11.01 The well-worn expression “time is money” is particularly apt in the context of construction and engineering projects. Delays to the completion of a project almost inevitably result in an increase in cost to the contractor, and the suffering of some form of loss by the owner (eg, a loss or deferment of revenue). Construction and engineering projects can be delayed for a variety of reasons.1 Common examples include a contractor’s dilatoriness or negligence, the owner having ordered increased or varied works, or adventitious matters such as poor weather. Contracting parties’ rights and obligations consequent upon a delay are determined largely by the allocation of risk for delay prescribed by the contract in question. The concept of “delay”, in this context, is not always synonymous with “sloth” or “dilatoriness”. The critical matter is what the contractor has promised to do, that is, by when did the contractor promise to complete the works, or some part of them?2