1. The first instance judgment, including a counterclaim claim added by this court, is modified as follows.

A principal lawsuit and a counterclaim shall be deemed simultaneously.

1. Basic facts

A. The Plaintiff and the Defendant’s status are companies whose purpose is building assembly construction business, etc. and which re-subcontract part of the construction work supplied by C (hereinafter “C”) to the Defendant as follows, and the Defendant is a contractor as a company that manufactures construction materials.

B. The Plaintiff entered into the first construction contract between the Plaintiff and C) around October 2014, the Plaintiff Company C (hereinafter “C”).

B) As between the Plaintiff and C, the part of the non-refited steel works among D construction works and the part of the production and installation works of the external panel (hereinafter referred to as “instant subcontracted works”).

1,675,000,000 of the construction cost (excluding value-added tax)

A contract for construction works (hereinafter the same shall apply) and the period of construction shall be determined from September 17, 2014 to March 31, 2015, and each contract for construction works (hereinafter referred to as "contract for first construction works") shall be concluded.

(2) According to the construction specifications (Evidence No. 24) prepared at the time of the conclusion of the first construction contract, the construction amount was calculated by adding the total amount of KRW 33,282,760, including all kinds of insurance premiums, industrial safety management expenses, retirement mutual-aid installments, payment guarantee fees, etc., to the total amount of KRW 1,641,717,240 for total construction costs, labor costs, and expenses.

C. On October 2014, the Plaintiff and the Defendant entered into a contract for the second construction works between the Plaintiff and the Defendant. The part of the Plaintiff’s construction works, the sum of material cost, labor cost, and expenses, among the subcontracted construction works in the instant case, falls under KRW 771,86,840, except for the portion of “ISOWAL SYST YES production and installation work” (hereinafter “instant construction work”).

(1) A contract under which the contract is to receive a re-subcontract with the amount of construction cost of KRW 583,00,000 and the period of construction period of construction from September 17, 2014 to March 31, 2015 (hereinafter “second construction contract”).

A) The construction specifications made at the time of the conclusion of the second construction contract (as a result of the evidence A No. 1, the construction amount is total.