An obvious example would be where a compensation event requires more work to be undertaken which does not affect the planned Completion date. This may include; additional procurement, more subcontracts, possibly with new Subcontractors, site supervision, greater contract administration managing Subcontracts and also the consequent actions under the main contract, Health and safety inductions and assessments, Quality management and compliance with thew Quality Plan (condition requirement under NEC4). etc
The less obvious are where the additional scope creates inefficiencies and requires more time to co-ordinate activities, programme the works and further extends the time for associated reporting requirements, such as; progress/ earned value / H&S stats, Non Conformance Reporting, Labour allocation returns etc..
It is not a straightforward assessment, however, as People's effort necessarily fluctuates throughout a project lifecycle and the usual argument of what is allowed in the tender as opposed to what should have been allowed always surfaces at this point.