Jason Kallis

Jason advises on disputes involving architects, engineers, contractors, and subcontractors, including multimillion-pound design defect, delay, and subsidence claims, achieving resolution through adjudication, mediation, settlement, and strategic negotiation.

• Advised on the removal of a cladding system on a hotel housing council tenants and the recovery of that sum (£8 million).
• Advised on a Party Wall Act dispute that took place concerning the development of super prime properties in London including engaging with a Party Wall Act appointed surveyor and a subsequent appeal after referral to third party (£40 million).
• Advised on a claim by a large construction company against an architect for failing to incorporate movement joints into the design of an office block in Manchester (headquarters for national law firm) (value of claim £2 million).
• Negotiated an extension of time and settlement without payment of LADs re a claim against a piling contractor with design responsibility relating to the installation of foundations at a wind farm development as a result of poorly designed crane pads which failed load tests (value of claim £800,000).
• Settled at mediation a claim against a geotechnical engineer relating to a poorly designed flood defence where it was alleged that the defence could not withstand a full head of water, and leaked (value of claim £2 million).
• Acted in a developer’s claim issued in the Technology and Construction Court against a structural engineer for alleged poor design of steel frame leading to demolition of a large commercial building prior to practical completion (value of claim £2 million).
• Acted in an adjudication against a quantity surveyor following an allegation by a council of negligent project management which caused delay to the completion of a new school (value of claim £200,000).
• Defended a specialist plumbing subcontractor whose poor workmanship was alleged to have caused leaks throughout a large block of flats (value of claim £1 million).

Jason advises manufacturers, designers, and insurers on product liability disputes, including fire claims, defective designs, and electrical component failures, addressing liability, causation, coverage, and recovery, often involving complex multi-party proceedings.

• Acted for an international manufacturer of electrical components, defending claims against them arising out of fires caused by defective miniature circuit boards in consumer units and then pursuing recoveries from “Part P” electricians for ignoring recall notices.
• Acted for a furniture designer and their insurers for producing an allegedly “unbuildable” design. Handled claims by or against the installer, a construction company and insurers following cracks appearing in the furniture. These claims involved product liability, construction, professional indemnity, insurance coverage, and Third Parties (Rights against Insurers) Act issues.
• Acted for a world-leading home appliances manufacturer defending claims relating to a repair action concerning defective printed circuit boards. Advised on when to admit liability, limitation defences, causation (competing cause), expert evidence, and issues relating to the spoliation of evidence.
• Advised an insurer of home appliances on cases relating to fires from dishwasher appliances, in particular in relation to whether a standstill agreement had expired.

Jason advises on high-value property disputes, including multimillion-pound dilapidations and lease covenant claims, possession proceedings, break notices, and rent recovery, with experience spanning the Chancery Division, Court of Appeal, and Technology and Construction Court.

• Edlington Properties Limited v J H Fenner & Co (2006). Had conduct of the case at first instance (Chancery Division) as well in the Court of Appeal. The underlying claim was worth £52 million.
• Fairgate International Limited v Citibank International PLC (2005). Acted in a dilapidations claim issued in the Technology and Construction Court. Valued at £19 million. The reported element of the case concerned the disputed interpretation of a number of lease covenants, decided as a preliminary issue. The subsequent claim required analysis of complex expert evidence from building and valuation surveyors.
• Serving break notices, and notices under the Landlord and Tenant Act 1954.
• Seeking possession under the 1954 Act.
• Recovering rent and possession on various grounds.
• Dilapidations claims.

Jason advises on negligence claims against solicitors, surveyors, and tax advisors, including multimillion-pound disputes over failed planning advice, lease processes, and contract completion, as well as sensitive claims arising from care-related fatalities.

• Claim against a chartered surveyor re alleged failure to serve a counter-notice in a rent review process concerning a letting in Brent Cross Shopping Centre (value of claim £1 million).
• Defended a tax advisor in a claim by a client relating to failed tax planning advice (value of claim £8 million).
• Defended a solicitors’ firm in a claim by a commercial property developer for failing to complete in accordance with the terms of a conditional contract for sale (value of claim £2 million).
• Acted in claims brought by claimants as the family of a person who died in care.

