Tracking variations before they become disputes
The variation that ends up in a dispute is almost never contested on the day it happens. On the day, everyone agrees. The architect says move the door, the site manager says fine, the joiner reworks the studwork that afternoon. The argument arrives months later, at the final account, when the money is discussed for the first time and nobody can agree what was said, by whom, or whether it was an instruction at all.
The fix is not better negotiation at the end. It is better capture at the start: a dated record of who instructed what, when, and what it looked like, created at the moment of instruction rather than reconstructed for the argument. Firms that get this right stop treating variations as fights. They become routine commercial hygiene, priced and agreed while everyone still remembers the conversation.
Why do verbally agreed variations go wrong?
Because the agreement on site is about the work, and the disagreement later is about the money, and those are two different conversations separated by months.
The site conversation settles scope: yes, move the door. Nobody prices it in that conversation, because pricing it feels like making a fuss over something small. The classic form is the instruction issued with cost "to be agreed", which means cost to be argued about later, and that phrase has a well-worn path to the final account. By the time the quantity surveyor asks for substantiation, the wall is plastered, the operative has moved on, and the only evidence is memory.
Memory is exactly what the other side's memory disagrees with. Disputes are never born big; they are born as a small gap in the record that both parties fill in their own favour.
How do JCT and NEC actually handle changes?
Differently in mechanism, identically in what they reward: contemporaneous records.
| JCT | NEC | |
|---|---|---|
| The change mechanism | Architect's or contract administrator's instruction, valued under the valuation rules | Compensation event, notified and quoted under clauses 60 to 65 |
| Who starts the clock | Often nobody: instructions can arrive informally and get regularised later | The contractor, who must notify within eight weeks or risk losing entitlement |
| Where verbal changes sit | Provisions exist for confirming oral instructions in writing, and they are widely ignored | An unnotified event is commercially invisible, however real the work was |
| What wins the argument later | Evidence of the instruction and the conditions at the time | Evidence of the event, the notification date and the quotation basis |
Notice the shared final row. Under JCT the valuation rules tell you how to price the change, but they cannot tell you whether the change was instructed; only the record does that. Under NEC the process is stricter, and a late notification can bar the claim entirely, which makes the date of the record the single most valuable fact you hold.
What does a good variation record contain?
Five things, all cheap to capture on the day and expensive to reconstruct later.
Who gave the instruction, in what words. When, to the day and ideally the hour. What the work involved, in enough detail that a stranger could price it. What the affected area looked like before and after, which is two photographs. And what was said about money, even if the answer is nothing.
Most of that already exists on a live project. It sits in the site WhatsApp group: the message asking for the change, the photo of the opened-up wall, the voice note from the contracts manager. The problem is not capture, it is that the capture happens in a channel nobody treats as a project record. The message is there, but nobody can find it in March when the argument is about last September.
The Society of Construction Law Delay and Disruption Protocol makes the same point from the disputes end: contemporaneous records are the foundation of both avoiding and resolving disputes, and their absence is what turns a valuation difference into a credibility contest. RICS guidance on contract administration points the same way: administer the contract as events occur, not in retrospect.
Why does the record matter more than the valuation?
Because valuation is arithmetic and entitlement is evidence, and only one of those can be done later.
Two competent surveyors given the same facts will land within touching distance on the number. What they cannot do is agree the facts when the facts were never written down. Was it an instruction or a suggestion? Was the work extra or was it snagging? Did the delay flow from the change or from the weather? Every one of those questions is answered cheaply by a dated message and a photograph, and expensively by correspondence between solicitors.
A firm with a clean variation record rarely needs to fight, because the other side can read the same record. The dispute dies at the point someone opens the file and finds the instruction, dated, with a photo attached.
What does capture at the moment of instruction look like?
Not a form. Forms lose to the pace of a live site every time. It looks like the channel people already use, feeding a record they never have to think about.
If the instruction arrives in the site group, the message, its sender, its timestamp and its photos are already structured data; the missing step is filing them against the project, the location and the change, automatically, on the day. That is precisely the kind of system Construction Metric exists to provide, and the kind of thing AI Metric builds for firms with their own workflow quirks. The test of any version of it is simple: when the final account meeting turns to variation 14, can you put the instruction on the screen in under a minute?
If you can, the meeting is short. Variations stop being the place margins go to die and become what they should have been all along: work you did, evidenced, priced and paid.