C's Proposal used to Change WI

We are a contractor operating under the NEC3 ECC Option C contract. Our site engineers raised a proposal to alter the design of a steel riser for some utility services due to the poor quality of the retaining wall towards the top. The proposal was to look at an alternative restraint location, with the one suggested resulting in a smaller riser and subsequent cost savings.

The PM has taken this information and used it to change the WI by removing the riser entirely, does this still fall under the provisions of the first bullet point of clause 63.11 and that the Prices should not be reduced?

Yes this would still fall under the exception at clause 63.11. The Employer will benefit by the reduction in Defined Cost and any consequential saving against the Prices. Your site engineers probably wouldn’t have made the proposal if you weren’t going to benefit commercially.