Joint measurement
The VOB/B provides that the work is established jointly by client and contractor so far as possible. Joint measurement carries considerable evidential weight and is therefore more than a courtesy.
The reason is evidential. Joint measurement is a shared finding: both sides have seen and confirmed the quantities. Whoever later relies on differing quantities bears the burden of proof, and that burden is hard to discharge once the element is concealed or built over.
A rule follows that prevents most disputes over final accounts: what will no longer be visible is measured jointly before it is closed up. Backfilled excavations, concealed services and closed constructions cannot be measured afterwards, only reconstructed.
Where joint measurement does not happen, one's own measurement should be recorded so that it remains traceable. That means date, location, sketches and photographs.
The verifiable invoice
The invoice must be verifiable. That means the client must be able to follow it without conducting enquiries of their own.
The content follows from that standard:
| Entry | Function |
|---|---|
| Reference to the items of the bill of quantities | allocation to the contract |
| Item numbers unchanged | traceability of origin |
| Quantities with measurement evidence | substantiation of the work |
| Unit rates from the contract | correspondence with the tender |
| Variations shown separately | separation from the main contract |
| Interim payments deducted | establishing the balance |
| Value added tax | on the total |
The second row deserves attention. The item numbers carry the whole chain from bill of quantities through tender and order to final account. Changing them along the way breaks the allocation, and verifiability suffers directly.
The requirements for a verifiable invoice resemble those for the designer's final fee account but follow their own rules. The comparison is instructive: in both cases verifiability governs when the claim falls due, not its amount.
Handover precedes falling due
The claim to payment does not fall due on the invoice alone. Two conditions are required: handover of the works and delivery of a verifiable final account.
Where either is absent, the claim exists but cannot be enforced. For the contractor that means actively pursuing handover rather than waiting for it. The article on handover covers the routes.
Where the VOB/B ends and the VOB/C begins
This is the most important point of this article and the commonest source of error when checking invoices. It concerns which rule determines the quantity.
| Part | Governs | Content |
|---|---|---|
| The VOB/B | the procedure | who establishes, when, in what form and with what consequences |
| The VOB/C | the method | how measurement proceeds, in what unit, what is measured over and what is deducted |
An account complying with the VOB/B procedure but disregarding the measurement rules of the VOB/C is formally in order and substantively wrong. The reverse case is equally common.
A fixed sequence follows for checking an invoice. It begins with the trade and ends with the general rule.
- Is the invoice verifiable, that is traceably built and supported by measurement evidence.
- Are the quantities correctly established, under the rules of the relevant ATV.
- Are the prices contractual, including variations.
The second step presupposes that the right ATV is consulted and that the right deduction rules within it are applied. The article on the deduction rules covers them in detail.
What to watch on variations
Variations belong shown separately in the final account and not folded into the items of the main contract. Otherwise the account is not verifiable and does not fall due.
The reason is practical: the client must be able to see which amount falls on the original contract and which on later orders. Mixing them makes the account assailable and complicates any check.
Each variation needs the particulars supporting its justification: the order, where applicable the notice, and the derivation of the price. The article on variations covers the conditions.
The transition to the final cost statement
For the designer, settling the construction contracts also closes cost planning. The final cost statement under the cost planning standard rests on the contractors' final accounts.
Two points bear noting.
| Finding | What follows |
|---|---|
| The orderings differ | final accounts follow the procurement packages, the final cost statement the cost groups; without a mapping carried alongside, the reconciliation is hard to reconstruct afterwards |
| The final cost statement is the only source of in-house benchmarks | it is also the last opportunity to secure a project's data for future cost work |
What to record
Four precautions secure the settlement of a project. All of them take effect during construction rather than at the final account.
- Measurements before closing up, jointly where possible, recorded where not.
- Stable item numbers across the whole project.
- Variations with full derivation, kept separate.
- The mapping to cost groups, carried alongside rather than reconstructed afterwards.
The first is the most important and the least laborious. A measurement taken at the right moment costs minutes; reconstructing it afterwards costs expert reports.
Related articles
This article reflects the position of the rules at the date of checking and serves professional orientation. It does not constitute legal advice and does not replace assessment of the individual case.