What is a common cause of a constructive change?

A constructive change occurs when a party's actions or inactions lead to a variation from the original contract, even if no formal amendment has been made. This typically happens without an official change order, and it generally results from circumstances that compel a change in the way work is carried out under the contract.

Common causes of constructive changes include changes in project scope, which can arise from various factors such as evolving project needs or stakeholder input that necessitates modifications. Additionally, contractor performance issues may contribute to constructive changes if the contractor's inability to meet specifications leads to rework or adjustment of the original terms. Similarly, changes in requirements or specifications, whether due to regulatory updates or internal decision-making, can also trigger a constructive change.

Since each of these situations can independently lead to variations in the execution of a contract, having all of these causes recognized as valid instances of constructive changes is accurate. Thus, all these answers are correct, collectively illustrating the multifaceted nature of potential contract changes that do not arise from formal modifications.