Remeasurement contract: quantity changes, preliminaries and provisional sums
A building is let on a remeasurement contract using a bill of quantities. The bill includes 1,200 m³ of excavation, 850 m² of paving, 60 m of kerb, a €45,000 provisional sum for ground investigation, a €18,000 prime cost sum for electrical supply, and €220,000 of preliminaries for a 52-week programme. During the works the excavation is remeasured at 1,430 m³ and the paving at 780 m². The engineer omits the 60 m of kerb and instructs an additional 180 m² of paving and 40 m of kerb in a different location. A five-week delay is caused by late design information from the employer. The contractor claims the whole €220,000 preliminaries pro rata for five weeks, plus loss of productivity on the paving, and asks for the provisional sum and prime cost sum to be paid as lump sums.
1. Explain how the excavation, paving and kerb should be remeasured and valued, including the effect of the omissions and additions.
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On a remeasurement contract the bill quantities are estimates, not fixed quantities. The excavation is remeasured at 1,430 m³, so the measured quantity is 1,430 m³, not 1,200 m³. The bill rate is used unless the change is so significant that the rate is no longer applicable; a change from 1,200 to 1,430 m³ is a 19.2% increase, which the QS should record and test against any rate-change clause, but it does not automatically create a new rate.
Paving: the original 850 m² is remeasured at 780 m², an omission of 70 m². The instructed addition is 180 m², so the net measured paving is 780 + 180 = 960 m². The addition is valued at the bill rate if the work is of similar character and conditions; otherwise a new rate is built.
Kerb: the 60 m is omitted, giving a credit. The instructed 40 m is an addition, but because it is in a different location the QS must check whether the bill rate still applies. If the kerb type, bedding and excavation are the same, the bill rate can be used; if not, a new rate is required. The net measured kerb is 40 m, not 60 m plus 40 m.
2. Assess the contractor’s preliminaries claim and explain the correct approach to the five-week delay.
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The claim should not be paid as 5/52 of €220,000 without analysis. Preliminaries are not all time-related. Some are fixed or lump-sum items (site establishment, temporary offices, insurance, bonds), while others are time-related (site management, supervision, scaffolding, temporary services, plant standing). The QS should split the €220,000 into fixed and time-related portions and apply the five-week delay only to the time-related portion, unless the contract expressly allows a different adjustment. If, for example, €130,000 is time-related, the pro-rata figure would be €130,000 × 5/52 = €12,500, not €21,154.
The delay must also be attributed. Late design information from the employer is normally an employer risk, so the contractor may be entitled to time and, if the contract provides, prolongation costs. The contractor must demonstrate that the five weeks actually extended the time-related preliminaries and that the costs were incurred; a delay to the completion date does not automatically prove every preliminary cost. Loss of productivity on paving is a separate claim and must be evidenced, not assumed from the delay.
3. How should the provisional sum and prime cost sum be dealt with, and what records should the QS require?
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Neither sum is paid as a lump sum merely because it appears in the bill. The €45,000 ground investigation provisional sum is an allowance for work that may or may not be instructed. The QS should adjust it to the actual instructed work, valued under the contract, and omit any unused balance. If the work was not instructed, the contractor receives nothing for it.
The €18,000 electrical supply prime cost sum is an allowance for a named supplier or specified supply. The QS should adjust it to the actual invoice or payment, then add the contractor’s handling, profit or attendance only as the contract permits. The contractor must produce invoices, delivery notes and measurement records. The QS should require records of the instructed ground investigation, the actual electrical supply cost, and evidence that neither sum has been used for work already covered by the measured items.