What are construction claims?
A formal request under a construction contract for additional money or time, or both, arising from an event the contract places at the other party's risk, made and evidenced in the way the contract requires.
Updated: 15 September 2026. By Jack Butler-Kettle, Quantity Surveyor & Claims Consultant.
The answer
A construction claim is a request under the contract for something the claimant says it is entitled to and has not been given: more money, more time, or both, because of an event the contract puts at the other party's risk. The money claims are for the value of changed work, for loss and expense or additional cost caused by the other party's acts or defaults, for prolongation and disruption, and, going the other way, for damages, defects and set-off. The time claims are for extensions of the completion date. Every claim has the same four parts: the contractual basis, the event and its cause, the effect, and the amount, and each part needs its own evidence. The word covers everything from a two-line variation account to a forensic reconstruction of a project's costs, and the difference between a claim that is paid and one that is not is almost always the records behind it rather than the argument in front of it. This practice does the money side, called quantum; the time side is done by others.
Example
The situation
A subcontractor's steelwork is delayed six weeks by late design information, and the subcontractor puts together a claim for the money and, separately, for the time. The money claim has four parts.
What happens
- The basis is set out: the instruction and the contract's loss and expense or compensation event clause.
- The event is set out: the late drawings, with the dates requested and received.
- The effect is set out: the crews and crane standing, shown in the labour and plant returns.
- The amount is set out: those resources priced from the records, plus the preliminaries for the period.
- The extension of time for the same six weeks is made as a separate claim by the same subcontractor on the same facts.
The outcome
The claim has a basis, an event, an effect and an amount, each tied to a document, and the time claim runs beside it on the same facts.
Claim Preparation and Assembly turns the records into the amount.