The judgment of the first instance court is modified as follows.

Defendant (Counterclaim Plaintiff) is the 6,943,028 won and the 6,943,028 won.

1. The reasoning of the court of first instance is as follows: (a) the defective repair cost of KRW 29,368,390 in the nine-way decision of the court of first instance is dismissed as the cost of the defective repair cost of KRW 26,929,728 in the cost of the defect repair; and (b) the supplementary judgment is added following the nine-way decision, and thus, (c) the part of the judgment is cited in accordance with the main sentence of Article 420 of the Civil Procedure Act.

- Additional Decision - Judgment on the Defendant’s defense of offset

A. The defendant's defense of offset against the defendant has the claim in favor of the first instance court, and the service of the plaintiff's claim in favor of the plaintiff on October 8, 2020 of the plaintiff's claim in favor of the lawsuit shall be set off within the equal amount.

B. Determination 1) In the contract, where there is a defect in the completed object or the completed part before the completion of the contract, the contractor may claim the contractor for the repair of the defect in lieu of the repair of the defect or together with the repair of the defect. The contractor's claim for the compensation of the defect is in a relationship of simultaneous performance with the contractor's claim for the compensation of the defect unless there are special circumstances. Thus, if the contractor holds the right to the compensation of the defect and exercises it, the contractor's obligation for the payment of the construction cost is not immediately omitted, and the contractor's obligation for the payment of the compensation of the defect is not attributable to the delay, and the contractor's obligation for the compensation of the defect or the compensation of the damage as the automatic claim for the payment of the remainder of the construction work as the set-off claim(see Supreme Court Decision 8DaDa18788, Dec. 12, 1989, etc.).

The fact that the document prepared on October 8, 2020, stating the defendant's expression of offset will, was served on the plaintiff on October 13, 2020, is significant in this court.

The Plaintiff’s claim for construction price expires within the scope of KRW 26,929,728 according to the Defendant’s expression of offset intention, and KRW 6,943,028 ( = 33,872).