Should you price the scheme until planned completion or the completion date at the start of the job? I presume planned Completion.
Yes you are correct. You only need to price for “prelim” type costs to your planned Completion which should give you a commercial edge over your competitors at tender stage. If there is a delay to planned Completion you get to price the full impact of that which will include any additional prelim type costs even if that is still within the original Completion Date. Clause 63.3 emphasises that the effect is measured against planned Completion.