Most standard form contracts provide for valuing of variation work which cannot be
properly measured and valued using daywork rates stated in the Contract Bills.
Where no such rates are stipulated, it is common to use actual prime cost of Contractor’s
materials, transport and labour for the variation work plus a percentage (usually 15%),
for the use of plant/equipment, tools, scaffolding, supervision, overheads and profit.
Often, where the variation work is to be on a daywork basis, the Contractor must maintain
daywork sheet/s duly completed and countersigned by the Architect/Engineer/SO or
its authorised representative, as the case may be, to verify the resources employed for
the variation work before any payment on this basis can be considered.
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