Loss and expense, and why time is a separate question

These two get merged constantly, in claims and in conversation. They are different things.

The lists that trigger them overlap but are not identical. Under JCT, extensions of time run off Relevant Events; loss and expense runs off Relevant Matters. Some events appear on both lists, some on only one.

Exceptionally weather is the clearest example. Adverse weather conditions may justify an extension of time. They do not, on standard JCT terms, carry loss and expense. The contractor gets relief from damages and funds its own prolongation.

Ascertained, not estimated

The contract says loss and expense is ascertained. That word is doing real work. Ascertainment means establishing the actual loss from evidence, not applying a formula to a period of delay.

This is why formula-based claims struggle. A calculation that takes head office overhead, applies a percentage and multiplies by weeks of delay produces a number, but it does not demonstrate that the sum was actually lost. It may be a useful cross-check. It is not, on its own, ascertainment.

What is typically recoverable

• Prolongation of site costs. Site establishment, supervision, plant and welfare for the extended period, at actual cost
• Disruption. Reduced productivity in the affected work, which requires evidence comparing actual output to what was reasonably achievable
• Increased preliminaries where time-related and genuinely extended
• Head office overheads and profit, where the contract permits and the loss can be shown
• Finance costs on the sums involved, where the contract allows
• Additional subcontract costs passed down and actually incurred

Where these claims fail

No causal link

A claim that establishes a delaying event and establishes a loss, without connecting the two, has done half the work. The connection must be shown for each head of loss, not asserted globally.

Notice not given

Most contracts require the contractor to notify when the regular progress of the works is being or is likely to be affected, and to do so as soon as it becomes apparent. Late notice weakens a claim and under some amended contracts defeats it entirely.

Records that do not exist

Ascertainment requires records made at the time: labour allocation, plant returns, progress records, correspondence. A claim assembled from monthly cost reports two years later cannot show what was actually lost on the affected activities.

Concurrency handled badly

Where a contractor delay and an employer delay overlap, the position on time and the position on money are not the same. Concurrency is a genuinely difficult area and it is one where a surveyor should be reaching for advice rather than a rule of thumb.

The client-side discipline

Loss and expense sits awkwardly in interim valuations. The contract entitles the contractor to have ascertained sums included, but ascertainment takes time, and a claim submitted is not a claim ascertained.

The wrong responses are to include the claimed figure to keep the peace, or to include nothing for months while the ascertainment stalls. Both create problems: the first is difficult to unwind, the second builds pressure that resurfaces as a larger claim.

The workable middle is to ascertain what can be ascertained as evidence arrives, include that, and state clearly in the certificate what remains unascertained and what is needed. That way the contractor knows where it stands and the record shows the process was engaged with.

The practical point

Almost everything above depends on records made while the work was happening. The claim is won or lost long before anyone writes it, by whoever did or did not keep the allocation sheets.

This is a general summary and not legal advice. Concurrent delay and global claims are contested areas; take advice on significant claims.