Variation, conditions precedent and waiver

The Privy Council in Uniform Building Contractors Ltd v The Water and Sewerage Authority of Trinidad and Tobago [2026] UKPC 2 held that four items relied upon by a contractor as variations were not variations to the employer's requirements or to the works so that the contractor was not entitled to additional payment for these items. The question whether or not there has been such a variation has to be answered by reference to the terms of the contract between the parties. The contract in the present case was a lump sum contract and the comprehensive obligations undertaken by the contractor were such that the additional items could not be regarded as variations. Further, it was held that the contractor had not complied with a condition precedent to any entitlement to claim additional payment and that it was not entitled to rely on waiver, estoppel or a broad notion of fairness in order to obtain payment for the additional work it claimed it had carried out. The central lesson that emerges from the decision is the importance of paying careful attention to the terms of the contract when seeking to ascertain the rights and obligations of the parties to that contract.