Jason represents clients in high-value, sensitive disputes, including personal injury claims, stolen goods, subrogated negligence actions, and complex inquests, acting for global corporations, insurers, and high-net-worth individuals in multi-jurisdictional and specialist matters.

• Represented a foreign royal family member in respect of a serious personal injury allegation made by an ex-employee at their UK residence.
• Acted for Samsung in relation to a stolen shipment of batteries, intercepted on its way to a major car manufacturer supplied by Samsung.
• Advised on a subrogated claim against a subcontractor for negligence in the supply and installation of bespoke decorative wooden panels for a display at a nature centre in Norway.
• Acted for the insurers to a large and multi-centre private specialist vein centre who are an interested party to the Coroner’s inquest into the death of a patient after vein surgery.

Jason advises insurers on complex medical liability claims, including alleged negligence in surgery, diagnostics, and treatments, representing providers, specialists, and multi-centre clinics, and navigating inquests, professional standards, and high-profile, sensitive disputes.

• Advised RiverStone Management insurers in the defence of a long-running claim by a professional boxer against the client, also brought against the boxing governing body, Senior Medical Officer, and the fight promotor for alleged failures to safeguard the boxer.
• Advised the insurer of one of the UK’s largest independent providers of intraoperative monitoring used during spinal surgery on the defence of a claim relating to alleged failures during scoliosis correction surgery of a patient with cerebral palsy.
• Successfully negotiated the defence of insurers to a medical and aesthetics company, in a claim for alleged negligence in the performance of a cryotherapy treatment.
• Advised insurers on a claim made against an optician with regard to the alleged failure to diagnose a malignant tumour on an optic nerve in respect of a minor who then died from the tumour.
• Acted for the insurers to a large and multi-centre private specialist vein centre, which is an interested party to the Coroner’s inquest into the death of a patient after vein surgery.

Jason is a leading product liability lawyer representing global manufacturers in complex fire, injury, and recall cases, often resolving disputes through mediation and advising on risk management, governance, and compliance.

• Defended a German sports car manufacturer in respect of a claim concerning an unexplained fire in the engine of a car. Used a number of experts from different fields of expertise to prove that the cause of fire could not have been a manufacturing defect.
• Acted for German-based lift manufacturer, in a claim by the owner of an office block relating to a defect which caused a catastrophic failure and lift mechanisms to fall several storeys.
• Settled at mediation a claim against a geotechnical engineer relating to a poorly designed flood defence.
• Acted for an electronics giant in a 5-year cease & desist in relation to “unapproved practices” in the use of products causing numerous claims in relation to fire and personal injury. This campaign targets all aspects of the supply chain and is conducted in conjunction with the Office for Product Safety and Standards and local Trading Standards departments.
• Successful mediation of a damages claim off the back of an inquest against a private healthcare group.
• Acting for a major name in household appliances defending claims relating to product recalls, damages for fire, flood and personal injury including infant settlement hearings to approve settlements. Delivering training to operations personnel on claims handling, consumer rights, liability and reputation management
• Acting for a blue-chip group on substantial product liability cases including a stream of actions relating to defective miniature circuit breakers in consumer units causing fires and leading to litigation, mediations, and settlements
• Acting for an international automotive manufacturer on claims relating to a product recall in scooters and motorbikes, with issues of contributory negligence by the users.
• Successful mediation of a claim for significant losses from a faulty swimming pool lining causing widespread damage to the rest of the property.
• Successful mediation of a claim for defective installation and a faulty water tank causing substantial flood damage to the property.
• Successful mediation of a claim for losses relating to a defective basement sump pump and issues of user failures.
• Acted for a German precision cutting and software manufacturer in relation to a claim for allegedly defective handheld controllers.
• Acted for a private healthcare group as interested party to an inquest involving significant expert evidence and cross-examination by the coroner, a company policy and procedure review and overhaul of governance in order to satisfy non-issue of a Regulation 28 Notice Prevention of Future Deaths.

Recognised by The Legal 500 for Insurance and Reinsurance Litigation 2017–2026

Recognised by The Legal 500 for Product Liability: Defendant 2020–2026