Notes · Concurrent Delay
Concurrent delay: time yes, money no
When an Employer delay and a Contractor delay hit the same window and both drive the critical path, that is concurrent delay — not mere overlap. The rule that usually follows is short: time yes, money no. But whether it is apportioned depends on where you are. Shown step by step.
What counts as concurrent delay
The SCL Delay and Disruption Protocol describes concurrent delay as two or more events occurring at the same time, each an effective cause of delay to the completion date. The word that does the work is effective. Concurrency is judged on the critical path, not on the calendar: two things happening in the same week is mere overlap. Genuine concurrency needs an Employer-risk event and a Contractor-risk event that would each, on its own, have driven completion later in that window.
Put plainly: overlap is just two delays happening at the same time; concurrency is two delays that are each, on their own, pushing the finish date. Say the Employer hands over a work front late, and in that same week the Contractor’s own crew is short-staffed. If both — taken separately — would have delayed completion, that is genuine concurrency. But if the crew had spare time and only the late hand-over actually moved the end date, the short-staffing is just overlap, and it is not concurrent delay at all. The distinction decides real money, because only genuine concurrency triggers the time-yes-money-no rule.
The core rule: time yes, money no
Where genuine concurrency exists, the mainstream position is that the Contractor is entitled to the extension of time — which protects it from liquidated damages — but not to prolongation cost for the concurrent period, because its own delay would have kept it on site anyway. Time is granted; the money is not. So I keep the two questions strictly apart, and I never let a time argument quietly drag the cost along with it.
But the split depends on where you are
That rule is an English-law default, not a universal one. Apportionment — dividing the delay between the parties — is treated very differently across jurisdictions, and for a Gulf project the UAE line matters most:
| Jurisdiction | Approach to concurrency |
|---|---|
| England & Wales | Malmaison / Walter Lilly — full EOT, no apportionment of time; no prolongation cost for the concurrent period. |
| Scotland | City Inn — time may be apportioned between the parties. |
| UAE | Civil Code causation, good faith and contributory fault — tribunals tend to apportion, especially on cost; FIDIC 2017 Sub-Clause 8.5 now addresses concurrency directly. |
| Saudi Arabia | Civil Transactions Law — an apportionment-oriented environment; liability divided on contributory fault. |
How you prove it
Whichever way the law leans, the delay analysis is the same discipline. I run a windows / time-slice analysis, and in each window I separate three things cleanly: periods of exclusive Employer delay, periods of exclusive Contractor delay, and the periods that are genuinely concurrent. For each I show, on the records, what would have happened if only the Employer’s event had occurred, if only the Contractor’s had, and what actually happened. That factual, per-window picture lets a tribunal apply whichever principle its law prefers — a full EOT, or an apportioned outcome.
I don’t call two delays “concurrent” just because they happened at the same time. I prove that each one, on its own, actually delayed completion — window by window — and I keep the time question and the money question separate.