NEC ECC: Option B and changing rates?

We are in working under the NEC3 option B form of contract and the quantities in the bill have significantly reduced from the tender. If there has been no change to the Works Information, is this a Compensation Event under 60.4 as the unit rates now need increasing, as for example, prelims were requested to be spread across rates which means we are now under recovering this element?

Prelims were spread across rates and also outputs were not achievable as economies of scale could not be achieved. Is a reduction in quantity a CE under NEC3 option B and can all affected rates be amended?

Providing it meets the requirements in the 3 bullet points of 60.4, the answer is ‘Yes’.

The most contentious of these is that the FINAL quantity x rate is more than 0.5% of the original Prices.