NEC ECS: Under NEC3 ECS, can a Contractor communicate change to a Subcontractor on a response to a Technical Query?

We are a subcontractor, however acting as the main contractor.

We were unsure on a specification, so asked a TQ. Our client responded to our TQ, with a specification that was a change to works information. However, this change in specification was missed. The work was carried out to the original works information. As we were not notified of any change. The change in information was missed by the us the subcontractor.

Are we as the subcontractor, liable for the cost to put the incorrect specification correct? Or is the contractor?

I think this turns on the phraseology used in that response to your TQ. If it can be ‘reasonably’ construed as an instruction from the Contractor to do the work as per the new specification. But what that ‘reasonable’ looks like in practice is subjective, hence why you want to be administrating the contract as written.

So TQs in future should be ‘early warning notifications’ perhaps with a sub-categorisation of a TQ … . And if you are not sure whether something is an instruction or not, early warn for clarification and if they confirm it is an instruction changing the Works Information and the Contractor does not notify as a compensation event, then you do so.