Tower C — Commercial Tower & Podium

Programme R12 update vs R10 approved baseline

Client

Meridian Estates (owner)

Contractor

Calderwood Construction Ltd

Baseline

R10 — approved 30 Nov 2025

Update

R12 — data date 28 Feb 2026

Contract

JCT D&B 2016

Activities

3,842 (2,970 matched)

Baseline finish

1 November 2027

Current finish

19 November 2027

Delay summary

Baseline finish

1 Nov
2027

Contract completion per approved R10 baseline

Current forecast

19 Nov
2027

Forecast completion per R12 update

Net critical slip

+18d

Net movement of the longest path to completion

Delay events

Distinct events on or joining the critical path this period

Net slip is the movement of the driving path. Gross delay events total +36 days; +18 days were absorbed by float or mitigation and are non-critical.

Contractor-risk delay: +18d critical Employer-risk delay: +12d (concurrent) Mitigation recovered: −18d

Delay waterfall — how the finish date moved

Bridge from R10 baseline finish to R12 forecast finish (critical-path calendar days)

Critical delay path — what changed between revisions

R10 path A1390 Steel del.→ A1422 Grid G cols→ A1560 Deck L4–6→ A1801 MEP rough-in→ A2240 Core handover

R12 path A1390 Steel del.→ A1422 Grid G cols +18d→ A1733 Pre-pour hold +12d→ A1801 MEP rough-in +6d→ A2240 Core handover

shifted activity remained on the driving path but moved later · new activity joined the driving path this period (was previously off-path with float).

Activity-level delta — critical & near-critical movers

Activity	Name	Cause	Risk	Baseline finish	Current finish	Slip
A1422	Erect columns Grid G, L4–6	Steel erection resequenced after fabrication re-issue	Contractor	10 Jul 27	28 Jul 27	+18d
A1733	Pre-pour inspection, Level 3	Held pending employer response to RFI-214 (rebar detail)	Employer	02 Aug 27	14 Aug 27	+12d
A1801	MEP rough-in, Zone A	Open-ended successor logic closed; true position revealed	Contractor	19 Aug 27	26 Aug 27	+6d
A2104	Curtain wall install, North	Resequenced to run parallel with cladding (mitigation)	Mitigation	03 Sep 27	23 Aug 27	−11d
A1390	Structural steel delivery, Grid G	Fabrication shift added to recover erection window	Mitigation	14 Jun 27	07 Jun 27	−7d
Net movement of driving path to completion						+18d

Concurrent delay assessment

Two delays overlapped for 12 days — entitlement is apportioned, not additive

Contractor delay (A1422, Grid G steel resequence): ran from 10–28 Jul 27, driving the critical path by 18 days. This is a contractor-culpable delay.
Employer delay (A1733, pre-pour hold on RFI-214): ran from 02–14 Aug 27, a 12-day employer-risk event. For 12 of those days it was concurrent with the ongoing effect of the Grid G resequence.
Net position: because the two events were genuinely concurrent for 12 days, neither party can claim the full period. On a first-in-time basis the contractor delay begins the critical slip; the employer event does not extend it further while concurrent. The 12-day employer event is relevant to any EOT application but does not add to the 18-day net.
Flagged for review: the apportionment above follows a "dominant cause / first-in-time" reading. If the contract or the parties prefer an apportioned approach (e.g. City Inn), the split changes — this is a legal determination, not a scheduling one.

Variance narrative

Between the approved R10 baseline and the R12 update, the forecast completion of Tower C moved from 1 November 2027 to 19 November 2027 — a net critical slip of 18 calendar days. Gross delay across all events on or joining the driving path totalled 36 days; 18 days were recovered through resequencing and a fabrication acceleration, leaving 18 days net.

The delay originates in the structural steel scope at Grid G. Activity A1422 (erect columns, Levels 4–6) slipped 18 days after the fabricated steel was re-issued and the erection sequence had to be reworked. This is the single event driving the revised finish date, and it is contractor-risk.

A second, employer-risk event then joined the path: the Level 3 pre-pour inspection (A1733) was held for 12 days awaiting the employer's response to RFI-214 on a rebar detail. Critically, this event was concurrent with the tail of the Grid G resequence, so although it is a legitimate employer delay it does not add to the net figure — it is quantified separately in the concurrent-delay assessment above for any extension-of-time application.

The MEP rough-in (A1801) contributed a further 6 days, but this is largely an artefact of closing previously open-ended logic rather than a new physical delay: the R10 baseline understated the true position because the successor link was missing. Closing it revealed the correct forecast, which is itself a quality improvement.

Mitigation was effective. Running the north curtain wall parallel with cladding recovered 11 days on A2104, and an added fabrication shift pulled steel delivery forward 7 days. Without these, the net slip would have been 36 days rather than 18. The programme remains recoverable, but the Grid G steel scope should be treated as the controlling risk for the next reporting cycle.

Methodology

Activity matching. The two revisions are reconciled by unique Activity ID, with a fallback fuzzy match on activity name and WBS path for renamed or re-coded activities. 2,970 of 3,842 activities matched directly; added, deleted and split activities are listed separately in the Excel appendix.

Critical-path derivation. The driving path to completion is traced through total-float ranking and longest-path logic in each revision independently, then compared. An activity is reported as "new to path" when it carried positive float in R10 and zero or negative float in R12.

Concurrent delay. Concurrency is detected where two or more independent delay events overlap in time on or affecting the critical path. Apportionment shown uses a dominant-cause / first-in-time reading; ScheduleInsight quantifies the overlap but does not make the legal determination of entitlement.

Limitation. This comparison reflects the two schedules as submitted. It does not incorporate correspondence, site records, or contemporaneous notices beyond what is encoded in the schedules themselves. A full delay analysis for formal claim purposes is produced by the Claim Brief report.

This is a condensed sample. The live Baseline Comparison report is considerably more extensive — generated from your own P6 or MSP files with full activity-level detail, deeper forensic analysis and complete supporting appendices.