Change control

A variation that survives being challenged

Recording the amount is the easy half. What matters two years later is which rule you valued it under, who instructed it, and whether it has already been paid.

Basis of valuation from the RICS hierarchy, contract rates through to lump sum quotation
Contract clause, so the route is on the record
Extension of time in days and whether loss and expense applies

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Variations

VO-01 Additional window to gable

Basis of valuationContract rates

Contract clauseJCT 5.6.1

Extension of time2 days

Loss and expenseNo

Instructed byR. Hall, architect

Subtotal£1,000.00

Certified in valuations£1,000.00

Still to certify£0.00

That is the part you are asked for when the final account is disputed, and it is the part that is always missing.

The reasoning, not just the number

A spreadsheet records that a variation was worth one thousand pounds.

It does not record that you valued it at contract rates under clause 5.6.1, that it carried two days of extension of time, and that loss and expense was not claimed. That is the part you are asked for when the final account is disputed, and it is the part that is always missing.

Client Valuations

Approved variations become valuation lines

Under JCT a variation is valued in the periodic valuation, not paid separately on the side.

Retention is deducted once, in the certificate, exactly as JCT expects
The variation shows its own certified percentage on the variation record
A certified variation cannot also be marked Paid, so nothing counts twice

Client Valuations

Adding variations to PC-04

RefValueThis period

VO-01 Additional window£1,000£1,000.00

VO-03 Revised M&E layout£3,240£1,620.00

Retention deducted on variations(£131.00)

Counted twice?Guarded

Add Variations pulls every approved variation into the certificate as a normal line, so retention, progress and the statutory dates run down one track.

Client Valuations

Where an approved variation is actually certified

VO-01 is worth £1,000, but it is not money until it is certified, and under JCT it is certified inside the valuation, not on a separate note.

Approved variations pull in as valuation lines
Retention deducted once, in the certificate
Certified percentage written back to the variation record

Client Valuations

Adding variations to PC-04

RefValueThis period

VO-01 Additional window£1,000£1,000.00

VO-03 Revised M&E layout£3,240£1,620.00

Variations this period£2,620.00

Less retention at 5%(£131.00)

Add Variations pulls VO-01 and VO-03 into the certificate as lines, so retention is deducted once and the certified percentage is written back to the variation record.

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Final account

Every variation lands in the adjusted contract sum

A variation that is approved but never carried into the final account is money left on the table.

Approved variations added to the contract sum
Omissions carried through as negative figures
Provisional sums adjusted against what the work actually cost

Final account

Statement, 11 Essex Road

Original contract sum£219,250.33

Variations, approved+£1,000.00

Provisional sums adjusted(£2,400.00)

Adjusted contract sum£217,850.33

QScope rolls the approved variations into the adjusted contract sum automatically, so VO-01 and the rest are in the account without being re-keyed.

Instructions

No instruction behind it, no variation

The first thing a payer refuses is a variation with no instruction to authorise it.

Each variation linked to its authorising instruction, both ways
Instructions with a cost effect and no variation, shown in red
Verbal instructions awaiting written confirmation, shown in amber

Instructions

AI-006 · Additional windowVariation VO-01

AI-019 · Additional drainageNo variation raised

CVI-004 · Verbal, 12 MayAwaiting confirmation

With a cost effect19 of 24

AI-019 changes the cost of the works and has no variation against it. As things stand it will not reach the final account.

Variations

On FIDIC the Engineer instructs and Clause 12 values

The chain is not identical outside the UK.

Engineer’s instruction under Clause 13, Variation Procedure 13.3
Measured work valued under Clause 12, daywork under 13.6
The jurisdiction banner reminds you the country figures are starting points to verify locally

Variations

VO-07 Additional piling, FIDIC Red Book

Instructed byEngineer, Clause 13

Variation procedure13.3

Basis of valuationMeasured, Clause 12

Daywork13.6, not applied

Subtotal£84,000.00

Valued in Statement£84,000.00

Still to certify£0.00

QScope holds the same fields whichever form you are on: who instructed it, the clause it rests on, and the basis of valuation. Set the contract to FIDIC and the clause references and currency follow, and the approved variation is carried into the Statement rather than a JCT valuation.

Who it is for

One change, four people it touches

You are applying

You price the change and defend it

You price the instruction, submit the variation and defend it when it comes back cut. Instructed work with no variation against it is money you have already spent.

Applying for payment

the same measurement

You are certifying

You value the change and answer for it

You value the variation from the other chair and account for what you cut. The register you keep is the one the final account will be argued from.

Certifying payment

You are doing both

You build the change, paid or not

You absorb the small changes as they come, and the ones nobody wrote down are the ones you end up building for free.

Doing both yourself

You are reporting

You fund the change, priced or blind

You check that scope changes are priced and approved before money moves, because an unpriced variation is risk the facility is carrying blind.

Recommending a drawdown

The client, the architect and the tenderer are not on this list. They are the people you let in on a link: they see the one document you sent them, answer it, and that answer is written into the record. No account, no licence, no charge, on every plan.

FAQs

The questions this page raises most often, answered without a sales pitch at the end.

Yes, if that is what your contract does. Mark it Paid on the variation itself. If you later certify the same variation inside a valuation, QScope stops it counting twice rather than trusting you to remember.

Yes. A variation can be an addition, an omission or a substitution, and omissions carry through to the adjusted contract sum and the final account as negative figures.

It follows your contract. If a variation is certified inside a valuation, retention is deducted there once. If it is paid separately, you can set a retention rate on the variation itself, including zero for loss and expense which is normally not subject to retention.

Yes. Each variation prints on your letterhead with the description, the reason, the basis of valuation and the amount, ready to be issued as a confirmation of instruction.

The fields are the same. The Engineer instructs the Variation under Clause 13, the Variation Procedure runs under 13.3, measured work is valued under Clause 12 and daywork under 13.6. Set the contract form to FIDIC and the clause references and currency follow, and the approved variation is carried into the Statement rather than a JCT valuation.

From the blog

The part nobody teaches you, written down

Three pieces from the same corner of a contract as this page, answered at length and without a sales pitch at the end.

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How do you price extra work so the client actually pays for it?

Instruction first, then the valuation ladder your contract sets: contract rates, adjusted rates, a fair price or dayworks. Where each rung applies, and why the smallest variations are the ones that never get paid.

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Variations15/07/2026

Small extras keep eating the job. How do I stop doing them for free?

No single extra under two hundred pounds feels worth the awkward conversation, and thirty of them are a month’s wages. The three-sentence habit that captures small changes without souring the job, and the quote clause that makes the habit expected.

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Variations11/06/2026

Loss and expense is not the same as an extension of time

Time and money are separate entitlements with separate tests. Why an extension of time does not carry money with it, what has to be ascertained, and where these claims usually fail.

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All 174 pieces

Keep reading

The three parts this page leans on

Valuations and certificates Interim valuations and payment certificates by percentage or fixed sum, with retention and previously certified. UK JCT and NEC, plus FIDIC certificates. See how it works Final account From the adjusted contract sum to the final balance under JCT, or the FIDIC Final Statement and Final Payment Certificate, every adjustment on its own line. See how it works Risk register Record commercial risks with a probability and a cost. The allowance is the expected value, ready to carry into the cost report as a contingency you can defend. See how it works