Home Office review of high-rise residential evacuation procedures published

Following the Grenfell Tower fire on 14 June 2017, the Independent Review of Building Regulations and Fire Safety was led by Dame Judith Hackitt and the outcomes published. This was followed by Phase 1 of the Public Inquiry into the tragic fire. The subsequent reports outlined several recommendations, including that the Government should develop national guidelines for carrying out partial or total evacuations from high-rise residential buildings.

In March 2020, the Home Office commissioned the National Centre for Social Research (ie NatCen) to produce a synthesis of existing academic evidence regarding fire evacuation in high-rise residential buildings. It’s intended that the findings of this review will contribute towards the ongoing work aimed at developing national guidance for evacuation strategies.

The review aimed to summarise the existing academic evidence on evacuations from high-rise residential buildings in the UK and assess the strength of the evidence. It also sought to identify any weaknesses and gaps in the current evidence base and answer the following key research questions:

*what are the most effective methods of evacuation from fires in high-rise residential buildings

*how do occupants make decisions about fire evacuation from high-rise residential buildings

*how do firefighters make decisions about evacuating occupants from high-rise residential buildings

The NatCen review was undertaken using a rapid evidence assessment design comprised of three key stages:

*Literature searching stage to identify the nature, availability and range of evidence relevant to the research questions

*Critical evaluation stage to evaluate the quality of evidence

*Extraction and synthesis stage to extract and summarise data thematically

During the critical evaluation stage, studies were scored using a weight of evidence tool developed by NatCen to assess relevance to the research question and quality of research. Once scored, approximately 60 studies were prioritised for full review by a panel of researchers based on the weight of evidence score and contribution to the evidence base.

Scope of the review

The Home Office is responsible for Fire and Rescue Services in England, but relevant evidence from the UK and other international evidence was included in this review. The review focused on peer-reviewed academic research published since 1985 to ensure identified UK research was published in line with the Building Regulations brought into law that year, through to July 2020 when the review took place.

Given the anticipated limited UK-specific academic evidence base, the review includes non-UK research in addition to some research relevant to non-high rise and non-residential settings.

While the international evidence promotes learning from other fire evacuation scenarios, the transferability of international and non-residential evidence must be considered, particularly in relation to differences in the design and layout of UK high-rise residential buildings and the impact this may have on fire evacuation scenarios and procedures.

This rapid evidence review does not consider operational guidance and it acknowledges that the transferability of findings from the academic research may be limited due to a range of factors such as differences in building design, building maintenance and regulations.

The review did not cover guidance from Fire and Rescue Services or any other organisation on fire evacuations from high-rise residential buildings in the UK, including the use of a ‘Stay Put’ strategy and lifts during evacuations.

It’s important to note that National Fire Chiefs Council and stakeholder-led simultaneous evacuation guidance was issued back in October 2020 and has subsequently been updated.

Key findings

Overall, the review found that there’s limited evidence focused specifically on fire evacuation in UK high-rise residential settings. The majority of available academic research is international, with only a handful of studies providing UK-based evidence.

Further, while few studies provided information to assess the transferability of findings to UK high-rise residential settings, the limited UK-specific evidence did corroborate international findings, in turn suggesting a certain degree of transferability.

However, most evidence identified in this review offers insight into different elements of evacuation strategies rather than a comprehensive assessment of evacuation strategies from high-rise residential settings.

No studies identified mention a ‘Stay Put’ strategy. While some inference can be taken from North American studies that mentioned ‘Defend in Place’ (sometimes referred to as ‘Stay-in-Place’), this is a different evacuation strategy that places different expectations on residents. The findings should also be considered with this in mind.

*What are the most effective methods of evacuation from fires in high-rise residential buildings?

The review found the availability of evidence on effective methods of fire evacuation in high-rise residential buildings is significantly limited. However, the body of evidence suggested that, when evacuation is necessary, no single strategy is universally appropriate for high-rise residential buildings. Instead, every high-rise residential building should have a fire evacuation plan individual to it and developed in full consideration of the building design, taking into account the composition of occupants and, crucially, the presence – or, indeed, absence – of effective compartmentation.

Considering the limited evidence base, the findings of this review tentatively suggest that, when evacuation is necessary and effective fire safety arrangements such as compartmentation are in place, phased and partial evacuation strategies (such as ‘Defend-in-Place’ and ‘Delayed Evacuation’) are safer than simultaneous evacuation (the studies did not consider differences in when simultaneous evacuation could take place) within high-rise residential settings.

The evidence also identified the importance of delayed evacuation for those unable to evacuate in an unassisted way and the need to ensure exit routes and refuge areas are safe and effective. The success of phased, partial and delayed evacuation strategies, however, depends on effective compartmentation and other building design features, so too good communication systems to provide occupants with sufficient and ongoing information during the procedure.

International modelling and simulation studies (no UK studies were identified) suggested the use of fire-safe lifts can reduce overall evacuation time in high-rise buildings, depending upon the number of floors and the number and composition of occupants. That said, the extent to which these findings apply to real-fire scenarios – and indeed specifically to UK high-rise residential settings – is somewhat unclear.

Most of the available evidence that addressed the effective evacuation of vulnerable groups focused on older residents and those residents with limited mobility and visual impairment.

*How do occupants make decisions about fire evacuation from high-rise residential buildings?

Due to a lack of robust evidence, a limited amount of specific evidence covers occupant decision-making during high-rise residential fires. While the study of occupant decision-making during high-rise residential fires is well established, much is based on small-scale survey and qualitative studies. Caution must therefore be taken when considering the findings, particularly if seeking to generalise to wider populations or to other high-rise residential buildings.

Collectively, UK and international evidence suggested occupants do not immediately evacuate upon recognising fire cues. Both UK and international studies also suggested the occupants of high-rise residential settings are reluctant to use lifts during fire evacuation procedures.

In a UK context, this chimes with the National Fire Chiefs Council’s ‘Stay Put’ position statement, which generally states that stairs should be used instead of lifts if occupants need to evacuate.

*How do firefighters make decisions about evacuating occupants from high-rise residential buildings?

There’s a significant lack of published academic peer-reviewed evidence on how firefighters make decisions on evacuating occupants from high-rise residential buildings in the event of a fire. Of the limited evidence available, most is international and focused on the decision-making of firefighters in general rather than specifically in high-rise residential settings.

Future research and evidence gaps

While the findings from this review provide some insight into fire evacuation in high-rise residential buildings, the ability to identify the most effective methods of evacuation is limited by a paucity of high-quality research and an evidence base largely developed in non-UK settings.

An important contribution of this review is therefore the identification of significant and wide-ranging evidence gaps, which would need to be addressed in order to improve the peer reviewed academic evidence base. These include:

*research that directly compares the effectiveness of different evacuation strategies in UK high-rise residential settings

*research on the effectiveness of lifts for fire evacuation within UK high-rise residential settings

*research on UK high-rise residents’ willingness to use lifts during fire evacuation upon instruction

*research on the effective evacuation of vulnerable groups from UK high-rise residential settings (encompassing residents with reduced cognition, those with small children and residents with English as an additional language) and also taking into account certain residents’ potentially limited knowledge of evacuation procedures (such as those who are short-term, un-tenured or guests)

*research on firefighters’ decision-making regarding the evacuation of occupants within UK high-rise residential settings