Every project changes. The client swaps a finish, the consultant revises a detail, and the site imposes a solution that was never on the drawings. The problem is not the change itself — it is that changes are executed immediately and quickly, while they are recorded, priced and approved slowly, or never approved at all. This is a guide to managing that gap: from the moment an instruction is given to the moment the money lands in a certified payment application.
Key takeaways
- A variation is not "extra work" — it is work the contract does not already oblige you to do, and the scope lives in the drawings and specification, not the bill of quantities.
- A verbal instruction is not invalid; it is unprovable. A same-day written confirmation is what turns it into an entitlement.
- Each variation has one correct pricing basis out of four, and choosing the wrong one costs more than arguing over the number.
- A single register with three states — instructed, priced, approved — stops entitlements from being lost inside somebody’s inbox.
- Time is a separate claim from money; claiming money alone reads as waiving the extension.
What actually counts as a variation
The question that settles most disputes is not "is this extra work?" but "does the contract already oblige me to do it?". If the answer is no, it is a variation and it earns a price and possibly time. If the answer is yes, executing it creates no entitlement however hard or unexpected it turned out to be.
Which is where the most common error comes from: treating the bill of quantities as the scope. The BOQ is a measurement and pricing instrument; the scope is defined by the drawings, the specification and the contract conditions. A missing BOQ item for work that is clearly drawn is usually a re-measurement question, not a variation.
- Work added that was not on the drawings or in the specification — a variation.
- A specification or material type changed by instruction from the client or consultant — a variation.
- A change to sequence or working hours imposed by instruction — a variation, and usually one whose effect is on time rather than quantity.
- Work omitted — also a variation, in the negative, and it may require a look at overhead recovery.
- Redoing your own defective work — never a variation.
- Changing method by your own choice to speed up output — not a variation; that is an internal decision at your cost.
The instruction you cannot prove
The serious losses do not happen in the pricing meeting. They happen on site in the morning, when the client’s representative says "do it now and we will sort it out later". The work gets built, the file gets opened two months on, and by then the argument is about a conversation with no reference and no date.
Do not start without a written instruction — where you can
This is the ideal, not always the reality. But make it the default, and make the exception a conscious decision by the project manager rather than a habit of the site engineer.
Confirm the verbal instruction the same day
A formal letter or email: "Further to your verbal instruction today, [date], at [location], we have commenced…". Sending it the same day is what makes the record contemporaneous, and contemporaneous is what gives a document its weight.
Reserve cost and time expressly
One sentence: "our rights in respect of cost and time are reserved; a valuation will follow within the contractual period". Its absence is later read as having proceeded without reservation.
Record it in the daily report
The labour and plant used on the change, the disruption hours if any, with dated photographs. The daily report is what turns your claim from an assertion into a measurement.
Chase silence in writing
If no reply arrives within a reasonable period, send a reminder noting that the work is proceeding under instruction and that cost is accruing. Silence you did not chase gets read against you.
A verbal instruction is not invalid. It is merely unprovable — and the difference between the two is a three-line letter sent the same day.
The four pricing bases
Every variation has one correct pricing basis, and their order is not arbitrary: start from contract rates, then rates derived from them, then a new rate built from first principles, and only then daywork. Submitting a new analytical rate when a comparable contract item exists is the quickest route to having the whole valuation returned.
| Basis | When it applies | What to watch |
|---|---|---|
| Contract rates | Work identical in character, executed under similar conditions | A rate is tied to the conditions it was priced under: quantity, timing, location |
| Pro-rata rates | Similar work under different conditions — deeper level, smaller quantity, higher floor | The adjustment must be explained line by line, not as a vague percentage uplift |
| New analytical rate | Nothing comparable exists in the contract | Built up from labour, materials and plant with the stated overhead and profit percentages |
| Daywork | Work with no measurable output — demolition, cleaning, standby support | Requires daywork sheets signed as the work happens; an unsigned sheet is worth nothing later |
The point most often missed: a contract rate is not an abstract number, it is a number priced for a set of conditions. Pouring a thousand cubic metres in one continuous operation is not the same job as pouring twenty in a tight corner after the finishes are in. Claiming a different rate there is not opportunism, but it has to be argued in the language of conditions rather than the language of objection.
