Daywork Rate Calculator

Daywork is a method of valuing extra or varied work that cannot be properly measured or valued using contract rates. Work is charged at cost (prime cost) plus agreed percentage additions to cover overheads and profit. It is typically agreed in the contract as a fallback for unmeasurable variations.

The RICS Definition of Prime Cost of Daywork sets out the method — prime cost of labour, materials and plant plus a percentage addition for incidental costs, overheads and profit — but it does not publish recommended percentage figures. The additions are agreed between the parties and stated in the Contract Particulars. In practice, typical market additions are Labour ~130–160%, Materials ~10–20% and Plant ~5–15% (negotiated, not RICS-mandated). The labour addition covers incidental costs, overheads and profit (site supervision, head-office charges, employer’s liability insurance, small tools, welfare, profit) — it does NOT cover employer’s NI, holiday pay or pension, because those are already part of the prime cost (the all-in hourly rate you enter).

Daywork should only be used when work cannot be valued by measurement - typically unforeseen problems, complex variations, or emergency work. It should be agreed in advance and daywork sheets signed daily by the client representative.

A daywork sheet must record: date, description of work, operatives names and hours, materials used with costs, plant/equipment used with hire rates. It should be signed by both the contractor and the client/architect representative, ideally on the same day.

Overtime is typically charged at 1.5x (time and a half) for weekday overtime and 2x (double time) for weekends and bank holidays. The percentage addition is then applied on top. Always confirm overtime rates in the contract before undertaking the work.