Data reveals areas with most hot work fires in the UK – 2020/21

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Fires caused by hot work accounted for 16% of all fires in buildings under construction in the last year, our findings have revealed.

Despite the downturn in construction due to the Covid-19 pandemic, the industry saw 309 fires take place in buildings undergoing renovations in the UK, 52 of which were caused by hot work.

We conducted an investigation to find out how many fires there had been in buildings in construction, how many were caused by hot work, and how locations in the UK ranked.

Freedom of Information: UK Fire and Rescue Services


We contacted the UK’s 45 fire and rescue services with Freedom of Information requests for data involving fires in buildings under construction. Thirty-eight responded with recorded construction fire figures, with the rest either not holding the relevant information or having no such fires recorded.

Our findings revealed that London, Merseyside and Scotland were the regions with most fires in buildings under construction. In London, 84 fires happened in the last year, and in Merseyside and Scotland there were 19 in each.

UK Hostpots for Hot Work Fire Infographic


Top 10 regions with most fires in buildings under construction between September 2020 – September 2021


1) London: 84
2) Scotland: 19
3) Merseyside: 19
4) West Midlands: 16
5) Lancashire: 14
6) West Yorkshire: 13
7) Hampshire and Isle of Wight: 13
8) Humberside: 13
9) Greater Manchester: 10
10) South Yorkshire: 10
=10) Derbyshire: 10


Places with most fires caused by hot work in UK


Fires caused by hot work


The statistics for fires caused by hot work saw the rankings change slightly. London still remained at the top, with five of the 84 fires being caused by hot work, and Derbyshire also had five hot work fires, despite only having 10 construction fires in total.

Top 10 regions with most fires caused by hot work in buildings under construction between September 2020 – September 2021

1) London: 5
2) Derbyshire: 5
3) South Yorkshire: 4
4) West Midlands: 4
5) Scotland: 4
6) Devon & Somerset: 3
7) South Wales: 3
8) Cheshire: 3
9) East Sussex: 2
10) Hampshire: 2
=10) Cleveland: 2
=10) West Yorkshire: 2
=10) Merseyside: 2


Hot work fires in Northern Ireland

Northern Ireland do not hold the relevant information to pass on to us.

Type of hot work causing fires

While we did not receive much data about the details of the incidents, the records show that the cause of the fires were largely incidents involving blow torches, cutting and welding equipment or other equipment.

Some injuries were recorded, and most hot work fires took place in domestic buildings where renovation work was happening.

Most common causes of hot work fires

Hot work fire numbers are relatively low but not uncommon, as our findings for the previous two years demonstrate.

Because the nature of hot work in the building sector – the application of heat, flames, sparks, high temperatures and electricals – special attention must be paid to equipment and working practices. Negligence is often the main factor when a hot work fire ignites, from being either unprepared or failing to get the right training. Hot work permit and hot work passports training courses outline exactly what kind of preparation is vital before undertaking such high-risk construction duties.

Most fire are preventable.  Those responsible for workplaces and other buildings to which the public have access can avoid them by taking responsiblity for and adopting the right behaviours and procedures


The data we gathered shows that there are still times when this vigilance goes amiss in the construction industry, and at huge cost.

The cost of hot work fires

In 2020, insurance expert Zurich revealed that it had recently handled a claim that saw losses of almost £20 million due to a hot work fire. The loss team at the firm collected evidence of the case and found that major failings had taken place with the management and implementation of the project.

Losses from fires involving hot work can sometimes run into millions of pounds.  Indeed, in once recent claim, the loss was estimated at nearly £20m


Zurich also calculated that over the course of a decade, hot work fires resulted in total losses of about £69.8 million in the UK.

Recent notable fires at constructions sites have been the fire at Real Madrid Football Club’s stadium, which caught alight during welding work. The iconic music venue Koko in London in 2020 saw 60 firefighters tackle a blaze at the building, which was undergoing renovations.

Perhaps the most famous building to burn while construction work was underway is Paris’s Notre Dame, which dramatically caught fire in 2019 and is still being rebuilt today. Some reports suggest the rebuilding cost could be upwards of $1 billion.

Hot work fire numbers compared to the previous year

We requested data on hot work fires from fire and rescue services dating from September 2020 to September 2021. In our report from a previous year, 2018 to 2019, the numbers are significantly reduced. Overall construction fires were higher, however.

While there is a chance that reporting has altered over during that time, there is perhaps another reason why construction fires were lower: Covid-19.

The pandemic effect on fire statistics

In the year 2018/2019, 204 hot work fires took place in buildings under construction. Last year there were only 52.

According to the ONS:  Construction output in September 2021 was 1.0% (£141 million) lower than in February 2020 (befor the Covid-19 pandemic).  New work was 3.5% (£334 million) below February 2020 level.  Repair and maintenance work was 3.9% (£194 million) above the February 2020 level.


While the construction industry remained a vital and central part of the UK economy during the pandemic, there is no doubt that it was heavily impacted. In a survey by compliance specialist CHAS, 900 construction business owners were questioned about the impact on their work during the pandemic. When asked whether they had faced any cancellations or postponement to their work, 80.51% said yes.

In the following chart from Statista, it is clear to see the drop in construction output in England, Scotland and Wales during 2020, which only climbs back to lower levels by August 2020 – January 2021.

Percentage change over the years of overall construction output in England, Scotland and Wales from 2011-2021. Image by Statista.

Percentage change over the years of overall construction output in England, Scotland and Wales from 2011-2021. Image by Statista.

How to avoid a hot work fire

Read our guide here to find out more about reducing the risk of hot work fires in the construction industry.