Query on add and delete referencing a tender rate

Good Afternoon,

Looking for some assistance on the following scenario from a live NEC 4 ECS option A contract (we are operating as a subcontractor)

Tender DWG’s show 8 louvres framed in to cold rolled framing on the exterior skin of the building. A new DWG was received which showed 10 and some got bigger and some got smaller. The client agrees this is a change. When preparing the build up, we have agreed SsoC rates, agreed fees and will work up the new louvres from first principles. The question is where is the credit applied to and for what rate? the tenders are worked up according to business standards, whereas the contract NEC quotes are worked up according to the contracts. Where are the rules that state the value of the credit from our original tender allowance? would it just be the cost basis and how would the fees etc stack up?

For clarity, we use an NEC template for quoting our events provided by this website.


You assess the change in Defined Cost + fee from the point of notification (i.e. a forecast of cost change). The overall quote for the change will show some items rising in cost and some falling in cost. This “may” lead to the contract Total of the Prices increasing, or decreasing as a result in the change.