German Civil Construction contracts do not require them to follow the "The Construction Contract Procedures Part B (VOB/B)". The provisions of the German Civil Law are often not detailed enough. In the past, some civil construction contract often had controversial issues, and the contract articles were not standardized. It can only rely on the negotiation between the parties and the judgment of the court. There are a wide range of judgments covering this area, and lack of transparency. Considering the type of construction contract and the continuous development of construction technology, the content is complex and special, and the Construction contract often has a long period of performance. The accumulated judgment also makes the conditions of the new special legislation mature. The German Federal Parliament passed a bill to amend the Construction Contract Law in the Civil Code. The Construction contract (§§650 A-650O), the architect and engineer contract (§§650P-650T), and the consumer engineering contract (§§650U-650V) are included in the amendment. The motives for the change oders considered by the legis-lator in the amendment are cited as "complex construction contracts with longer performance periods", but in practice, it is not necessary to require the project contract implementation period to be longer or more complicated, and the change can be indicated.
黄立. 检视德国债编各论新修正工程合同规定的定作人变更权[J]. 北京航空航天大学学报（社会科学版）, 2019, 32(3): 7-15.
HUANG Li. Study on the principal's right to order changes in the construction plan in the New German Civil Code. JOURNAL OF BEIJING UNIVERSITY OF AERONAUTICS AND A, 2019, 32(3): 7-15.