1. The Defendant (Counterclaim Plaintiff) paid KRW 56,673,600 to the Plaintiff (Counterclaim Defendant) and its amount from August 14, 2013 to October 8, 2015.

The principal lawsuit and counterclaim shall also be deemed to have been filed.

1. Basic facts

A. Around August 201, C entered into a contract with the Defendant with the content that the construction work of constructing two sirens (six households; hereinafter “each of the instant buildings”) on Pyeongtaek-si D and E on the ground (hereinafter “instant building”) was to be entered into within five months after the commencement of the construction (hereinafter “instant new construction work”).

B. On November 15, 201, the Plaintiff entered into a subcontract with C by stipulating that the instant new construction work was “a separate agreement for additional construction costs, such as a price of KRW 368,00,000/1, internal interior interior interior interior interior and external interior and external construction.” On the same day, C and the Defendant agreed to receive 368,000,000,000 and additional construction costs directly from the Defendant.

C. Around June 2012, the Plaintiff completed the instant new construction project, and received KRW 799,000,000 in total from the Defendant as the price for the instant new construction project.

On the other hand, the amount of damages, such as reconstruction costs, etc., is a total of 14,771,00 won as shown in the attached Table, because there are defects such as water leakages and sinkings in the new construction of this case.

[Ground of Recognition] Facts without dispute between the parties, entry of Gap evidence Nos. 1 through 5 and 10 (including each number; hereinafter the same shall apply), the result of the verification and entrustment of appraisal by this court, the purport of the whole pleadings

2. Summary of the parties' arguments

A. The gist of the Plaintiff’s assertion is KRW 736,00,000 (i.e., KRW 368,000,000). Additional construction works, such as windows, electricity, and Apt (hereinafter “Additional construction works, such as the title, etc.”) in each of the instant buildings are KRW 84,00,000 (= KRW 42,000,000). Since then, additional construction works are carried out for the completion of each of the instant buildings (hereinafter “Additional construction works, such as the title, etc.”) and the price is KRW 84,00,000. The additional construction works are carried out for the completion of each of the instant buildings (hereinafter “Additional construction works”). The construction cost of KRW 4,898,00,00; KRW 2,980,000; the construction cost of gas pipes installed outside telecommunications; KRW 3,000,000; and ancillary civil construction works.