1. The Defendant: (a) Plaintiff A Co., Ltd.; (b) KRW 827,118,329; (c) KRW 556,179,471; and (d) Plaintiff C.

1. Basic facts

A. The Plaintiffs organized a joint contractors (investment ratio: A 41.64%, B 28%, C9%, D8.18%, E8.18%, and F 5%) as the representative of the Plaintiff A to execute the G Facility construction ordered by the Defendant (hereinafter “instant construction”).

B. On November 26, 2014, the Plaintiffs entered into a contract for construction works in the form of a long-term contract (hereinafter “instant contract for construction works”) with the Defendant, setting the contract amount of KRW 7,178,29,970, total construction amount of KRW 258,871,836,00, and the contract period of the construction works from November 26, 2014 to December 31, 2016.

(hereinafter referred to as the “general contract” and the “number of borrowed-water contracts” are divided into the instant contract and the overall contract for the instant contract.

(1) Article 20 (Adjustment of Contract Price due to Modification of Design) of the General Conditions of Construction Contract applicable to the instant construction contract (hereinafter “the instant general conditions”) and Article 20 (Adjustment of Contract Price due to Modification of Design) of the General Conditions of Construction Contract, which applies to the instant construction contract, shall file an application for the adjustment of the contract price before the completion date under the former part of paragraph (8) is received by the contractor (in

Article 23 (Adjustment of Contract Amount Due to Amendment to Terms and Conditions of Contract) (1) In cases where it is necessary to adjust the contract amount due to a change in the terms and conditions of contract, such as a change in the distance of transportation for a construction period, in addition to cases prescribed in Articles 20 and 22 in a construction contract, the public official in charge of contracts shall adjust it to the extent that it does not exceed the actual expenses according to the changed terms and conditions, and Chapter XIV (Calculation of Actual

(2) When the contract price is increased pursuant to paragraph (1), it shall be adjusted upon request of the other party to the contract.

(4) Article 20 (8) through (10) shall apply mutatis mutandis to the adjustment of contract price under paragraphs (1) through (4).

The main contents are as follows.