Extension cable fire establishes neighbour liability despite no actual knowledge of defect

In Smith v Logan [2025] EWCC 56, HHJ Stephen Davies found that property owners owed a duty to neighbouring properties to ensure electrical installations were properly certificated, even where a domestic extension cable had functioned without incident for over a decade.

Background

A fire on 8 May 2018 originated at 10 Vale Terrace and spread to the adjoining property at number 9. The blaze, which effectively destroyed both terraced houses, was traced to a domestic-grade extension cable installed between 2005 and 2007 by Mrs Logan's former partner. The cable ran from the kitchen through the rear garden to power a freezer in an outbuilding shed.

The claimant's insurers, AXA, sought £350,000 in agreed damages through a subrogated claim against the defendants, Mr and Mrs Logan, on grounds of negligence and nuisance.

Causation analysis

The court applied the principles from Palmer v Nightingale [2016] EWHC 2800 (TCC), requiring the claimant to prove causation on the balance of probabilities rather than merely eliminating alternative theories. Four potential causes were examined: electrical fault in the cable, carelessly discarded smoking materials, lithium battery failure, and arson.

The defendants advanced a theory that smoking materials from the claimant's daughter might have caused the fire. However, the court rejected this, finding no basis for drawing adverse inferences from the daughter's absence as a witness. The contemporaneous evidence indicated she was attempting to quit smoking, and the inherent unlikelihood of a cigarette end landing precisely under the shed in wet conditions undermined the theory.

Expert evidence established that the domestic cable lacked steel armouring necessary for external use, rendering it vulnerable to rodent damage. The judge preferred Dr Jowett's straightforward explanation of rodent-induced electrical fault over Dr Butler's more speculative smoking materials theory, noting Dr Butler had not mentioned this possibility in his initial report.

Liability principles

The court emphasised that nuisance and negligence converge where defendants knew or ought to have known that reasonably foreseeable harm could result from their conduct. Citing Clerk & Lindsell on Torts, the judge confirmed that "conduct" includes activities authorised, continued, or adopted by property owners.

Mrs Logan was found to have "authorised" the installation by permitting it and subsequently "adopted" it through continuous use. Critically, she knew Mr Davies lacked electrical qualifications yet allowed permanent power supply to the shed. Three specific occasions arose when she ought to have sought professional advice: when installing the freezer for permanent use, when an electrician repaired mouse-damaged cabling elsewhere in the property, and during kitchen rewiring works.

Mr Logan became jointly liable upon acquiring joint ownership in 2014, as he continued using the installation whilst aware of its permanent nature and improvised origin.

Regulatory context

Part P of the Building Regulations 2010 requires electrical works in dwellings to be notified or carried out by registered installers. The guidance references BS 7671:2008 (Wiring Regulations), which mandates protection against fauna damage. Whilst breach of Building Regulations is a criminal matter, the court accepted it constituted evidence of negligence.

The judgement establishes that property owners cannot rely on the absence of obvious defects or previous incidents to discharge their duty of care. Where electrical installations serve permanent purposes and lack proper certification, owners must proactively seek professional assessment, particularly when opportunities naturally arise through other electrical works. The reasonable foreseeability threshold is met when owners know installations lack professional oversight, regardless of whether they appreciate the specific mechanisms of potential harm.