NEC ECC: How to calculate the total of the Prices under Option C?

If using BQ, we can use the below two bullets to forecast the total of the Prices:

The total of the Prices is the total of:
The quantity of work which the Contractor has completed for each item in the Bill of Quantities multiplied by the rate and
A proportion of each lump sum which is the proportion of the work covered by the item which the Contractor has completed (see Clause 11.2(33)).

However, under Option C (Activity Schedule), how can we apply these principles to forecast the total of the Prices?

The definition of the Prices for option C is 11.2(30). At tender stage you produce an activity schedule and submit as part of the tender return to ascertain your target price that you are committing to. Each line item on the activity schedule should be priced, and the total adds up to the tendered sum - your total of the Prices

How you get paid (the definition for Defined Cost changes) for each ECC option so you need to look at clause 11 for each option for the definition. For options C and D the Contractor is not paid in relation to an activity schedule or B of Q - this is only used to ascertain the target price at tender stage. The Contractor under option C and D in very simple terms the actual cost they have spent (or forecast to have spent up until the assessment date) plus fee (full definition in 11.2(23). Any difference in the final cost and the target (which can be adjusted in line with implemented compensation events) will be shared according to the split identified in contract data part 1.