A. On July 9, 2018, the Plaintiff entered into a contract for the supply and installation of solar energy storage devices (hereinafter “instant construction contract”) with the Defendant and the Defendant from July 9, 2018 to August 30, 2018 (based on pre-use inspection) with respect to the supply and installation of the 443kwh energy storage devices (ES; hereinafter “instant devices”) (hereinafter “instant construction works”) among the E projects to be performed on the ground D in Ansan-si (hereinafter “C”), under a subcontract with the Defendant Co., Ltd. (hereinafter “C”) on March 12, 2018.

B. The place where the instant device was installed was modified in the form of extension from the original land to the second floor of the building, and the Defendant additionally requested the Plaintiff to perform fire fighting and pentice construction.

C. On October 10, 2018, the Plaintiff concluded a fire-fighting service contract with F Co., Ltd. with a contract amount of KRW 1,650,000, and entered into a fire-fighting system installation contract with H operating G around January 2019 with a contract amount of KRW 7,700,000, respectively.

Upon entering into each of the above contracts, the Plaintiff paid each of the above payments, and paid KRW 1,257,000 to I who performed works to install fences on October 23, 2018.

The Plaintiff completed the instant construction work and received a pre-use inspection on November 23, 2018.

E. From July 27, 2018 to April 17, 2019, the Defendant paid to the Plaintiff KRW 187,00,000 as the instant construction cost.

【Fact-finding without any dispute over the ground for recognition】 1-1, 2-2, 2-1, 3-2, 3-1, 2-2, and 6-1, 3-2, and 6-2, the purport of the whole pleadings

2. Judgment on the parties’ assertion

A. The summary of the parties’ assertion (1) The Plaintiff is against the Defendant the remainder of the construction cost under the instant construction contract (hereinafter “the remainder of the construction cost”) KRW 55,000,000 (i.e., KRW 242,00,000 - KRW 187,000,000). The instant lawsuit is filed from December 2, 2018, following the due date for the payment of the remainder of the construction cost.