JCT Major Projects - discrepancy in Period for Completion

Currently working on a project where the Main Contract has a defined Completion Date and the Sub Contract has a Period for Completion. As a result of the Period for Completion, the Sub Contract Completion Date is later than the Completion Date in the Main Contract.
The Sub-Contractor has a Period for Completion of 100 weeks but if the defined Completion Date within the Main Contract applies (the Main Contract is a Numbered Document within the Sub-Contract) then the period for Completion is 90 weeks. When assessing Sub-Contractor EOT would it be appropriate to base that assessment on a 100 week period or a 90 week period?


The fact that the Main Contract is a numbered document, is not by itself a criterion for assessing the Sub-contractor’s EOT - you would have to look at the modifications schedule to identify this and any priority of documents in the event of conflict, discrepancies etc.

The Sub-contract may refer to the progress of the Main Contract works, but it is usually the programme details in the Sub-contract particulars that the fixing of the period for completion is based on.

In absence of any further details, my answer would be the 100 week period.