공사대금
1. The plaintiff's appeal is dismissed.
2. The costs of appeal shall be borne by the Plaintiff.
Purport of claim and appeal
1...
1. The reasons for this part of this Court’s reasoning are as follows: “Defendant (Co., Ltd. B before the change)” in Part 9 of the second sentence of the judgment of the court of first instance shall be deemed as “Defendant (Co., Ltd. B before the change) on May 27, 2014,” and the reasons for the judgment of the court of first instance are as stated in Article 420 of the Civil Procedure Act, and this shall be cited by the main sentence of Article 420 of the Civil Procedure Act.
2. Judgment as to the plaintiff's primary claim
A. The gist of the Plaintiff’s assertion was that the Plaintiff calculated the Plaintiff’s construction area as total floor area of 3,584 square meters ( approximately 11,851 square meters), excluding the balcony part of the instant apartment building, and entered into the instant contract on the condition that the Plaintiff would receive construction cost of KRW 600,000 per square meter from the Defendant, at the time of entering into the instant contract for construction works with the Defendant (hereinafter “instant contract”).
However, in the part where the Plaintiff actually performed the structural construction of the instant apartment, the area of the said balcony was included in the area of 807.948 square meters in excess of the said total floor area (hereinafter “instant balcony”).
Although the Plaintiff’s duty to undertake the instant construction work is limited to the above total floor area, as long as the Plaintiff completed the instant balcony construction work by mistake, the Defendant is obligated to pay the Plaintiff for unjust enrichment, such as KRW 484,768,80 (i.e., the above 807.948 square x 600,000) equivalent to the expenses for the structural construction of the instant balcony constructed in excess.
B. Article 741 of the Civil Act provides that “A person who gains a benefit from another person’s property or service without any legal cause and thereby causes a loss to another person shall return such benefit.”
In the case of the so-called unjust enrichment for which one of the parties has paid a certain amount of benefits according to his own will and then claims the return of benefits on the grounds that there is no legal ground.