A Cross-Jurisdictional Comparison of a Contractor’s Duty to Warn of Design Defects Under English Law and French Law

Professor Anthony Lavers and Rebecca Shorter

November 2025

Published in the SCL Journal: Autumn 2025 

This paper considers the circumstances when a contractor may come under a duty to warn the employer, or the employer’s contract administrator, of deficiencies in the design which the contractor has undertaken to build. The authors look at the sources of the duty, in contract and in tort (in England) and in civil code and contract (in France and Italy), examining whether actual knowledge of the design defect is needed, what the contractor must do to fulfil its duty, and the state of development of the duty. In doing so the paper reviews the relevant case law and compares common law and civil law approaches to these issues.

Introduction – Part I: English law – Sources of law: contract and tort – (i) Express contractual provisions – (ii) Implied contractual provision – (iii) Tort – The requirement of actual knowledge – Fulfilment of the duty to warn: what must be done –  Conclusions: direction of travel – Part II: French and Italian law – Civil sources of law: civil code and contract – (i) Civil code – (ii) Express contractual provisions – The requirement of actual knowledge – Fulfilment of the duty to warn: what must be done – Conclusions: direction of travel –  Conclusion: comparative view

The authors: Professor Anthony Lavers is a Visiting Professor at King’s College London and a Research Consultant at Crown Office Chambers. He is a former Chair of the Society of Construction Law.
Rebecca Shorter is a barrister practising from Crown Office Chambers and was a member of the Paris bar. She is the current Chair of the Society of Construction Law.

Text: 28 pages