1. The part concerning the principal lawsuit and counterclaim in the judgment of the court of first instance shall be modified as follows:

The Defendant-Counterclaim Plaintiff (Counterclaim).

A principal lawsuit and a counterclaim shall be deemed simultaneously.

1. Basic facts

A. The Plaintiff is a company that runs the business of installing gas facilities, and the Defendant is a company that runs the construction business and piping heating business.

B. On April 1, 2013, the Defendant concluded a facility project contract (including gas construction) with Kim Marine Development Co., Ltd. (hereinafter “Seoul Marine Development”) on the floor-based multi-purpose apartment construction project, Kim Young-young, and subcontracted to the Plaintiff on April 26, 2013, gas construction (hereinafter “the first construction project”) during the foregoing construction project, and on April 23, 2014, gas supply pipes outside the apartment site (hereinafter “the second construction project”).

C. On November 20, 2014, the Plaintiff and the Defendant concluded a gas construction contract for the establishment and use of Seongdong-do apartment (25,850,000 won for the construction cost) and the gas construction contract for the Gicheon-si Station (29,700,000 won for the construction cost) on November 20, 2014, and the Plaintiff completed all of the construction works within the respective construction contract period. From September 6, 2013 to May 19, 2015, the Defendant paid the Plaintiff KRW 235,290,000 as the total construction cost for each construction project, including the above paragraph (b).

At the time of entering into the instant construction contract, the Plaintiff and the Defendant agreed to lay gas pipes as shown in the Appendix 1 (hereinafter “the first drawing”). However, the Plaintiff laid underground gas pipes as shown in the Appendix 2 (hereinafter “amended drawing”).

[Ground of recognition] Facts without dispute, Gap evidence Nos. 1, 2, 3, Eul evidence Nos. 1, 2, 3, 6, 9 (including each number), and the purport of the whole pleadings

2. Determination

A. The fact that the Defendant paid the Plaintiff the construction cost of KRW 2,00,000 to the Plaintiff does not conflict with each other, barring any special circumstance, the Defendant seeks to pay the Plaintiff the said construction cost of KRW 2,00,000 as well as the said construction cost of KRW 2,00 after the Plaintiff completed all the construction works.