1. All of the plaintiff's claims are dismissed.

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

1. Basic facts

A. On December 15, 2015, the Plaintiff awarded a contract for reinforced concrete construction works on the Osan City D site (hereinafter “Osan City”) ordered by C Co., Ltd. on December 15, 2015; the period of construction: From December 15, 2015 to August 31, 2016; the contract amount: 385,00,000 won; advance payment: 38,500,000 won; and progress payment: Cash payment within 15 days after receipt of progress payment from the ordering place once a month; 10% of the contract amount; 3.0% of the contract deposit; and 0.10% of the compensation for delay; and

On August 31, 2016, the Plaintiff and the Defendant changed the contract amount to 405,416,000 won, and the construction period from December 15, 2015 to February 28, 2017.

On October 27, 2016, the Plaintiff and the Defendant changed the contract amount to KRW 418,619,493 on the ground of the new item and the increase of indirect cost.

B. On February 17, 2016, among the F Business Facility Construction Works ordered by E (hereinafter “F site”), the Plaintiff subcontracted reinforced concrete construction works to the Defendant on February 17, 2016, and the construction period: From February 17, 2016 to August 31, 2016, contract amount: 583,00,000 won, and progress payment: Cash payment within 15 days after receipt of progress payment from the ordering authority once a month: 10% of the contract amount, 3.0% of the warranty bond, and 0.10% of the liquidated damages rate.

On August 31, 2016, the Plaintiff and the Defendant changed the contract amount to 609,109,105 won, and the construction period from February 17, 2016 to October 31, 2016, on the ground of additional theory due to the addition of underground floors, the addition of flats, and the addition of slves due to the slves cut.

On September 27, 2016, the Plaintiff and the Defendant changed the contract amount to KRW 631,580,400 on the grounds of the addition of the expenses for care work (on night work).

The Defendant, around September 20, 2016, stated that “Around September 20, 2016, the Plaintiff requested that the Plaintiff proceed with the supply and demand of, and construction of, the heat materials, since it is difficult to supply and demand materials any longer than the contract price, and the construction is also impossible.”