An allowance/rate had been made within the Target cost which was agreed for the provision of blocking between joists of a heritage propoerty. The Contractor had advised that the rate for this blocking was based on dimensionally cutting the blocking to size with a chop saw but not scribing each piece of blocking to fit between the cupped joists (as directed by the Structural Engineer). Is the agreement for the rate for blocking classed as an assumption and therefore the additional difficulty associated with cupping of the joists and the required scribing classed as the correction of an assumption and therefore a Compensation Event.
Once you’ve entered into contract what was allowed for and how the target was priced is irrelevant. There will only be a compensation event if there has been a change to the Scope e.g. a new constraint has been introduced that requires a different method of working from one prescribed in the Scope. The assumption made pre-contract is not an assumption under clause 61.6 and therefore not an assumption that tiggers a compensation event under clause 60.1(17). Also the Contractor is required to Provide the Work in accordance with the Scope, not in accordance with the Activity Schedule therefore what was assumed pre-contract is again irrelevant.
Compensation event quotations / assessments are based on Defined Cost paid by the Contractor plus Fee and the Contractor is reimbursed in the same way. Rates and prices can only be used by agreement in accordance with clause 63.2.