1. The part of the judgment of the court of first instance against the plaintiff, which orders payment below, shall be revoked.

The defendant.

1. Determination on the cause of the claim

A. According to the facts without dispute, Gap evidence Nos. 2, 4, 6, and 7, and the purport of the whole pleadings, according to the purport of the whole pleadings, the plaintiff newly built by the defendant, the 4th residential house located in Gangwon-do, Gangwon-do, Seoul (hereinafter "the building of this case"), the defendant obtained approval for the use of the above residential house on July 10, 2018, and completed registration of the preservation of ownership on the 12th day of

It is recognized that the Plaintiff received KRW 5,400,000,000 from the Defendant on February 13, 2018 for the construction cost of the pipelines for the installation of air conditioners, and the Plaintiff received KRW 2,00,000,000 from the Defendant on February 9, 2018, and the Plaintiff received from the Defendant on February 13, 2018.

Therefore, unless there are special circumstances, the defendant is obliged to pay the remainder of the construction cost of KRW 1400,000 and delay damages therefor to the plaintiff.

B. As to this, the defendant paid 600,000 won as repair cost because there is a defect in water leakage in the pipe constructed by the plaintiff, and since the plaintiff failed to close the outer wall after installing the pipe, it additionally paid 2,050,000 won as construction cost of the outer wall, the above expenses are deducted and the construction cost to be paid to the plaintiff is not remaining.

According to the whole purport of evidence No. 3-1 to No. 10, evidence No. 1-1 to No. 2-3, evidence No. 2-1 to No. 2-3, and evidence No. 470,000 won additionally paid to D, who is an air-conditioner installer, in order to repair leakage of the pipelines installed by the Defendant during the process of installing air-conditioner in the instant building around May 2018, it is recognized that the Defendant discovered the water leakage of the pipelines installed by the Defendant, although the Defendant demanded the Plaintiff to repair the defects, the Plaintiff did not demand the Plaintiff to pay additional KRW 470,000,000, while the Defendant demanded to pay additional KRW 470,000 to repair the leakage defects of the pipelines.

Therefore, the defendant's defense that the 600,000 won of the repair cost of the piping installed by the plaintiff should be deducted from the payment of the construction cost is justified.

B. On the other hand,