These two percentages are there to cover and - once tendered and accepted - avoid any argument over what the contribution to your profit and off Site overheads is due to compensation events i.e. your margin.
So a starting point for working them out is, for the job, look at what your estimated site-based costs will be, what your tendered Prices are and the difference, expressed as a percentage, gives you these percentages.
You then need to make a commercial decision on whether you want more or less which, in part, will depend upon any rules/guidance given by the Employer form how they will be used in the tender assessment.
So a starting point for working them out is, for the job, look at what your estimated site-based costs will be, what your tendered Prices are and the difference, expressed as a percentage, gives you these percentages.
You then need to make a commercial decision on whether you want more or less which, in part, will depend upon any rules/guidance given by the Employer form how they will be used in the tender assessment.