Is it actually a variation?

A variation is a change to the works that the contract empowers the employer or its agent to instruct, and for which the contract provides a valuation mechanism. Three elements: a change, an instruction with authority, and a route to value it.

Miss any one and the position becomes uncertain, which is where most variation disputes actually live.

What is not a variation

A clarification

An answer to a request for information that explains what the contract already required is not a change. The contractor has learned something; the scope has not moved.

The disagreement arises because the contractor's price may have assumed something cheaper. That is a tender risk question, not a variation question, and conflating the two produces a claim that fails on entitlement no matter how well the value is evidenced.

Correcting defective work

An instruction to put right work that does not comply is an instruction, but it is not a variation. It carries no additional payment.

A change to the contractor's method

Unless the contract specifies method, how the contractor builds it is generally its own affair. An instruction that constrains method may be a variation where the contract imposes restrictions on the manner in which the works are carried out; a preference expressed on site usually is not.

Something the contract already deals with elsewhere

Expenditure of a provisional sum, adjustment of a prime cost sum, and work covered by an approximate quantity all have their own mechanisms. Treating them as variations produces double counting at the final account.

What is a variation but does not look like one

• An omission. Removing work is a change, valued negatively. It requires an instruction like any other.
• A change in sequence or timing, where the contract treats restrictions on working hours, access or order of work as variations.
• A change to a provisional sum item where the work instructed differs from what the sum described.
• Acceptance of a substitution proposed by the contractor. Agreeing an alternative product is a change to the specification even where it was the contractor's idea.

Authority

The contract names who may instruct variations. It is generally the contract administrator, architect or project manager, not the client personally and not the clerk of works.

A client who tells the contractor on site to move a doorway has not instructed a variation. What follows is either a formal instruction confirming it, or an argument about whether the contractor was entitled to act on what it was told.

Verbal instructions

Most contracts require instructions in writing, and most provide a mechanism for confirming verbal ones: the contractor confirms in writing within a stated period, and the instruction takes effect unless dissented from within a further period.

That mechanism only works if someone uses it. In practice, work proceeds on the strength of a site conversation, nothing is confirmed, and the entitlement argument surfaces at the final account when the people involved remember it differently.

The habit worth building is simple: anything said on site that changes the works gets written down the same day, by whoever heard it, and sent to the other side. It does not need to be elegant. It needs to exist and to be dated.

Recording the decision, not just the number

When a variation is admitted, four things should be recorded together:

• What was instructed, and by whom
• The date of the instruction, and the date the work was carried out
• The valuation rule applied, and why
• Any effect on time, and whether loss and expense is claimed

Kept together, that record answers the entitlement question and the value question at once. Kept apart, in an instruction file, a valuation spreadsheet and an email chain, it answers neither reliably eighteen months later.

Which is the underlying point. Variations are rarely lost because the surveyor priced them badly. They are lost because nobody can now establish what was instructed, when, and by whom.