Section 1 states the entitlement and the reasoning in full. Sections 2 and 3 are the windows analysis and the concurrency treatment that produce it — these are the parts a respondent will test. Section 4 states the method and its limits.
Appendix A is the window register with the contemporaneous evidence relied on for each; Appendix B sets out the impacted-network calculation day by day; Appendix C records the provenance of every file used.
The net critical delay of 18 calendar days resolves into 12 days of excusable, compensable delay (employer risk) and 6 days of non-excusable delay (contractor risk).
A 12-day concurrency exists between the employer and contractor events. Because those days overlap, the contractor's cost recovery for the compensable window is reduced or extinguished for the concurrent period, while the extension of time remains due.
Recommended EOT award: 12 days, with the residual 6 days remaining at the contractor's risk. The 12 days arise from the Employer's failure to respond to RFI-214 in due time, a Relevant Event under clause 2.26 and a Relevant Matter under clause 4.21. The 6 days arise from the contractor's own re-sequencing of Grid G steel erection beyond the period of concurrency. Loss and expense for the concurrent 12 days is not recommended; time is.
It establishes what the programme shows and how the contract's delay provisions apply to it. It is not a legal opinion and does not determine quantum. Where the concurrency principle applied here is contested — and the treatment of concurrent delay remains contested in principle — section 3 sets out the alternative outcome so the parties can see the range rather than a single asserted answer.
Three windows were analysed between the R10 baseline and the R12 update. Each window impacts the network as it stood at the start of that window, so the effect of each event is measured against the plan actually in force at the time rather than against the original baseline.
02–14 August 2027 · impact +12 calendar days on the critical path. The Level 3 pre-pour inspection (activity A1733) was held pending the Employer's response to RFI-214 concerning a rebar detail. Under JCT D&B 2016 clause 2.26 a failure to provide information in due time is a Relevant Event giving rise to an extension of time, and a Relevant Matter under clause 4.21 giving rise to loss and expense. This is an excusable, compensable delay. The window is measured from the date the pour became due to the date the RFI response was received and the pour released.
10–28 July 2027 · impact +18 calendar days gross on the critical path. Erection of columns at Grid G, Levels 4–6 (activity A1422) was re-sequenced after fabricated steel was re-issued. This is a contractor-risk, non-excusable delay. For 12 of these days the effect ran concurrently with the tail of the employer-driven pre-pour hold; the remaining 6 days sit as pure contractor-culpable delay beyond the concurrency.
Non-critical · no entitlement arises. Open-ended logic on the MEP rough-in chain (A1801) was closed during R12, revealing six days that had already been lost but were not visible while those activities had no successors. This is a disclosure correction, not a delay event: no party caused it in the window, and it confers no entitlement in either direction. It is recorded because it affects the arithmetic and would otherwise appear as unexplained movement.
An as-planned-impacted analysis run once against R10 would credit the full 18 days of W2 and the full 12 of W1 to their respective parties and miss that they overlap. Windows preserve the sequence, which is the only way the concurrency in section 3 becomes visible.
Twelve of the eighteen days are concurrent: during that period both an employer-risk event and a contractor-risk event were independently delaying completion.
The approach taken here is the conventional English-law position: the contractor recovers time but not money for the concurrent period. An extension of time is granted for the full 12 days of the employer-risk event, because the employer cannot hold the contractor to a completion date that the employer's own act contributed to preventing. Loss and expense is not recommended for those days, because the contractor would have incurred the prolongation cost in any event by reason of its own concurrent delay.
| Period | Days | Cause | EOT | Loss & expense |
|---|---|---|---|---|
| Concurrent | 12 | W1 employer + W2 contractor, running together | Due | Not due |
| Contractor only | 6 | W2 beyond the concurrency | Not due | Not due |
| Net critical delay | 18 | 12d | nil |
The treatment of concurrent delay is not settled and the contract does not address it expressly. On an apportionment approach — as applied in Scots law and occasionally argued elsewhere — the 12 concurrent days would be shared, producing an EOT in the range of 6 to 12 days and a corresponding partial recovery of loss and expense. The parties should be aware that the recommendation in section 1 sits at the top of that range, and why.
