A. In 2014, the Plaintiff was awarded a contract for a new construction work of a detached house located in Dok-si.

The plaintiff, among the construction works of the above single-family housing, subcontracted construction works of piping facilities (hereinafter referred to as "the pipeline construction works of this case") to the defendant with the construction cost of KRW 6 million.

B. From among the instant pipeline construction works implemented by the Defendant, the number of water leakages occurred in a detached house on May 28, 2015 after the completion of the construction of a detached house due to poor connection of water supply pipes.

C. The Plaintiff, on behalf of the Defendant, executed a defect repair work for the number of single houses.

The Plaintiff remitted to the Defendant the sum of KRW 4.9 million on September 5, 2014, KRW 3 million, KRW 400,000 on October 6, 2014, KRW 100,000 on October 29, 2014, and KRW 5,00,000 on November 12, 2014, KRW 1.1 million on a check.

E. Meanwhile, the Plaintiff, other than the instant pipeline construction, contracted for a new construction of a detached house located in the FF from E, and subcontracted the construction of piping facilities among the said new construction works to the Defendant with the construction cost of eight million won. However, E did not pay part of the construction price to the Plaintiff on the ground that the said new construction of a detached house was not performed and defective.

The Plaintiff paid 6,300,000 won to the Defendant as the construction cost according to the pipe construction work height among the above new construction works for detached houses.

[Ground of recognition] Facts without dispute, Gap's entries in Gap's evidence 1, 3 through 5, 7 through 9, 15 through 18 (including branch numbers unless otherwise indicated) and the purport of the whole pleadings

2. Determination

A. According to the above facts, since the defect in the pipe construction of this case executed by the defendant caused the leakage of the detached house, the defendant is obligated to pay to the plaintiff the sum of the expenses paid by the plaintiff as the repair work for the defects in the detached house and the delay damages therefor as follows.

- The wood construction cost: 8,812,400 won No. 11-4, A.