1. All appeals filed by the Defendant (Counterclaim Plaintiff) and the counterclaim claims added in the trial are dismissed.

2. After an appeal is filed.

1. The reasoning of the judgment of the court of first instance as to the claim for return of unjust enrichment with respect to the Defendant’s additional payment of the construction price, as stated in the second sentence from the third to the fourth above of the judgment of the court of first instance, shall be as follows. In addition, the Defendant added “2. Additional Determination” as to the selective counterclaim added in the court of first instance as stated in the reasoning of the judgment of the court of first instance, and thus, it shall be cited in accordance with the main sentence of Article 420 of the Civil Procedure Act.

In light of the following circumstances that can be seen by comprehensively taking account of the records in Gap's evidence Nos. 7, 9, and 10 evidence, the fact-finding response results to the head of the apartment management office of this court, and the purport of the entire pleadings, the evidence submitted by the defendant alone is insufficient to acknowledge that the defendant paid additional construction cost as to the "the construction contract of this case" and that the plaintiff A obtained the same amount without any legal cause, and there is no other evidence to acknowledge this portion of the claim. Therefore, the defendant's claim is without merit. (i) The contract term of the construction contract of this case was from November 2, 2009 to September 30, 201, and the completion and occupancy of the apartment building of this case was made around November 201. The defendant asserted that the defendant paid additional construction cost, etc. for the construction contract of this case to the defendant, including the plaintiff A's "the construction work of this case," and that the construction cost of this case was not included in the "the construction work of this case."

Article 20 (1) of the Civil Code shall apply to the defendant.