Construction delay analysis identifies the causes, responsibility and contractual consequences of delayed work. Harper James advises businesses on construction disputes and contracts under the laws of England and Wales, including the assessment of extension of time and loss and expense claims.
The analysis begins with the contract programme, approved revisions, progress records and the contractual completion date. The relevant events are then identified, such as variations, late information, changes in statutory requirements, restricted access, payment issues, adverse weather or contractor underperformance. Each event must be dated and linked to the work affected. Site diaries, meeting minutes, instructions, drawings, requests for information, photographs and updated programmes provide the supporting evidence.
A delay affects the contractual completion date only when it affects activities on the critical path, meaning the sequence of work that controls project completion. Analysts compare the planned programme with actual progress and assess the effect of each delaying event at the time it occurred. Common methods include a time impact analysis, which inserts an event into the contemporaneous programme, and a windows analysis, which examines progress during defined periods. The chosen method should reflect the quality of the records, the contract requirements and the nature of the dispute.
The contract determines whether a delay event gives the contractor an extension of time, additional payment, or both. Under many JCT contracts, relevant events primarily address time, while relevant matters address financial loss and expense. NEC contracts use different terminology and procedures, including compensation events. Notice requirements, submission deadlines and obligations to provide updated programmes must be followed. A contractor generally establishes entitlement by proving the event, contractual compliance, causation, critical delay and the resulting costs.
Concurrent delay arises when two effective causes delay completion during the same period, with one attributable to the employer and the other to the contractor. Its treatment depends on the contract wording and applicable case law, and the analysis must distinguish true concurrency from sequential or overlapping events. A reliable claim therefore maintains a live programme, records delay events promptly, separates employer-caused delay from contractor-caused delay, and calculates proven additional costs rather than relying on broad estimates. Clear records often determine whether a delay claim is resolved through agreement, adjudication, arbitration or litigation.