Answered: NEC ECC: Option A (Contractor Design) and updating Contractor's Works Information

You may be confusing Contractor's Works Information (CWI) - in place at the signing of the contract - with detailed design developed by the Contractor after the contract has been signed.

If your CWI complies with the Employer's WI, then if the PM wants to change its, it is a compensation event and the sooner the PM changes it the less the impact.

If the detailed design developed by the Contractor complies with the WI, regardless of whether it is the Employer's or Contractor's or both, but the PM does not like it and wants to change it, then it is a compensation event and the sooner the PM changes it the less the impact.

If you build the asset in accordance with the detailed design (which is in accordance with the C's WI and that in turn is in accordance with the E's WI), then it is not a Defect as defined in the contract.

Lastly, you do not have to submit your detailed design to the PM for acceptance except if it is stated in the WI that you have to. If this is not the case for an element of design, then the sooner the PM states this and changes the WI to reflect it, then the more you can plan for it, the less impact on the programme and the less the change to the Prices (if any).