1. The Defendant (Counterclaim Plaintiff) paid KRW 426,676,867 to the Plaintiff (Counterclaim Defendant) and its amount from November 26, 2016 to December 12, 2018.

1. Basic facts

A. On October 1, 2015, the Plaintiff received a contract from the Defendant from Nonparty C Co., Ltd. (hereinafter referred to as “C”) for the installation period of construction of D D D D D D D D D D D D D D D D D D D D D D D D D D D D joint installation works (hereinafter “instant site”) from October 1, 2015 to July 31, 2016, respectively, with the construction period of KRW 1,782,00,000 (the supply price of KRW 1,620,00,000, value-added tax of KRW 162,000,000,000 (the supply price of KRW 1,620,000,000), and the delay penalty rate of KRW 3/100 (day).

B. The Plaintiff completed the instant construction around October 31, 2016.

[Ground of recognition] Unsatisfy, entry of Gap evidence 1, purport of whole pleadings

2. Determination as to the claim on the principal lawsuit

A. The summary of the Plaintiff’s claim 1) Although the Plaintiff completed the instant construction work, the Defendant did not pay KRW 40,700,000 among the construction cost of the instant case, and thus, the Defendant shall pay the said KRW 40,700,000 and damages for delay thereof. 2) The Plaintiff, upon the Defendant’s design change and demand for additional construction work, performed an additional construction work other than the construction work under the instant construction contract, and the construction cost of the additional construction portion is KRW 740,000.

Therefore, the defendant should pay the plaintiff the above additional construction cost of KRW 740,000,000 and damages for delay.

B. On October 1, 2015, with respect to the claim for the payment of the construction cost unpaid, the Plaintiff was awarded a subcontract for the instant construction cost of KRW 1,782,00,000 and completed the said construction work on or around October 31, 2016, as seen earlier. Since there is no dispute between the parties that the Defendant paid to the Plaintiff KRW 40,700,000 out of the instant construction cost, the Defendant is liable to pay the Plaintiff the unpaid construction cost of KRW 40,700,000 and the delay damages therefrom, barring any special circumstance. 2) The Plaintiff’s assertion (1) as to the Plaintiff’s claim for the payment of additional construction cost of KRW 1,782,00,00 in accordance with the instant construction contract.