What is a variation on a construction project?
What is a variation on a construction project?

The following Construction guidance note provides comprehensive and up to date legal information covering:

  • What is a variation on a construction project?
  • Why do we need variation provisions?
  • Why do variations arise?
  • Types of variation and standard forms
  • What does and does not constitute a variation
  • A variation cannot change the fundamental nature of the works
  • Omissions

A variation (sometimes referred to as a change) is an alteration to the scope of work originally specified in the contract, whether by way of an addition, omission, or substitution to the works, or through a change to the manner in which the works are to be carried out.

The particular nature of the construction process makes the subject of variations an important one. Inevitably, because the parties are unable to anticipate everything which may happen or where a contract is agreed before the design or scope of works are fully finalised, frequent changes are often required. Unless a variation is instructed, a contractor is required to follow the works as originally specified—otherwise it would be in breach of contract.

When the employer asks the contractor to vary the work, the variation is being made under the contract rather than to the contract itself. For guidance on changes to the terms of the contract itself, see Practice Note: When is variation of a contract valid?

The contractual requirements relating to instruction of variations are covered in Practice Note: Variation instructions on a construction project, which considers procedural requirements for instructions, including written and oral orders, the duty to order a variation (where an employer has failed to do so), circumstances in which a contractor may recover payment for changed works in the absence of