The analysis follows a windows / time impact methodology aligned to AACE International RP 29R-03, using the contemporaneous programmes actually submitted rather than a retrospectively constructed plan.
Produced from fictional project data for illustration. No real schedule, client, contractor or contractual position is used or implied. Nothing here is legal advice.
Each window with its bounding dates, the activity impacted, the measured effect and the contemporaneous records relied on.
| W | Event | Window | Activity | Impact | Risk |
|---|---|---|---|---|---|
| W1 | Level 3 pre-pour hold — RFI-214 | 02–14 Aug 27 | A1733 | +12d | Employer |
| W2 | Grid G steel erection rework | 10–28 Jul 27 | A1422 | +18d | Contractor |
| W3 | MEP rough-in logic correction | R12 update | A1801 | nil | Neither |
| W | Record | Dated | Establishes |
|---|---|---|---|
| W1 | RFI-214 as issued | 28 Jul 27 | Date the information was requested |
| W1 | RFI-214 response | 14 Aug 27 | Date the pour was released |
| W1 | Site diary, pour hold entry | 02 Aug 27 | Date the pour became due |
| W2 | Steel re-issue notice, fabricator | 06 Jul 27 | Cause of the re-sequence |
| W2 | Revised erection sequence drawing | 09 Jul 27 | Scope of the rework |
| W3 | — | — | No contemporaneous record; derived from programme comparison alone |
W3 is deliberately shown with no supporting record. A window whose only evidence is the programme itself cannot support an entitlement claim, and stating that is more useful than omitting the row.
The completion milestone position after each window is inserted and the network recalculated. Movement is cumulative down the table.
| Step | Network state | Completion | Move | Cumulative |
|---|---|---|---|---|
| 0 | R10 baseline as approved | 01 Nov 27 | — | 0d |
| 1 | W2 inserted — Grid G rework | 19 Nov 27 | +18d | +18d |
| 2 | W1 inserted — pre-pour hold | 19 Nov 27 | +0d | +18d |
| 3 | W3 — disclosure correction | 19 Nov 27 | +0d | +18d |
| Net critical delay, R10 to R12 | +18d | +18d | ||
W1 adds nothing once W2 is already in the network, and this is precisely what concurrency looks like in the arithmetic. Reversing the insertion order gives the mirror image: W1 first produces +12d and W2 then adds only 6. Neither order is more correct, which is why the 12 overlapping days are treated as concurrent in section 3 rather than credited to whichever event happened to be inserted first.
| Insertion order | W1 attributed | W2 attributed | Total |
|---|---|---|---|
| W2 then W1 | 0d | 18d | 18d |
| W1 then W2 | 12d | 6d | 18d |
| Concurrency-adjusted (adopted) | 12d | 6d | 18d |
The total is stable at 18 days under every order; only the attribution moves. Publishing the sensitivity is the honest way to present an analysis whose result depends on a modelling choice.
Every file relied on, with the figures taken from it, so the analysis can be reproduced independently.
| Role | File | Data date | Activities | Completion |
|---|---|---|---|---|
| Baseline | TowerC_R10_2025-11-30.xer | 30 Nov 25 | 3,610 | 01 Nov 27 |
| Intermediate | TowerC_R11_2026-01-31.xer | 31 Jan 26 | 3,744 | 09 Nov 27 |
| Update | TowerC_R12_2026-02-28.xer | 28 Feb 26 | 3,842 | 19 Nov 27 |
| Figure | This brief | Baseline Comparison | Agrees |
|---|---|---|---|
| Net critical delay | 18d | 18d | Yes |
| Gross event duration | 36d | 36d | Yes |
| Employer-risk days | 12d | 12d | Yes |
| Completion date | 19 Nov 27 | 19 Nov 27 | Yes |
The two reports are produced from the same files and must agree on the facts even where they differ in purpose. Any divergence would indicate an error in one of them.
Every report in the set is built from a Primavera P6 or Microsoft Project file, parsed in your browser. Nothing is uploaded and nothing is retained.