Contract Sum

A developer signs a building contract with a stated sum of $25 million, which is the starting price for the described work, not a guarantee that the final project cost will be exactly $25 million. First inspect the scope and pricing documents, since the sum may be supported by a bill of quantities, activity schedule or lump-sum breakdown.

Check whether taxes, contingency, design fees and owner-supplied items are included, because a project budget may cover land, professional fees and finance costs that are not in the builder's contract sum. A variation is a change to the agreed work, and its effect on price depends on the contract's procedure and valuation rules.

A provisional sum allows for work not fully defined when the contract is signed, and its later treatment depends on the document: the allowance may be replaced by assessed work or adjusted under a specified process. Some contracts have price-fluctuation provisions tied to materials or labour, while others put more price risk on the contractor.

Progress payments are not the same as the final contract value, because interim certificates or valuations determine amounts due during performance under the agreed mechanism. Maintain a change log that begins with the original sum and records approved changes, pending requests, provisional adjustments, known claims and forecast final cost separately.

RICS guidance on commercial management of construction covers monitoring cost and financial performance through the life of a project, and its final-account procedures stress change control and the link from the latest cost report to final account; those sources are UK practice information, so local contracts and rules still control elsewhere. The final account is a reconciliation or determination of the amount due under the contract after applicable adjustments, and parties may disagree about measurement, variations, delay, defects or other claims before a figure is settled.

Use consistent labels in reports: original contract sum, current approved contract value, forecast final account and total project budget. Suppose the original sum is $25 million and approved changes add $1.5 million; if omissions and other net adjustments reduce the final account by $0.3 million, the result is $26.2 million, and the illustrative growth from the original sum is $1.2 million / $25 million, or 4.8%.

The owner may have ordered valuable extra space, or the original price may have excluded foreseeable work, so explain the scope and reasons behind the variance before judging performance. Control approvals before work changes where practical, defining who may authorise a variation and how its price and time effect is assessed, because verbal directions can produce disputes when records are incomplete even if work was actually performed.

Pay attention to timing too, since a price change can also alter completion dates, cash needs and financing, and keep contingency separate from the contract sum unless it is expressly part of the agreement, because owner contingency is a budget reserve and not an automatic entitlement for the contractor. For owners, the key question is not merely whether the final number exceeds the signed sum but which changes were instructed, which risks the contract allocates and which amounts remain disputed, which is a better basis for forecasting and negotiation.

When pricing approaches differ, such as a framework with call-off orders or a cost-reimbursable arrangement, there may be an estimate or cap rather than a single all-in fixed figure, so state the pricing model instead of forcing one definition. Later warranty claims or audits may require the history, and a clean trail also improves the next project's estimate and change process.