I would say the Contractor’s defined cost of people, according to the time they have spent working on the preparation of quotations (which could extend to designers, planners, quantity surveyors, operational people or even HSE advisors) should be included as part of all quotations in NEC4, where their expertise and input is required to accurately forecast, from a practical perspective, what the effect on defined cost is due to the CE – which is often very complicated.
If the people involved in preparing the quotation would have otherwise been undertaking other work (i.e. doing their day to day job) which, as a result of spending time working on the preparation of the quotation, had to be postponed then there is a valid argument that there is an effect on defined cost because the planned duration or time that person was intended to spend on the project may have extended, even if planned completion may not have changed. So long as the Contractor can clearly demonstrate this, there is no reason why such costs cannot be recovered.
On larger projects it’s quite common to have people/teams dedicated solely to preparing quotations and clause 62 programmes and dealing with change control generally.