Incidents attended by the emergency services at suspected or confirmed cannabis farms have risen 218% in the past decade, with landlords facing millions of pounds in damages, according to a new study by Zurich UK.
The report shows fire and rescue services were called out to attend incidents at suspected or identified cannabis farms 5o times last year, slightly down on the 54 call-outs for similar incidents in 2024 and up from 17 call-outs in 2015.
Zurich compiled the report using freedom of information data obtained from 21 fire and rescue services.
Incidents have risen by 59% since 2019, highlighting the growing threat to property owners as cannabis production moves into shops, offices and other commercial units. Zurich said organised crime groups are increasingly targeting rented and vacant commercial properties.
Zurich’s Claims Investigation Unit Major Loss team investigated 17 cannabis farm-related claims since January 2022, with a combined value of £9.4m.
The insurer said investigators had found commercial units extensively altered to support cannabis growing operations, including tampering with electrical systems to meet the high energy demands of cultivation.
South Wales has emerged as the country’s cannabis farm hotspot, with its fire and rescue service called out 90 times to investigate suspected or identified farms over the past seven years. This included a peak of 25 incidents in 2020.
Meanwhile, Essex County Fire and Rescue Service also recorded 56 attendances over the past decade, followed by Hereford and Worcester Fire and Rescue Service with 55.
Home Office analysis has also identified 640 cannabis farm fires across the UK between 2019 and 2024.
Scott Clayton, head of claims fraud for Zurich UK, said: “Many landlords still picture cannabis farms operating in remote industrial estates or hidden warehouses. What we’re increasingly seeing is organised criminal groups targeting empty shops, offices and retail premises, often hiding in plain sight on high streets across the UK.
“These operations can involve sophisticated attempts to present a legitimate business front, making it difficult for landlords to spot the warning signs until significant damage has already been done.
“Robust due diligence, regular inspections and a willingness to question unusual behaviour remain some of the most effective ways landlords can protect themselves from a growing and costly threat.”
Stewart Powell, regional major loss lead for Zurich UK, added: “For many landlords the full impact only becomes apparent once a cannabis farm has been uncovered and the extent of the damage becomes clear.
“Fire risk is often only one part of a much larger problem. We’ve seen claims involving dangerous electrical alterations, extensive water damage from irrigation systems, widespread damp and mould, and significant structural changes made to conceal growing operations.
“By the time a property is recovered, landlords can be left facing months of disruption, substantial reinstatement work and repair bills running into hundreds of thousands of pounds before a building can be safely occupied again.”