Answered: NEC ECC: (Option C) - What defined costs can the Contractor apply for?

Whatever was included in the Contractor's activity schedule does not define the scope of works, which is essentially defined by the Works Information.  Under a main option C the activity schedule gives a total of the Prices, which is the 'target', with payments made using Defined Cost.

Any Defined Cost is incurred in order to Provide the Works, including Equipment, although it seems that what you are actually referring to is Plant (Equipment is used to Provide the Works whereas Plant is included in the works).  If that is the case, then you could treat this as a Disallowed Cost under 11.2 (25) 6th bullet.

If the Employer only specified one item in the Works Information then this is what should have been provided, regardless of what was stated in the activity schedule.  Although NEC doesn't have an 'order of priority' provision, clause 54 states that the activity schedule is not Works Information, which is the document that specifies and describes the works.

See also the case of Leander Construction Ltd v Mulalley and Co Ltd 2011, which dealt with the situation where requirements described in the activity schedule conflicted with the contract conditions.