Dayworks Explained: When to Use Them, and How to Actually Get Paid
Dayworks are the fallback when work cannot be measured or priced in advance — and the single most commonly rejected item on a UK contractor's account. Here's when they apply, what a sheet must contain, and why signatures are worth more than rates.
Short answer: Daywork values work at cost plus an agreed percentage, and it exists for work that genuinely cannot be measured. It is the last option in the valuation hierarchy, not the convenient one. Sheets get paid when they carry an instruction reference, contemporaneous detail and a signature — and get rejected when they arrive late, unsigned, or describing work that could have been measured.
Where daywork sits in the valuation hierarchy
Standard forms differ in wording but agree on the order. When work is varied, it is valued:
That hierarchy is not advisory. A quantity surveyor assessing your account will apply it, and will move an item down the list wherever they can. If a variation could have been valued at contract rates, it will be — even if you submitted daywork sheets for it, and even if those sheets were signed.
The signature does not convert measurable work into daywork. Signing usually confirms that the resources recorded were on site and did the work described. It rarely confirms that daywork was the right basis. This surprises contractors constantly.
When daywork genuinely applies
Work that resists measurement, typically because the scope was unknown until it was uncovered:
- Opening up and investigation. Nobody can measure what is behind the wall before it is opened.
- Remedial work to unknown existing conditions. Chasing a leak through a floor void, cutting out unexpected asbestos-adjacent build-ups, following corroded pipework to sound material.
- Attendance and standing time caused by others, where the resource was on site and unable to proceed.
- Small, scattered, non-repetitive works where the measurement effort would exceed the value.
- Emergency and out-of-hours works instructed with no time to price.
What the sheet has to say
A daywork sheet is a contemporaneous record, and it is judged as evidence. The elements that make one payable:
| Element | Why it matters |
| Date of the work | Must match the site records — diary, timesheets, delivery notes |
| Project, location, area | "Site" is not a location; the room or grid reference is |
| Instruction or variation reference | Proves someone with authority asked for the work |
| Description of work done | Specific enough that someone who was not there can picture it |
| Why it could not be measured | The justification for using daywork at all — routinely omitted |
| Operatives by name and trade, with hours | Names, not "3 x labourer". Names can be checked against timesheets |
| Plant by item, with hours on site | Distinguish operating hours from standing hours |
| Materials with quantities | Supported by invoices or delivery notes |
| Signature of the client's representative | With their printed name, role and the date signed |
Signatures: what to chase, and from whom
Get the sheet signed at the time, ideally the same day, always by someone whose authority you can name. A signature collected three weeks later from whoever is available is worth substantially less, because the signatory is confirming something they cannot now verify — and they know it, which is why they hesitate.
If the client's representative will not sign, do not simply file the sheet. Send it anyway, in writing, noting that it was presented for signature on a given date and that no signature was provided, and inviting them to record any disagreement. An unsigned sheet with a contemporaneous covering record is far stronger than an unsigned sheet found in a folder at final account.
Where the representative signs "for record purposes only", that is still worth having. It fixes the resources and the date, which are the facts most often disputed later.
The percentage addition, and what it already covers
Daywork is priced as prime cost plus a percentage for overheads and profit. Where the RICS and Build UK Definition of Prime Cost of Daywork carried out under a Building Contract applies, the definition sets out precisely what falls inside the prime cost of labour, materials and plant, and the contractor tenders the percentage additions.
The recurring dispute is double-counting. Items already inside the definition — certain statutory costs, holiday credits, elements of supervision, small tools — cannot then be added again as separate line items. If your percentage was tendered on the assumption that the definition applies, it has to be applied to the defined prime cost and not to a differently-assembled cost.
Two practical points:
- Know which definition your contract names, and price accordingly at tender. Percentages tendered against one basis and applied to another produce arguments nobody wins.
- Standing time is not automatically payable. Plant standing because your own works were not ready is your cost. Plant standing because of an instruction, a client delay or a failure of attendance is a different matter — and the sheet needs to say which.
Why sheets get rejected
In rough order of frequency:
Note how many of these are records problems rather than commercial ones. The typical rejected daywork account is not too expensive; it is unprovable.
Making dayworks reconcile by default
The reason daywork records fail internally is that the same hours are recorded three times, in three places, by three people: on the sheet, on the timesheet, and in the site diary. Any divergence between them is a gift to the other side.
The fix is to record hours once and let the daywork sheet, the timesheet and the diary be different views of that record. When an operative clocks onto a job and the hours are allocated to the variation, the daywork sheet is assembled from the same data that produced payroll — so the two cannot disagree.
ScopeKit ties labour, plant and materials recorded on site back to the variation they were instructed under, so daywork sheets, timesheets and the daily diary reconcile because they draw on one record rather than three. The instruction reference and signature travel with the sheet, and the cost lands against the job's financial position rather than surfacing at final account.
A short discipline that pays
- Raise the instruction reference before the work starts, even if the value is unknown.
- Write the "why this cannot be measured" line on the day, while the reason is obvious.
- Get the signature the same week.
- Submit within the contractual period, always.
- Reconcile sheets to timesheets weekly, not at final account.
Related reading
- Cost value reconciliation explained — where unrecovered daywork shows up as a margin hole.
- The RFI process — the record that usually precedes an instruction.
- The daily site diary — the contemporaneous record daywork sheets are checked against.
- Retention in construction — the other money routinely left on the table.
Frequently asked questions
- When is work valued as daywork rather than measured?
- Daywork is the last resort in the valuation hierarchy. Most standard forms of contract require varied work to be valued first at contract rates, then at rates derived from contract rates for similar work, then at fair rates, and only at daywork where the work is of such a nature that it cannot properly be measured and valued. Using daywork because it is easier is the most common reason a sheet gets rejected.
- What must a daywork sheet contain to be paid?
- The date, the project and location, the instruction or variation reference authorising the work, a description of what was done and why it could not be measured, each operative by name and trade with hours worked, plant by item with hours on site, materials with quantities and supporting invoices, and a signature from the client's representative. A sheet without an instruction reference or a signature is an invoice for work nobody authorised.
- How soon do daywork sheets need to be submitted?
- Most contracts require submission within a short period — commonly by the end of the week following the work, and sometimes within days. Late sheets are frequently rejected on that basis alone, regardless of merit, because the whole point of contemporaneous records is that the other side can verify them while the evidence still exists.
- What is the percentage addition on daywork?
- It is the uplift applied to net labour, materials and plant to cover overheads and profit, stated in the contract or in the contractor's tender. Where the RICS/Build UK Definition of Prime Cost of Daywork is used, the percentages are tendered by the contractor and applied to the defined prime cost. The critical detail is what the prime cost already includes, because double-counting an item that is inside the definition is a standard reason for a deduction.
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