The article attempts to distinguish between additional work under a construction contract provided for in Article 743 of the Civil Code of the Russian Federation and other work that was not initially agreed upon by the parties. Such works can be performed by a contractor and are independent. Based on the Civil Code of the Russian Federation, judicial practice and special literature, an approach to the differentiation of such works is proposed. This approach is based on the author's classification of types of additional work (ordinary and extraordinary). The author argues that the extraordinary nature of the works precludes the possibility of recognizing such works as independent. Independent works should be recognized as follows: works whose types or volumes are not provided for in the contract; the obligation to perform them does not arise from the terms of the contract; the performance of such works does not technologically depend on the fulfillment of obligations under the original contract.