The libretto delle misure and the registro di contabilità

Annex II.14 to the public contracts code places on the direttore dei lavori, the works supervisor, the control of expenditure through the accurate and timely completion of the accounting documents, by which expenditure generating events are established and recorded. The accounting documents are the instrument of that control.

The two qualifications in that wording carry distinct operational consequences. The status of public instrument means the entries carry evidential weight and that altering them has significance beyond the contractual sphere. The requirement of timeliness means the entry must be made when the event occurs, not reconstructed afterwards as an interim valuation approaches.

Record	Content	Function
Giornale dei lavori	Chronological record of site activity: personnel, plant, weather, instructions received, significant events	Reconstruct the history of execution
Libretto delle misure	Measurements of work executed and supplies delivered, with the dimensions recorded	Establish the quantities
Registro di contabilità and summary	Quantities valued at contract rates, with cumulative progression	Convert quantities into amounts
Stato di avanzamento lavori	Cumulative summary for the purposes of an instalment	Determine the payment
Certificato di pagamento	Instrument of the project officer releasing the instalment	Authorise the payment order
Conto finale dei lavori	Closure of the contract accounts	Consolidate the final position

The sequence is rigid. The measurement book feeds the register, the register feeds the interim valuation, the interim valuation supports the payment certificate. Skipping a step does not speed the process up: it removes its foundation.

This is the record in which establishment materially takes place. Measurements must be entered in the form in which they were taken, with dimensions and the number of elements, so that the final figure is the result of a verifiable calculation rather than a declared value.

Two needs coexist and must both be met. The first is traceability against the design: every measurement must be referable to an item in the schedule of rates and to an identifiable part of the works. The second is traceability against the site: work destined to be concealed by later stages must be measured before that happens, because afterwards verification is impossible.

This second need is why timeliness is not a formal requirement. A measurement not taken at the right moment cannot be recovered, and reconstructing it afterwards is precisely what generates dispute.

The register converts measurements into amounts by applying the contract rates, meaning the net unit rates from the schedule attached to the contract reduced by the discount offered at tender. The summary provides the aggregated reading.

The register is also the record on which the contractor's signature is taken, and from this derives its function as the forum for the contradictory process. It contains more than figures: it contains the moment at which the contractor takes a position on those figures.

One limit on valuation should be known. Work whose satisfactory execution requires certificates or checks not yet obtained cannot be treated as usefully executed, and therefore cannot be valued and entered in the register. This constraint affects payment timing and should be anticipated when programming tests and partial inspections.

Construction accounting is now largely kept using information systems, and the transition has changed the form of the records without changing their nature. The evidential nature of the documents is nonetheless unchanged.

Two implications warrant attention. The first concerns signature: a register kept in digital form requires signing arrangements ensuring the attribution and reliable dating of entries, and it is the signature, not the medium, that underpins the regime governing reservations. The second concerns immutability: the timeliness and non alterability of entries, which on paper were secured by the physical nature of the document, require equivalent safeguards in digital form.

The code also provides for the adoption of digital information management methods and tools for the design and delivery of projects above a given value threshold. Where these are used, the works supervisor ensures the correlation between the accounting records and the information models produced or updated during construction.

The practical consequence for whoever prepared the bill is a demand for structural consistency. If the design quantities were extracted from a model and the accounts correlate to that model, the structure of the items and their correspondence with the parts of the works must be settled once and settled stably, because every divergence between the structure of the bill and that of the accounts is paid for at every interim valuation.

The regime governing reservations is the principal reason why the quality of record keeping has defensive value for both parties. A poorly kept register weakens whoever prepares it and whoever signs it.

Reservations must be entered in the registro di contabilità on the signature immediately following the occurrence or cessation of the prejudicial event, failing which they lapse, and must also be entered on signing the final inspection certificate through precise articulation of the objections relating to those operations. The time limit is strict and the forfeiture operates automatically.

They must be framed specifically and state precisely the grounds on which they rest, and must contain, failing which they are inadmissible, the precise quantification of the sums the contractor considers due. The quantification must be given, failing which they are inadmissible.

Reservations not expressly confirmed on the final account are treated as waived. Signing the final account is therefore a decisive step and not a closing formality.

On certification of completion the works supervisor delivers to the project officer a report describing the events of the construction period, and prepares the conto finale dei lavori, which must be signed by the contractor. The report also states a position on the reservations.

The final account consolidates the accounts and opens the stage of final verification of the works, whose outcome attests the conformity of what has been built and leads to release of the balance and of the securities. The outcome attests the conformity of what has been built.

Deferred completion is the first and the most serious. A measurement book reconstructed weeks later loses the ability to establish concealed work and turns establishment into estimation.

A measurement entered as an aggregate figure without the calculation is the second, and deprives the record of the verifiability that is its purpose. The record loses the verifiability that is its purpose.

Applying design rates rather than the discounted contract rates is the third, and produces systematically overstated amounts that surface at the first check. The amounts come out systematically overstated.

Obtaining a signature without drawing the contractor's attention to the contestable entries is the fourth. Formally regular, it invites challenge to the genuineness of the contradictory process.

The regime of Annex II.14 does not apply to private work, and in practice accounting is often replaced by an exchange of invoices and progress statements drawn up by the contractor. The evidential value is lost with it.

Even a simplified measurement book, shared and signed periodically, changes the nature of the relationship. It shifts the argument from what the parties assert to what was measured together, and in particular makes verifiable the work destined to be covered over, which is where private disputes concentrate.