A. On September 13, 2013, the Defendant concluded a contract with respect to the new construction of the instant building (hereinafter “new construction of the instant building”) and C (hereinafter “new construction of the instant building”) by setting the contract amount of KRW 14,700,000,000 and the construction period from September 13, 2013 to May 10, 2014.

B. On October 25, 2013, the Defendant prepared a subcontract agreement with D Co., Ltd. (hereinafter “D”) and the incidental civil works among the new construction works of the instant building (hereinafter “instant construction”), but the actual construction works completed all of the instant construction works around May 2014 by the Plaintiff.

C. The Plaintiff received KRW 466,270,000 as the construction price of the instant case from the Defendant and D.

[Ground of recognition] Facts without dispute, Gap evidence No. 1, Eul evidence No. 1, Eul evidence No. 1, fact-finding results of this court's fact-finding, the purport of the whole pleadings

2. The Plaintiff’s assertion was awarded a contract on the premise that the construction site of the instant case was conducted by the Defendant upon subcontracting the instant construction project from the Defendant, but the construction cost was actually increased due to changes in design, etc.

Therefore, the Defendant is obligated to pay the Plaintiff the contract price of KRW 278,021,070 (=the contract price of KRW 486,982,550 for the additional construction work amount of KRW 231,101,520 - the contract price of KRW 440,063,00) and the delay damages.

3. Determination on contractor of the instant construction project

A. Comprehensively taking account of the details of evidence Nos. 12 and 15, and the fact-finding results of the fact-finding with respect to the goods transferred at the time of this court, the Defendant guaranteed the Plaintiff’s obligation to pay for the goods sold at the construction site of this case; the Defendant paid part of the construction cost of this case to the Plaintiff; and the Defendant issued a tax invoice on November 4, 2013.