The Contractor Delays the project by 4 weeks (the Planned Completion moves 4 weeks, the Completion date stays the same, the PC is therefore 4 weeks later than the C).
The PM then instructs a CE adding work that extends previously non critical activity that now ends on the Planned Completion date (and is now also critical).
Should the Completion Date be moved out to the Planned Completion milestone or stay 4 weeks behind.
It is a bit like the mechanics of using float except it is the movement of PC and C in delay scenario.
Taken in isolation, by the criteria in clause 63.3 of NEC3 or the 63.5 in NEC4, it should not add anything on to the Completion Date as planned Completion is not delayed.
However, the Contractor’s risk of being later is, in simple terms doubled, as it has two paths of operations which could cause a further planned Completion to go back as opposed to the original one. Consequently, under clause 63.6 (NEC3) / 63.7 (NEC4) the Contractor is entitled to some additional time &/or monies due to the increased risk.
Thanks Jon, much appreciated.