NEC Option A - Design changes

We are under contract on an Option A for a design and build and recently submitted our design to the client. We have submitted our design as per clause 21.2 and the design complies with the WI and all applicable law

The client wants to make changes however there changes are not changes to the WI. Making the client recommended changes may save us (the contractor) on material costs. The client has then said they want the money back as a negative CE for the savings.

To me this does not seem right as (a) the WI has not changed and (b) we will now be expending more design hours due to making these small changes.

Does the Client have a right to change design and request we give money back?

You say your client ‘want you to make changes’. How does that come about?

If they have withheld acceptance of the design, and you are sure it does comply, then you could notify a CE under 60.1(9); but how would you assess that? It seems possible that it will be a negative sum, even after design costs are accounted for, based on the information here.

If they have accepted the design and made a suggestion, there is no contract route, it is merely a suggestion. You can action it or not. There is an argument about that not being fair on the client, but by selecting Option A they already made their decision; in other forms they would obtain benefit.

There is also the possibility that the client could, via the PM, instruct the changes to the design by modifying or adding to the WI, which would be a CE.

So, the answer to your question is no, but there could be turns in the road.

Assuming the contract has procedure and share values, it looks to be an issue to be explored as Value Engineering. But if the materials are of the same quality/specification as the current works information requirements, there is no change, no CE and no change to the prices.