1. Of the judgment of the first instance court, KRW 23,379,307 against the Plaintiff and its related thereto from May 22, 2014 to September 17, 2015 against the Defendant.

1. The reasoning for the court’s explanation on this part is as stated in Paragraph 1 of Article 420 of the Civil Procedure Act, except for the deletion of the part of “the construction cost required for additional works such as the above shall be the total of KRW 3,027,50,00,” which is set forth in Section 4 and 5 of Article 3 of the judgment of the court of first instance.

2. Determination as to the cause of claim

A. According to the facts of recognition as to the claim for the payment of the construction cost under the instant contract, the Plaintiff completed the private house construction under the instant contract, and the Plaintiff was paid a total of KRW 18,000,000 (= KRW 10,000,000,000) by the Defendant, and barring any special circumstance, the Defendant is obligated to pay the Plaintiff a total of KRW 31,50,000 for the construction cost of the private house unpaid to the Plaintiff (= KRW 49,50,000 (= KRW 45,00,000) - KRW 18,000,000) and damages for delay.

B. 1) Determination on the claim for additional construction costs requires a separate agreement between the contractor and the contractor on the execution of the additional construction and the payment of additional construction costs in order to recognize the contractor’s claim for additional construction costs. Determination on whether additional construction costs liability arises in determining whether additional construction costs incurred merely due to additional construction costs or changes in construction methods or designs, the contractor’s purpose of contract for construction works, the circumstances leading up to the contractor’s additional construction works, the details of the contract agreement and the contents of the additional construction works (whether exceeding ordinary scope), the ratio of the additional construction costs to the total construction cost. 2) First of all, the Plaintiff should determine whether the additional construction is made by taking into account all the circumstances, such as the purification tank, the front windows of the room, and cement outer walls, as the replacement and replacement costs for cement transactions.