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

The defendant shall pay to the plaintiff KRW 45,175,142 on December 2016.

1. Facts of recognition;

A. On August 2015, the Plaintiff was awarded a contract with the Defendant for remodeling D-dong (hereinafter “instant building”) of the building D-dong (hereinafter “instant construction”).

B. From the beginning of August 2015 to the end of September 2015, the Plaintiff completed the instant construction work by bringing the construction cost of KRW 322,255,142.

[Ground of recognition] Facts without dispute, Gap evidence 1, 2, 6, 7 evidence, Eul evidence 1 (including each number), appraiser C's appraisal result and inquiry result, the purport of the whole pleadings

2. Judgment on the ground of the Plaintiff’s claim

A. According to the fact that the Defendant’s obligation to pay the construction cost was acknowledged, the Defendant is obligated to pay the Plaintiff the construction cost of this case in KRW 322,255,142, and delay damages, barring any special circumstance.

B. As to the instant construction amount, the Plaintiff alleged that the instant construction amount was KRW 379,940,000. However, the Plaintiff stated that the contract amount was not prepared at the time of the conclusion of the instant construction contract, and that the Defendant did not conclude a contract by confirming the construction amount. In light of the characteristics of the remodelling project, the Defendant’s above statement that the construction amount was not determined from the beginning is sufficiently paid, according to the first instance appraisal document, the instant construction amount was appraised as KRW 322,25,142, and the amount of the written estimate submitted by the Plaintiff was appraised as KRW 322,25,142.

In light of the order and progress of the instant construction project, including there is no evidence to deem that the amount was actually invested in the instant construction project, the evidence, such as evidence Nos. 3 and 5, presented by the Plaintiff is insufficient to recognize the Plaintiff’s above assertion as to the construction amount.

Therefore, since the construction amount of this case is reasonable to be determined in KRW 322,255,142 as the result of appraisal at the court below, the plaintiff's assertion is rejected.

3. Judgment on the defendant's assertion or defense

A. The Defendant’s assertion to revoke the construction contract party’s mistake.