A. On May 21, 2014, C University entered into a contract for construction works with D Co., Ltd. (hereinafter “D”) under which construction costs of KRW 5.39 billion and construction period from June 30, 2014 to June 30, 2016 (hereinafter “instant building”) entered into a contract for construction works and civil engineering works with D Co., Ltd. (hereinafter “D”).

B. On August 25, 2014, D entered into a subcontract agreement between the Defendant and the Defendant regarding the construction cost of KRW 475 million and the construction period from September 17, 2014 to April 30, 2016 with the effect that the subcontract for the construction works of the instant building was made.

C. On June 25, 2015, the Defendant entered into a contract with the Plaintiff on the payment of heating and cooling products and construction of the instant building (hereinafter “instant heating and cooling construction”) with the amount of construction KRW 92.5 million. D.

D, the Plaintiff, and the Defendant stated the date of preparation in the instant agreement on March 7, 2017, but considering the facsimile numbers of Gap evidence No. 9 in light of the Fax numbers of Gap evidence No. 9 on March 7, 2017, it is reasonable to view the date of final agreement as March 7, 2017.

By March 15, 2017, the Defendant terminated the supply of equipment and trial operation, and the Plaintiff drafted a confirmation agreement (hereinafter “instant agreement”) stating that the Defendant will pay the Defendant the unpaid construction cost of KRW 87,50,000 to the Defendant on March 30, 2017.

[Recognition] Facts without dispute, Gap evidence 2 and 9 (including each number, hereinafter the same shall apply), Eul evidence 2 and 4, the purport of the whole pleadings

2. The parties' assertion

A. Although the Plaintiff’s assertion completed the heating and cooling construction of this case, the Defendant paid 1.5 million won out of the construction cost of KRW 1992.5 million and did not pay the remainder construction cost of KRW 87.5 million.

B. The Defendant did not properly observe the construction period promised by the Plaintiff, and the Defendant did not receive construction cost of KRW 217 million from the original contractor D.