A variation is value you have already earned
On a PAM contract, instructed change is measured and priced like any other work. The mistake is treating variations as a final account problem when they are a monthly payment claim problem.
QScope Team · 8 March 2026 · 6 min read
A variation is work the contractor has been instructed to do that differs from the original scope. On a PAM standard form the architect issues the instruction, the quantity surveyor values it, and the value belongs in the payment cycle from the moment the work is done. CIPAA 2012 protects the right to progress payment for that work in the same way it protects the measured works, so there is no reason to park variations for the final account.
The valuation hierarchy
Instructed change is not priced by negotiation from a blank sheet. It is valued against the contract, in a settled order.
- Contract rates. Where the varied work is of similar character and executed under similar conditions, the bill rates apply directly.
- Adjusted rates. Where the character or conditions differ, the bill rate is the base and is adjusted to reflect the change.
- Fair rates. Where nothing in the bills is a fair basis, a fair valuation is built from first principles.
- Daywork. Where the work cannot be measured, it is valued on recorded time and materials.
Working down that order in sequence is what keeps a variation account defensible. Jumping to a fair rate when a bill rate fits is the fastest way to have the whole valuation reopened.
Get it into the payment claim
Every valued variation goes into the next payment claim as its own line, not buried in a movement on the measured works. Itemising it means the payer can see what changed, admit what is not in dispute inside the ten working day response window, and question only what is genuinely open. That is the difference between change that gets paid month on month and change that snowballs into a lump the payer refuses on sight.
Records are the valuation
The instruction, the measured quantities, the rate build up and, for daywork, the signed time and material sheets are the valuation. Without them a fair rate is just an assertion, and daywork with no signed sheets is close to unrecoverable. Keep the paper as the work happens, because a variation is only worth what you can show.
Value instructed change against the contract, in order, and carry it into the claim while the work is still visible. That is how variations stay cash flow and never become a final account fight.
QScope prices each variation against the contract rates and carries it straight into the interim payment claim, so instructed change is paid as it is done.