We are acting as the project manager on a NEC4 ECC Option A (priced contract with activity schedule) using secondary option X7 delay damages. The contractor is showing planned completion being later than the completion date, although this date has not yet been reached. Therefore, delay damages, at the rate stated in the contract data, should be retained in our first certified payment assessment of the amount due occurring after the completion date. The client would prefer that we hold back from retaining delay damages from our assessment until nearer completion and take over. If we do not retain delay damages when we are obliged or entitled to do so, will we waive the right to recover the delay damages later?
The contract requires the project manager to retain delay damages when assessing the amount due after the completion date, see clauses X7.1, 50.2 and 51.2. The client can, of course, pay more than you have certified if they wish. We would therefore suggest you think very carefully about this, as you will, in effect, be breaching the requirements of the contract.
If, for example, you were employed under an NEC4 Professional Service Contract (PSC), it could be argued that you have not used the skill and care normally used by professionals providing services similar to those you are providing (see clause 21.2 in the PSC).
As for the waiver issue, that is a legal question and you would need to seek legal advice on this.