A. The Defendant is engaged in a building business with the trade name called C, and the Plaintiff is a person who operates building equipment business with the trade name called D, and the Plaintiff and the Defendant concluded a subcontract with the Plaintiff, from around 2010, to have the construction work performed by the Defendant subcontracted the part of the construction work performed by the Defendant to the Plaintiff.

B. According to the above subcontract, the Plaintiff completed construction on October 2012, 2012 by performing each external stone construction of the studio construction works located in Asan City E, F’s studio construction works, G’s studio construction works, and the studio construction works located in Seo-gu, Seo-gu, Seo-gu, Seo-gu, Incheon.

C. As a result of this court’s entrustment to appraiser I with respect to each of the above outside works executed by the Plaintiff, the construction cost is KRW 214,859,500.

(A) According to the above appraisal commission, in addition to the above amount, the above amount is stated as "181,907,182 won when the unit price of the defendant's assertion is applied." This is based on the defendant's assertion premiseding that there was an agreement between the plaintiff and the defendant to discount the unit price of building stones by item. However, there is no evidence to acknowledge the existence of the above agreement.

The Plaintiff received KRW 159,900,000 from the Defendant for each of the above construction costs.

[Ground of recognition] Unsatisfy, entry of Gap evidence 1 to 5, the result of a request to appraiser I by this court for appraisal, the purport of the whole pleadings

2. According to the above facts of recognition, the defendant is obligated to pay to the plaintiff 54,959,500 won (=214,859,500 won - 159,900,000 won) and damages for delay at the rate of 20% per annum from November 1, 2012 to December 11, 2014, which is the date of the instant judgment, as sought by the plaintiff, after the completion date of construction in this case.

With respect to the price of each of the above external works, the defendant shall have the aggregate of KRW 50,00,000, KRW 50,000,000, KRW 18,915,00, KRW 22,465,10 in order, among the plaintiff, 151,381.