In a recent blog about global claims Paul Slinger dealt with the case of Walter Lilly and Mr Mackay and commented that the case also provided a commentary on concurrency of delay events which would be dealt with in a future blog.

Well here is that blog.

The law on concurrent delays in relation to JCT contracts in England and Wales has a history. It really started with the 1999 Malmaison case. In that case the parties agreed that where there were two concurrent causes of delay and one was a Relevant Event and one was not, then the contractor was entitled to an extension of time. The judge accepted this, but it was never entirely clear whether he reached his own conclusion or simply went along with what the parties had agreed between them.

In 2010 a Scottish case, City Inn Ltd v Shepherd Construction Ltd, suggested that a contractor should only get an extension of time for a reasonably apportioned part of the concurrent delay.

Since then the English courts have suggested that Malmaison remains the law of England and Wales and that was categorically confirmed to be the case by the judge in Walter Lilly where he said

" where delay is caused by two or more effective causes, one of which entitles the Contractor to an extension of time as being a Relevant Event, the Contractor is entitled to a full extension of time".