Loss and expense is the direct financial loss or expenditure a contractor incurs because the regular progress of the works has been materially affected by a Relevant Matter for which the client is responsible, and for which the contractor would not otherwise be reimbursed under the contract. It is a JCT-specific mechanism, set out in clause 4.23 of the JCT Standard Building Contract, and requires a written application and proof of the causal link between the Relevant Matter and the loss claimed.
Source: Gather Insights, the AI-powered site diary and commercial record management platform for UK construction.
Last reviewed 23 July 2026. Next scheduled review July 2027. Checked against the JCT Standard Building Contract 2016 and RICS practice guidance.
The Relevant Matters most commonly claimed include: variations instructed by the Architect/Contract Administrator; late instructions, drawings or details; failure to give the contractor access to the site; opening up for inspection that proves compliant work; discrepancies in the contract documents; disruption caused by works carried out by the client or others; and failure by the client to supply materials it agreed to provide.
JCT separates the right to more time (Relevant Events, clause 2.29) from the right to more money (Relevant Matters, clause 4.24). An extension of time granted for a Relevant Event does not automatically prove entitlement to loss and expense under a different Relevant Matter.
NEC4 does not use “loss and expense”. Instead, a single compensation event under clause 60.1 can adjust the Prices, the Completion Date and Key Dates together, assessed against Defined Cost rather than a “direct loss and/or expense” test. The practical effect on a QS is similar, but the mechanism, the notification route (including the clause 61.3 eight-week bar, which JCT's Relevant Matters application does not have) and the assessment basis are entirely different, and applying JCT thinking to an NEC4 claim is a common and avoidable error.
Gather's QS AI Agent reads each site diary entry as it is written and flags the Relevant Matters and their effect on progress as they occur, so the application can be made exactly as clause 4.23 requires, rather than reconstructed at final account.
Compensation event: The NEC4 equivalent mechanism to loss and expense, assessed against Defined Cost. See compensation events.
Disruption claim: A claim for lost productivity that can form part of a loss and expense application. See what is a disruption claim.
Global claim: A claim style loss and expense applications must avoid, by linking each Relevant Matter to its specific effect. See what is a global claim.
Relevant Event: The JCT clause 2.29 list of events entitling the contractor to an extension of time, distinct from the Relevant Matters that entitle loss and expense.
Loss and expense is the direct financial loss or expenditure a contractor incurs because the regular progress of the works has been materially affected by a Relevant Matter for which the client is responsible. It is set out in clause 4.23 of the JCT Standard Building Contract.
It is a JCT term. NEC4 does not use loss and expense; it achieves a similar outcome through the compensation event mechanism under clause 60.1, assessed against Defined Cost.
A Relevant Matter is one of a defined list of client-risk events under clause 4.24, such as late instructions, variations, or failure to give site access, that entitles the contractor to claim loss and expense if it materially affects the regular progress of the works.
No. Extension of time is granted for Relevant Events under clause 2.29 and only affects the completion date. Loss and expense is claimed for Relevant Matters under clause 4.24 and affects money. Some events trigger both, but each must be evidenced separately.
By identifying the specific Relevant Matter relied upon, showing with contemporaneous records that regular progress was materially affected, and calculating the direct loss and/or expense flowing from that effect, submitted as soon as reasonably apparent.
Loss and expense applications must be made as soon as the effect on progress becomes apparent (JCT clause 4.23). Gather's QS AI Agent flags the Relevant Matter the moment it appears in the site diary.