If a contractor is not granted the extension of time to which he is entitled, he may be faced with the possibility of liquidated damages being levied against him. He has a stark choice. He can continue to work as planned and (presumably) efficiently in the hope that a proper extension of time will be granted by the Architect/Engineer ("A/E"). Alternatively he can accept that he is in default, at least temporarily, and increase resources and reorganise the work.

The measure of the resulting acceleration costs is not always obvious, so the choice is difficult. In addition the contractor has to judge the real risk of levy of liquidated damages since he may eventually be granted an extension of time.

If the contractor is successful in accelerating the works then he may find that he has no or a reduced entitlement to an extension of time. He will have succeeded in avoiding the levy of liquidated damages, but may find that this was not a risk in any event, because he had an entitlement to an extension of time. On what basis therefore can he claim recovery of the costs incurred as a result of this uncertainty?

The essential question is whether the failure of the A/E to grant an extension of time is a breach of contract by the Employer, entitling the contractor to the additional costs for constructive acceleration?

A single failure to grant an extension of time is unlikely to be such a breach. Many standard forms of contract envisage several stages in the determination of extensions of time by the A/E, with an interim assessment followed by final review at some later stage. There will therefore be a contractual remedy for the A/E’s failure.

Usually no term will be implied requiring the Employer to oversee or supervise the Engineer`s functions of certification and decision making under the contract. If there is an arbitration clause the parties will normally agree to the arbitrator having the power to open up, revise and review any certificates, decisions or opinions. In the absence of an arbitration agreement the parties frequently agree to the Courts having the same power. In such cases, if the contractor wishes to challenge any interim decision, he can request the appropriate adjustment in the next stage of the process or if this is refused go to arbitration or the courts to have the decision corrected. There will therefore be a formal remedy for the A/E’s failure.

If there is no power either by an arbitrator or the Courts, to open up, revise and review decisions then a contractual duty will be implied that the Employer should oversee or supervise the A/E`s functions. It is suggested however that this duty is easily discharged by the Employer.

In practice it will therefore be difficult to base a constructive acceleration claim on a single failure of the A/E to grant an extension of time. It may be possible to mount such a claim for the A/E’s express refusal or continuing failure or unnecessary or unreasonable delay in dealing with the application for extension of time.

The next question which arises is when can the A/E be considered to have failed to grant an extension of time? This will be a matter of fact and depend upon the terms of the contract. It is suggested that at the very least the contractor is entitled to an early indication of the A/E’s decision on individual grounds as they arise. This is vital to the contractor’s decision whether or not to accelerate.

It is clear that a claim based on constructive acceleration presents significant legal difficulties. However a claim for disruption costs based on the events which gave rise to the original request for extension of time may still be possible. There will be fewer legal difficulties since there is at least a substantial body of caselaw. It will be necessary however to demonstrate that the acceleration action taken was a reasonable mitigation of the loss.

Faced with the above legal difficulties, the contractor is best advised to take the following actions before deciding to accelerate the works: