in England stated that for residents in a purpose-built block of flats, it would normally be safer for those not in the immediate vicinity of a fire to ‘stay put’ in their own flat rather than evacuate during a fire. This advice rested on the assumption that both the individual dwellings and the common parts of such buildings, including the means of escape, would have adequate fire-resisting construction - known as compartmentation - as required by building regulations dating back to at least the early 1960s.

However, as Phase 1 of the ongoing Grenfell Tower Public Inquiry has conclusively demonstrated, the fire at Grenfell Tower did not behave as expected due to catastrophic failures in the building’s ability to resist the spread of fire and toxic smoke. These compartmentation failures, primarily caused by the Tower’s unsafe refurbishment between 2014 and 2016, allowed a small kitchen fire to break out of a window on the fourth floor and rapidly climb up the 24-storey building’s east face before consuming most of the building within hours.

Tragically, the Public Inquiry has also found that a major factor in the unprecedented death toll was the faith-like belief in compartmentation held by the London Fire Brigade (LFB) and those responsible for managing the fire risks to the residents such as the local authority landlord and its fire risk assessors. This meant that residents were wrongly told to stay put in the burning building instead of evacuating when they had the chance.

While the Public Inquiry’s findings to date have been widely accepted, there has nevertheless been reluctance by government and the housing sector to implement its main interim recommendation - to legally require building owners to plan complete building evacuations and create Personal Emergency Evacuation Plans (PEEPs) for residents unable to leave unaided. Opponents of PEEPs see them as impractical and unnecessary, arguing that Grenfell was an anomaly in terms of fire spread and the scale of fatalities, and that it is rare for flat fires to kill, affect other flats, or necessitate evacuation. In other words, high-rise is not high-risk, and the ‘stay put’ principle remains safe.

The debate over stay put or evacuation - and whether or not PEEPs should be mandatory in high-rise flats - is fundamentally about whether, in the event of a fire, high-rise buildings are safe enough for those not in the vicinity of the fire to remain in their flat whilst attending Fire and Rescue Services (FRS) tackle the fire. This judgement call rests on having confidence in the effectiveness of compartmentation, the means of escape, and firefighting infrastructure in an individual building when contemplating the much longer intervention times for FRS to blocks of flats compared to other types of dwelling. It involves assessing the fire risk to people, combining the likelihood of a fire occurring and the consequences to the safety of people from that fire.

Post-Grenfell revelations about the scale of combustible cladding and other fire safety defects on high-rise buildings, as well as evidence from previous and subsequent dangerous fires, suggest there are real risks of death and injury from a presumption in favour of the stay put approach. However, there remains no comprehensive research or evidence base about the fire safety of blocks of flats to inform this policy debate.

Using previously unpublished Home Office fire incident data for England, and supported by funding from Research England, I have been working with independent high-rise safety expert, Phil Murphy, and my University of Leeds colleague, Andy Turner, to explore the possible relationships between different dwelling types and heights, the frequency of fire incidents, the floor of fire origin, the prevalence of delays to firefighting and unusual fire spread, the need for evacuations and rescues, and the risk of serious harm.

Our overall findings from analysing dwellings fires between 2010/11 and 2019/20 suggest that there are increased fire risks to people in purpose-built blocks of flats compared to other dwellings. For example, while residents of dwellings in blocks of flats appear no more likely to die or be injured than for any other dwelling type once a fire breaks out, when fire incidents are normalised by the estimated populations living in each dwelling type, flat dwellers are exposed to a much greater probability of their building experiencing a fire than those living in other dwelling types and are more than twice as likely to die and just under twice as likely to be injured in a fire.

We also found that fires in purpose-built blocks of flats are in general much more likely to experience delays to firefighting than other dwelling types, and this likelihood of delay increases dramatically for high-rise buildings due to the specific difficulties faced by firefighters at this building typology. A high-rise flat fire is over six times more likely to experience a delay to the start of firefighting than fires to houses. Delays also increase the likelihood of a fire resulting in a fatality or casualty for purpose-built blocks of flats.

These findings question the previously optimistic assumptions about the fire-resisting construction of purpose-built blocks of flats, including high-rise buildings, that underpinned government guidance on fire safety management before the Grenfell Tower fire. Therefore, the mandatory requirement for Personal Emergency Evacuation Plans (PEEPS) in high-rise residential buildings appears to be a sensible but essential precaution for those who cannot self-evacuate unaided. There is also evidence to support their wider use in buildings below 18 metres.

Download the full report below: The Fire Risks of Purpose-Built Blocks of Flats: an Exploration of Official Fire Incident Data in England.

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