A. On October 1, 2016, the Plaintiff (contractor) and the Defendant (contractor) concluded a construction contract with the content as indicated below (hereinafter “instant construction contract”).

0. Name of construction: The construction site for machinery and equipment and the construction site for fire fighting works among the newly constructed construction works of Category C multi-family housing: The construction period for eight parcels, other than Ulsan-gun, Ulsan-gun, and the 0 lots of land: the beginning date of July 1, 2016; the contract price on July 30, 2017: 609,000,000 won, and value-added tax exemption.

B. The Plaintiff completed construction under the instant construction contract, and the Defendant paid the Plaintiff KRW 579,920,000 in total as construction cost.

[Grounds for recognition] Unsatisfy, Gap evidence 2, and the purport of the whole pleadings.

2. The parties' assertion

A. The Plaintiff asserted that the construction work under the instant construction contract was completed.

After the instant construction contract, the Plaintiff, under agreement with the Defendant, performed additional construction work equivalent to KRW 9,401,177 in the part of the Fire Fighting System and KRW 45,620,089 in the part of the Mechanical Equipment Construction Work, and promised to preserve the value-added tax of KRW 536,170, and KRW 44,297,862 in the amount of the Mechanical Equipment Construction Work to be reduced directly by the owner of the building. Accordingly, the Plaintiff agreed to reduce the amount to be additionally paid out of the construction cost of the instant case by the owner of the building.

The Defendant paid only KRW 579,920,00 among the construction cost of the instant case ( KRW 609,00,000, KRW 9,401, KRW 1777, KRW 45,620,089, KRW 536,170, KRW 44,297,862), and did not pay the remainder of the construction cost.

B. The defendant asserted that there was no agreement between the plaintiff and the defendant on the increase in the construction price of this case.

around August 2018, the Plaintiff and the Defendant agreed to pay KRW 29,080,000 among the construction cost of the instant case by reducing the construction cost.

Therefore, by paying KRW 579,920,00 to the Plaintiff, the Defendant paid all the construction cost of the instant construction contract.

3. Determination

A. The Plaintiff’s judgment on the Plaintiff’s additional construction cost is based on KRW 11,259,574,000,000 among the Defendant.