1. The plaintiff's claim is dismissed.

2. The costs of lawsuit shall be borne by the Plaintiff.

Facts of recognition

On August 13, 2015, Plaintiff (hereinafter “Co., Ltd. B”), C, D, and limited partnership companies constituted a joint contractor with the representative of Plaintiff as its representative.

On May 9, 2014, the Plaintiff, as a representative member of the said joint supply and demand company, was awarded a contract with the Defendant for construction works for the F facilities (hereinafter “new construction works in this case”) at KRW 26,706,223,000 for the total construction cost.

On March 21, 2016, the Plaintiff entered into a contract with the Defendant to change the construction cost of the instant newly-built construction to KRW 26,939,527,932. On July 14, 2016, the Plaintiff entered into a contract to change the total construction cost of the instant newly-built construction to KRW 28,654,458,940.

Since then, the above joint contractors, including the plaintiff, completed the new construction of this case, and the defendant paid all the construction cost under the new construction contract of this case under the above modified contract.

[Reasons for Recognition] A, Evidence Nos. 1, 2, Evidence Nos. 1, 10, 11 (including additional numbers), and the Plaintiff’s assertion of the purport of the entire pleadings was made to perform the new construction works of this case by adding or modifying the following contents in the course of the construction works of this case:

Accordingly, the plaintiff filed an application for adjustment of the contract amount with the defendant pursuant to Articles 19 and 20 of the General Conditions of the Construction Contract in this case through the responsible supervisor, but the defendant rejected it and did not comply with the consultation without reasonable grounds.

Therefore, the defendant shall pay the following amount as additional construction cost to the plaintiff:

Even if a responsible supervisor has no authority to act for the defendant, the defendant is responsible for acting as an expression agent under Article 125 of the Civil Act, since the defendant managed and supervised the new construction of this case through the responsible supervisor, and received the delivery of the documents, etc.

In addition, the defendant has been continuously reported by the plaintiff on the change of the design, and accordingly, the defendant is about the change of the design.