1. The judgment of the first instance, including the claim of the Plaintiff’s succeeding intervenor added at the trial court, shall be modified as follows.

In the first instance court, the Plaintiff filed a claim against the Defendants for the remainder of the construction cost of KRW 31,253,500 and damages for delay. The first instance court accepted the above claim of KRW 31,00,000 and dismissed the remainder of the claim.

As to this, only the Defendants appealed against the part against which they lost, the subject of this Court’s adjudication is limited to the claim of KRW 31,00,000, which was cited as above.

Basic Facts

On January 18, 2016, Defendant C entered into a contract for a construction project with the Plaintiff based on the contract price of 65,000,000 won (the down payment of 5,000,000 won on February 25, 2016, the intermediate payment of 5,000,000 won on March 7, 2016, the intermediate payment of 10,000 won on March 14, 2016, the remainder of 15 days after completion, the remainder of 45,00,000 won on March 14, 2016, the date of commencement, and the date of completion).

Defendant D signed and sealed the above contract as the guarantor of Defendant C who is the contractor.

On June 1, 2016, the Plaintiff and the Defendants changed the construction cost of the said construction contract to KRW 67,500,000, and changed the payment date to “the remainder payment within 20 days after completion of the construction work, including KRW 10,000,000 for reconstruction, KRW 5,000,000 prior to external construction, and KRW 34,50,000 for the remainder.”

(hereinafter “instant construction contract.” The Defendants paid the Plaintiff KRW 5 million on February 25, 2016, KRW 10 million on March 23, 2016, KRW 3 million on April 11, 2016, and KRW 25,287,00 in total, KRW 25,287,000 on June 21, 2016.

The Plaintiff and the Defendants agreed on the payment of the construction cost, around June 2016 to July 7, 2016, concluded that the Plaintiff’s construction works in the instant construction contract, excluding the remainder, as it is, and the Defendants’ direct management of the portion, “the construction works in the instant construction contract.” The Plaintiff’s oral agreement to settle the construction cost as the construction cost actually invested in the said construction area.

(hereinafter “instant agreement”). The Plaintiff’s completion of construction is the instant agreement around July 2016.