Failure to complete in time may make the contractor liable to pay liquidated damages, as specified in the contract, to the employer. Hence at the time a completion certificate is issued, the engineer must decide whether any extension of the time for completion is allowable. Extensions of time may have to be allowed if the contractor is delayed by problems for which the employer is liable under the contract. These should have been notified as they arose and considered at the time (see Section 17.10). There may also be sections of the work which the contract requires to be completed earlier than for the project as a whole. It is important to note that not all delays will lead to an extension.
Some may not affect the path to completion and others may be matters for which the contractor is responsible. It is necessary to check with the contract conditions (such as ICE 7th edition Clause 44) to identify which delays are to be taken into account, such as exceptional adverse weather conditions, etc. Assessment of extensions of time may have to be made several times during a long contract and their cumulative effect will have to be assessed at or near completion. The assessment needs to take account of all known circumstances at the time, independently of what may happen later. Also the estimate is unlikely to be precise because of complicating factors, such as delay periods overlapping. The engineer has to decide whether delays fairly entitle the contractor to an extension, so it may be that reference only to the contractors
programme is insufficient, since other factors need to be taken into account to produce a fair result. To make this judgment the engineer needs experience of constructional processes and their limitations.
An early look at a delay with reference to the contractors initial programme, should take into account that this is only a statement of intent and that the contractor is at liberty to change his programme. Some operations will, in the nature of events, take longer or shorter to complete than anticipated.
Amore realistic approach is to examine the as-built record of construction to see if had the delay not occurred the construction could have been completed faster, taking into account any changes made by the employer which have caused delay. The advantage of this approach is that it is based on actual performance including any mitigating measures that were taken to reduce delay.
Afurther discussion of assessing delay and evaluating any payment due is given in Sections 17.10 and 17.11.