1. The plaintiff's claim is dismissed.

2. The costs of lawsuit shall be borne by the Plaintiff.

1. Basic facts

A. The Defendant is a company that received a contract for a “C-style construction work” on the ground and five lots of land, both D and D, as ordered by the Defendant Company C (hereinafter “C”), and the Plaintiff is a company that received a subcontract from the Defendant for a reinforced concrete construction work (hereinafter “instant construction work”).

B. On September 30, 2016, the Defendant carried out the site descriptions on the instant construction project, and the site descriptions issued at the time were stated as “the construction period: 10 months prior to the commencement of the construction project, November 1, 2016.”

C. On January 11, 2017, the Plaintiff entered into a standard subcontract for the instant construction project (hereinafter “instant construction contract”) with the Defendant from January 11, 2017 to September 10, 2017, which stipulates that the construction period shall be KRW 5,00,000,000 (excluding value-added tax; hereinafter the same shall apply) with respect to the instant construction project, and thereafter a modified contract was entered into for four occasions as follows (hereinafter “each of the instant changes”).

The contract period (cost) of the first installment of the contract date of January 11, 2017 through January 31, 2017, 2017; the second revision from January 31, 2018 to January 31, 2018; or the second revision from January 11, 2017 to May 31, 2018; the third revision from January 18, 2017 to May 31, 2018; the 620,000,000 until May 11, 2018 to August 31, 2018; the 6,620,000,000,000,0000 or 00 on August 30, 2018; the 16, 2017; the 106,000,000,0000; and

D. On October 31, 2018, the Plaintiff completed the instant construction work, and on December 21, 2018, filed a claim for completion completion along with the completion fraternity and the completion inspection institute.

E. From March 2017 to January 2020, the Defendant paid all KRW 7,392,00,000,000, plus value-added tax of KRW 672,00,000, to the Plaintiff.

[Ground of recognition] Facts without dispute, Gap evidence Nos. 1 through 7 (including branch numbers; hereinafter the same shall apply), Eul evidence Nos. 4 and 5, the purport of the whole pleadings

2. Determination on the cause of the claim

A. The construction of the Plaintiff’s assertion 1 was delayed due to the Defendant’s fault, such as the delay in confirmation of the Defendant’s design drawing, the increase in construction volume following the design change, and the delay in the preceding process.