NEC ECC: Compensation Event assumption

if quotation is accepted with “assumed work can be unaffected by poor weather” but bad weather is encountered. Is it a CE?

The contract allows for Project Manager assumptions within a quotation, which if in turn out not to be correct would lead to an additional compensation event to assess the difference. If a Contractor has put an assumption and the quote has been accepted, that does NOT make that assumption a Project Manager assumption and is a lot greyer now as to what that means.

The advise is always to either get the Project Manager to state the assumptions, or otherwise price the risk.

On your specific example - either way you need to be much more specific in terms of “poor weather”. With regards to weather, worse than a 1 in 10 year event is a CE, whilst up to a 1 in 10 year event is Contractor risk. Contractor is allowed to include risk within their compensation event quote which has a significant chance of occurring and is their risk under the contract.