1. The plaintiff (Counterclaim defendant)'s appeal against the principal lawsuit is dismissed.

2. The Defendant-Counterclaim Intervenor (Counterclaim Plaintiff) is dissatisfied with this.

1. Basic facts

A. The Plaintiff (the Plaintiff’s trade name was a “stock company grass construction,” and the trade name was changed as of January 17, 2017) was awarded a contract for an engineering work as a company for the purpose of an engineering work, etc., and a construction work of constructing a “D” building on the second underground floor and the seventh floor of the ground level from A, who had operated a mutual intent company called “J” around April 20, 2015, for the purpose of the construction work (hereinafter “new construction work of this case”) at the contract price of KRW 11.86,350,00 (including value-added tax, hereinafter the same shall apply).

(A) evidence of heading 1.b.

After that, among the new construction works in the instant case, the Plaintiff’s subcontract period for civil engineering works, such as ground-breaking and soil mounds, file-routing works, and installation and dismantling works of provisional facilities (hereinafter collectively referred to as “subcontracts in this case”) to the Defendant. From April 28, 2015 to May 4, 2015, the contract price of KRW 1.49 billion for the subcontracted works in this case with the Defendant is KRW 1.3.8 million, and the period of construction from May 28, 2015.

7. A subcontract (Evidence A2) was concluded as of July 23, 2015, with a view to the construction of soil-related parts on July 23, 2015 based on the HHET PLE method instead of the method of construction on the earth stream board, and concluded a subcontract modification contract (Evidence B8) with a contract amount of KRW 1.65 billion (hereinafter “the subcontract price in this case”) to increase the contract amount to KRW 1.65 billion and to extend the termination date of the construction period to August 30, 2015.

C. Accordingly, around November 11, 2015, the Defendant completed all remainder of the subcontracted construction of this case, excluding the demolition of provisional facilities, and completed the demolition of provisional facilities by February 23, 2016.

Meanwhile, from December 2015 to January 2016, the Defendant transferred the part of KRW 558,177,475 (Evidence 1, 2, and 32) out of the instant subcontract consideration claims against the Plaintiff to a transaction entity, such as “F,” which is operated by E, from around December 2015 to around January 2016 (Evidence 1, 2, and 31). On October 12, 2017, the Intervenor seized and assigned the part of KRW 165,289,196 out of the Defendant’s claim against the Plaintiff.