1. The Plaintiff (Counterclaim Defendant) paid KRW 64,064,630 to the Defendant (Counterclaim Plaintiff) and its related amount from November 29, 2017 to February 6, 2018.

1. Basic facts

A. On February 4, 2014, the Plaintiff concluded a contract with the Defendant for the construction period of “the instant construction works” (hereinafter “the instant construction works”) from February 20, 2014 to August 31, 2014 (hereinafter “the instant construction contract”). The Plaintiff subcontracted the title of the instant construction works, and the glass Corporation subcontracted the instant construction works to D.

B. The Plaintiff completed the instant construction, and the approval for use of the instant building was also granted.

[Ground of recognition] A without dispute, entry of evidence No. 1, purport of the whole pleadings

2. Determination on the main claim

A. The plaintiff's assertion 1) First of all, the defendant is obligated to pay to the plaintiff only KRW 227.5 million out of the construction cost of this case 265 million and the remainder of the construction cost of this case 37.5 million, on the ground that the defendant did not pay the plaintiff KRW 37.5 million.

Next, the defendant is obligated to pay 9 million won to the plaintiff additional construction costs incurred by the alteration and construction of the windows of each entrance of the suspender and boiler room.

In addition, the defendant is obligated to pay to the plaintiff 1,134,00 won [2,130,000 won = 210,00 won [2,00 won = 120,00 won - 120,000 won) x 54 square meters] of the additional construction cost arising from the alteration and construction of the floor that was built as a material of KRW 1,20,00 per square meter unit price at the defendant's request by the defendant.

Ultimately, the Defendant is obligated to pay to the Plaintiff KRW 5,784,00 (=amount of KRW 37,500,000 + KRW 9 million for additional construction works related to the change of windows + KRW 1,134,00 for additional construction works related to the change of the floor) and damages for delay.

B) The summary of the Defendant’s assertion was that the Defendant paid KRW 261.5 million to the Plaintiff as the construction cost, and thus, the Defendant is obligated to pay only KRW 3.5 million to the remainder of the construction work (=265 million - KRW 265 billion - KRW 1.5 million 5 million.

On the other hand.