An insurer has cautioned that landlords whose properties are transformed into cannabis farms may incur repair bills amounting to hundreds of thousands of pounds. Zurich UK has examined 17 claims related to cannabis farms, with a combined value of £9.4 million, since January 2022.
The damage identified has included hazardous electrical modifications, water damage from irrigation systems, widespread damp and mould, and structural alterations made to conceal growing operations. Properties can also be rendered unusable for months while extensive reinstatement work is carried out.
Stewart Powell, Zurich UK's regional major loss lead, stated that the full impact often becomes clear only after a cannabis farm is uncovered. He noted that while the fire risk is known, it is frequently only one aspect of a larger issue.
Zurich also reports that organised criminal groups are increasingly targeting empty commercial units, sometimes presenting what appears to be a legitimate business. Fire and rescue service attendances at suspected or identified cannabis farms increased to a record 54 in 2024, from 17 in 2015. There were a further 50 attendances in 2025, based on information from 21 fire and rescue services.
Scott Clayton, the insurer’s head of claims, advised landlords to conduct robust due diligence, perform regular inspections, and question unusual behaviour to protect themselves from this threat.