The parties in this case were in dispute over the assessment of concurrent delays to works under a JCT Design & Build Contract 2005. Of particular interest here was the fact that the employer relied on a clause that is often included by way of amendments in such contracts. This clause sought to exclude the contractor's right to an extension of time to completion where there was concurrent delay as between a relevant event and a non-relevant event.
A common counter to such an exclusion clause is based on the prevention principle - that is that (as applied in this case) any extension of time clause that seeks to exclude the contractor's right to an extension of time where the employer has itself 'prevented' the contractor from completing its works by the completion date is invalid. This argument is often tied up with arguments/misunderstandings as to the meaning of concurrency in such situations.
Here we examine the implications of the case and explain the rationale in the context of the current judicial interpretation of concurrency.