1. The plaintiff's claim is dismissed.

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

1. The parties' assertion

A. The gist of the Plaintiff’s assertion: The Defendant contracted several construction works from C at the construction site, and subcontracted the part of the joint-use construction to D (mutual: E).

D In addition to the construction works subcontracted by the Defendant as above, even though the “additional Construction Works” equivalent to KRW 37,622,432 (including value-added tax) was not paid for the said Additional Construction Works, on July 30, 2014.

The Plaintiff was transferred from D the above additional construction cost claim against the Defendant.

Therefore, the defendant is obligated to pay the above additional construction cost to the plaintiff.

B. The gist of the defendant's assertion: since the defendant paid all the construction cost incurred in subcontract transactions to D, the defendant is not obligated to pay the unpaid debt.

D The part of the construction work performed by the Defendant around July 30, 2014 is limited to the repair of defects or deficiencies in the completed construction work, and it is not a new additional construction work. Thus, there is no additional construction cost obligation that the Defendant is obliged to pay to D.

2. The key issue of this case is whether D's additional construction cost claims against D exist or not.

In the instant case, the Defendant and D determined the total construction cost for approximately 16 joint construction works from May 2014 to July 2015, respectively, and concluded a subcontract construction contract and continued construction works. As long as the method of settling actual quantity is not a contract, there is an additional construction cost in addition to the details of construction works under the original contract, and as a matter of course, there is no additional construction cost. In order to recognize additional construction cost claim, in principle, there is a separate agreement between the contractor and the contractor on the implementation of additional construction and the payment of additional construction cost.

However, evidence No. 1, witness F and D's testimony, fact-finding results by Hongsung Tax Office and the whole purport of pleadings are recognized.