One register, three states
Projects rarely lose variations because they were rejected. They lose them because the variations disappeared: an instruction in an inbox, a quotation in a folder on an engineer’s laptop, an approval given verbally in a meeting. One register is the difference between a number you manage and a number you discover missing at final account.
| Column | Why it is needed |
|---|---|
| Sequential reference | One reference used in every letter, valuation and application |
| Instruction date and source | Starts the notice clock and anchors the evidence |
| Short description and location | Prevents confusing two similar changes in different buildings |
| Status | Instructed / priced / approved / rejected — with the date of each transition |
| Value submitted and value certified | The gap between them is the real negotiation number |
| Time effect in days | Keeps the time claim visible instead of buried inside a money figure |
| Application number it was claimed in | Prevents claiming twice, and prevents never claiming at all |
- Instructed: an instruction exists and has been confirmed in writing, with no valuation submitted yet. This is where the contractual clock starts.
- Priced: the valuation is submitted and awaiting response. This column is your "value at risk", and management should see it monthly.
- Approved: written approval of a defined amount exists — and only then does the amount enter a payment application.
From instruction to money in an application
An approved variation is not the end of the process; it is the start of the financial one. The money reaches your account only through a payment application, so the order and timing of these steps decide when you get paid, not merely whether.
Submit the valuation inside the period
Even if it is preliminary and subject to adjustment. An estimate on time is stronger than a complete valuation that is late, because the first preserves the entitlement and the second can forfeit it.
Separate money from time
Present the cost effect and the time effect as two distinct items. Merging them turns approval of one into implicit rejection of the other, and that is how most extension entitlements are lost.
Never put uncertified variations in an application
Including an unapproved change exposes the whole application to rejection and a full cycle of delay. Show it in the value-at-risk report instead.
Claim approved variations in the very next application
Every month of delay in claiming is another month of self-financing work you executed and paid for long ago.
Chase weekly, in writing
A short list of outstanding variations, sent weekly with references and dates. Regular follow-up moves the file from "we will look at it" to a standing item on the consultant’s desk.
Where the money actually leaks
Final accounts repeat the same causes. All of them are procedural, and all of them close with ordinary discipline rather than legal expertise.
| Cause | Preventive action |
|---|---|
| Building on a verbal instruction with no written confirmation | A same-day confirmation letter and one named correspondence log |
| Missing the notice period | An automatic reminder the moment a register entry is opened |
| Variation cost mixed into base project cost | A separate cost code per variation from day one |
| Claiming money but not time | A mandatory duration field on the valuation form that cannot be left blank |
| Pricing on the wrong basis | A written rule: contract rates first, analytical rates only where nothing comparable exists |
| Forgetting to claim an approved variation | A monthly reconciliation between the register and the drafted application |
The conclusion is that variation management is not a negotiating skill but an operating habit: record the instruction on the day, price it on the right basis, track it in one register, and claim it the moment it is approved. Four steps that take a few scattered hours a month — and decide a meaningful share of the project’s profit in return.
Frequently asked questions
Can we refuse to carry out a variation?
Usually not, if it was issued the way the contract requires and falls within the variation clause. But the clause has limits: work different in character from the contract works, or a change that transforms the value of the contract, may sit outside a unilateral variation power. The practical position is to proceed while reserving your rights in writing rather than stopping, because a wrong stoppage turns you from claimant into defaulter.
What if the client later denies the verbal instruction?
Your position depends entirely on what you did that day: a confirmation letter with a date on it, a daily report recording the work and the labour, dated photographs, perhaps meeting minutes. Contemporaneous documents are what carry weight. Reconstructing the story from memory two months later rarely succeeds.
Does every variation earn an extension of time?
Not automatically. You earn time where the variation affects activities on the critical path of the programme. That is why the time claim is submitted separately and supported by programme analysis, rather than added as a remark at the end of a financial valuation.
How is omitted work treated?
An omission is a negative variation: the value of the omitted work comes out. Two cautions, though. The omission may increase the overhead burden carried by the remaining items, and most contracts do not permit omitting work from one contractor to hand it to another. The second case is a claim in its own right, not simply a deduction.
When should we stop work if a variation is not approved?
Stopping is a high-risk decision and rarely the contractually correct answer. The practical response is escalation built on a number: report total value at risk monthly and its effect on cash flow. A figure moves a file faster than a threat, and it protects your position if the matter ever becomes a dispute.
One variation register, from instruction to application
Record the instruction on the day, track each variation’s status, value and time effect, and claim approved ones in the next application — in Arabic and English.