1.The judgment of the first instance shall be modified as follows:

The Defendant-Counterclaim Plaintiff (Counterclaim Defendant) KRW 51,107,112.

A. In addition, the form of the above contract states that “the contract amount shall be applied by 80% of the labor cost portion among the contract amount between the Plaintiff and KS Construction, and, in the absence of any other special circumstances, the same application shall apply.”

In the above contract form, it is difficult to view the above contract form as a regular contract because there is no signature and seal between the plaintiff and the defendant, and it is difficult to view the subcontract price for the temporary installation and contact installation work in the above contract form as 80% of the labor cost.

② The Plaintiff’s employees H and the Defendant’s employees E sent e-mail on April 11, 2014 indicated as “the current status of progress of construction” files (Evidence B) attached to the Plaintiff’s e-mail, as follows: F Temporary Permanent Electrical Construction (Contract Amounting to KRW 788,770,00, KRW 340,000, KRW 340,000)” in relation to the subcontract rate and the amount of the lower-level subcontracting contract, “Chro Temporary 1” in relation to the subcontract price and the lower-level subcontracting contract amount, *80%) *80%”, “e-mail 2” in the instant case.

③ In relation to the settlement of construction cost between the Plaintiff and the Defendant, opinions have been exchanged on a working-level basis.

In the form of evidence No. 6, “The contract amount” was determined as “80% of the labor cost portion out of the contract amount between the Plaintiff and the Defendant,” and the Plaintiff’s employees H and the Defendant’s employees E exchanged their opinions “Y 1 temporary entertainment work (labor cost*80%)*80%,” “Y 2 temporary entertainment work (labor cost*80%), and “Labor cost*80%)” *80%, in consideration of the fact that the Plaintiff and the Defendant exchanged their opinions, it is the method of settling the subcontract price for the temporary and earthing work in this case, and it is determined that 80% of the labor cost was first applied to both the temporary and earthing work in order to reflect the original opinion and to reflect the changed circumstances thereafter.