A variation order is a change, often in construction, that modifies all or part of an existing order. Many construction projects undergo changes, especially after the beginning of building, and the cost impact on a construction project with a variation order can be costly.
A variation order may simply be an addition to an existing order, or it may replace the order entirely. Other variations may include alterations to design, alteration to quantity, modification in sequencing of work, quality alterations and working condition alterations. Variation orders affect not only the cost o the project, and may affect completion dates as well.