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

The defendant shall pay to the plaintiff KRW 31,621,056 and KRW 18,861,056 among them.

1. Determination as to the cause of claim

A. On June 12, 2014, the Plaintiff, who is engaged in the shower selling business in the name of “D,” was awarded a contract for the Changcheon-si’s ground neighborhood living facilities and the new construction of detached houses for KRW 136,400,00 for construction cost, and the relevant additional construction cost (hereinafter “the instant additional construction”) was awarded to KRW 12,760,000 for construction cost. The fact that each construction was completed and delivered before the filing of the instant lawsuit does not conflict between the parties, or that it was recognized by comprehensively taking account of the respective descriptions in subparagraphs 1, 2, and 5 and the overall purport of arguments in the evidence No. 5.

B. Therefore, barring any special circumstance, the Defendant is obligated to pay to the Plaintiff the remainder of KRW 21,400,000, excluding KRW 115,000,000 for the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of the title of

2. Judgment on the defendant's defense

A. The defendant set-off 1) The defendant asserts that the part of the plaintiff's construction is defective and that 2,538,944 won needs to be maintained as offset against the plaintiff's claim for construction payment in lieu of defect repair. 2) The period for payment of the contractor's claim for construction payment is the time of completion or delivery of the object pursuant to Article 665 of the Civil Act, and the period for payment of the contractor's claim for defect repair or the damage claim in lieu thereof is the time when the contractor exercises his/her right.

In addition, the defect repair claim of the contractor or damage claim substituted therefor is concurrently performed with the contractor's contract price claim unless there are special circumstances. Therefore, the contractor who has ordered work holds the defect repair claim or the damage claim substituted therefor and exercises it.