The extension of time was awarded and the money wasn't

The award felt like the finish line. The time was granted, the damages threat fell away, and everyone went back to running the job. Months later the account tells the other half of the story: the site ran for those extra weeks at full cost, the supervision, the cabins, the plant, the management time, and none of that money has followed the time.

It does not follow automatically. The time side is settled ground; what remains is a quantum exercise, and a separate one. The cost of an extended period has to be built from the records of the period: the actual time-related costs that ran on, evidenced line by line, not the tender preliminaries divided by weeks and multiplied out. Assessors distinguish sharply between the two, because one is what the delay cost and the other is what somebody once hoped the job would cost.

The build also has to keep its own discipline: running-on costs separated from any thickening claimed during the works, overlap with money already recovered through variations stripped out, so nothing is claimed twice. Done that way, the money behind the time is one of the more provable claims on a job, because the period is already established and only the cost of it is in question.