Duty to warn
Duty to warn

The following Construction guidance note provides comprehensive and up to date legal information covering:

  • Duty to warn
  • When does a duty to warn arise?
  • How is the duty to warn discharged?
  • Implications for contractors/sub-contractors/consultants

This Practice Note examines the extent to which contractors, sub-contractors and consultants have a duty to warn their employer of inadequacies that they discover in designs that have been produced, or works that have been carried out, by others.

If a contractor or a sub-contractor identifies an error in designs that are provided to it, for it to build, by their employer or a consultant, does the contractor/sub-contractor have a duty to draw such flaws to the attention of its employer? If a consultant thinks that a contractor is carrying out (or may carry out) works negligently, should it warn its client? What is its potential liability if it does not?

When does a duty to warn arise?

There is no general ‘duty to warn’ in English law but, in certain circumstances, such a duty can be imposed.

Implied duty

Under some building contracts, the contractor has express design responsibility and therefore is clearly responsible for any flaws or inadequacies in it (see Practice Note: Design liability in construction contracts). In others, where the contractor/sub-contractor does not have liability for the design, there may still be some contractual requirement for it to bring inadequacies, inconsistencies etc in the design to its employer’s attention so that they can be resolved (see, for example, clause 2.15 of the JCT Standard Building Contract With Quantities