An extension of time is not automatically money

What an extension of time buys

A granted extension moves the completion date. Its practical effect is protection from liquidated damages: the pre-agreed rate the employer may deduct for late completion cannot be levied for the extended period. That is the whole prize on the time track, and it is worth having, because liquidated damages accrue whether or not anybody is arguing about causation.

What it does not buy

It does not pay for the delay. Prolongation cost, disruption and extended preliminaries are recovered, if at all, through a separate mechanism with its own trigger list, its own application requirements and its own standard of proof. Under the JCT forms that mechanism is loss and expense, and the trigger list is the Relevant Matters, which is a different list from the Relevant Events that earn time.

Under NEC the position looks different because a compensation event adjusts time and money together, but the same discipline applies underneath: the money is assessed from Defined Cost and the Fee, not from the length of the extension.

Events that earn time but not money

• Exceptionally adverse weather, on many forms: a neutral event where the risk is shared as time without cost.
• Events outside either party’s control, where the contract grants relief from damages but allocates the cost to the contractor.
• Concurrent periods, where an extension may be granted but prolongation cost for a period the contractor would have been in delay anyway is generally not recovered.

Events that cost money without moving completion

Disruption to work that was never controlling completion can generate real additional cost and no extension at all. Claims that assume the two always travel together miss this in both directions, and it is one of the most common reasons a claim is under-pleaded rather than over-pleaded.

The practical consequence

Run the two assessments separately from the start, with separate evidence and separate notices. A submission that treats the extension as the answer to the money leaves the commercial case to be reconstructed later, usually by somebody who was not there.