I think the answer is No.
Whatever procedure the Employer may have in place does not alter the way in which the contract obliges each Party to do, unless the contract was amended appropriately.
If you have a standard Option X16, then retention is halved at completion (within the next payment assessment) and is effectively 0% (nothing retained) when the Defects Certificate is issued. It looks like you have a 12 month period between completion of the whole of the works and the issuing of the Defects Certificate. This is only extended where a Defect is notified and the defects correction period runs past the 12 month date.
Any contract requirements that you may have with regard to 'handover' (Delivery Into Use, Bringing Into Service etc), is a separate contract procedure and should not be confused with the retention provisions under Option X16, which are very clear.
Whatever procedure the Employer may have in place does not alter the way in which the contract obliges each Party to do, unless the contract was amended appropriately.
If you have a standard Option X16, then retention is halved at completion (within the next payment assessment) and is effectively 0% (nothing retained) when the Defects Certificate is issued. It looks like you have a 12 month period between completion of the whole of the works and the issuing of the Defects Certificate. This is only extended where a Defect is notified and the defects correction period runs past the 12 month date.
Any contract requirements that you may have with regard to 'handover' (Delivery Into Use, Bringing Into Service etc), is a separate contract procedure and should not be confused with the retention provisions under Option X16, which are very clear.