When to raise a variation

A variation is a change to the contracted scope. Something is added, removed, substituted or changed after the contract was signed, and the price and often the programme change with it.

What counts

Situation	Variation?
Client asks for a different benchtop	Yes
PC allowance exceeded by the client’s selection	Yes — the difference
Latent site condition — rock in the excavation	Yes
Design change from the architect	Yes
Council imposes an extra requirement	Yes
You underestimated the brickwork	No — that is your risk
A supplier raises their price mid-job	No, usually — check your contract
Client deletes the deck	Yes — a credit variation

The line is whether the scope changed, not whether the cost changed. Your own estimating error is not a variation. A client’s change of mind is, even when it saves money.

Raise them immediately

This is the whole thing.

A variation raised the day the client asks for the change is a conversation about a price. The same variation raised two months later, after the work is built, is a conversation about whether they agreed to it — and those conversations are lost more often than they are won.

Unwritten variations are the most common way builders lose money

Verbal agreement on site is not a record. If the client asks for something and you build it without a signed variation, you are relying on their memory and their goodwill at the exact moment they are least inclined to have either — when the final claim arrives.

The process

1. Raise the variation as soon as the change is known — see Creating a variation.
2. Price it, including any extension of time.
3. Send it to the client for approval.
4. Get it accepted before the work is done.
5. The contract sum moves, and the variation becomes claimable.

Step four is the one under pressure on a live site, and the one worth holding the line on.

Credit variations

A variation can reduce the contract. The client deletes the deck, the price comes down.

Raise these with the same discipline as additions. A documented credit is evidence that you passed the saving on, and it keeps the contract sum accurate — which matters because progress claims are percentages of it.

Extension of time

A variation can carry an Extension of time (days). Adding work usually adds programme, and if you do not claim the time when you claim the money, you have accepted the original completion date for a larger scope.

That is how builders end up in liquidated damages on a job they were never late on.

In this section

• Creating a variation
• Getting client approval
• How variations affect the job
• The variations list