1. The Defendant (Counterclaim Plaintiff) paid KRW 16,134,500 to the Plaintiff (Counterclaim Defendant) and its related amount from March 1, 2014 to January 19, 2016.

1. Basic facts

A. The Plaintiff is a person who runs the construction business, design, waterproof, and painting business under the trade name of “C,” and the Defendant is a building owner of the Daegu Suwon-gu Diallet (hereinafter “instant loan”). The Plaintiff is the owner of the new construction and the owner of the foregoing loan.

B. On January 2014, the Plaintiff and the Defendant entered into a standard subcontract agreement for construction works (hereinafter “instant construction contract”) with respect to the construction work for the stoning of outer walls and the private room construction work from April 20, 2013 to February 20, 2014; the construction work price of KRW 19 million per square meter; the construction work price of KRW 20,000 per square meter; and 3/1000 per square meter; and the main contents of the contract are as follows.

(1) A subcontractor shall perform construction works under the terms and conditions of this contract and design documents (including drawings, specifications, construction specifications, site descriptions, etc.; hereinafter the same shall apply).

Article 15 (Change or Increase of Construction Work) (1) A (Defendant) may, if deemed necessary, request in writing the modification of the details of construction work or the temporary suspension of construction work.

As a result, if it is necessary to extend or reduce the contract period or to increase or decrease the contract amount, it is decided in consultation with B.

(2) An increase or decrease in the contract price under paragraph (1) shall be in accordance with the following standards:

The unit price of the volume of construction increased or decreased by the association to be established shall be the unit price on the calculation sheet under Article 2 (2) (hereinafter referred to as the "contract unit price").

Special number of cases: Provided, That if the quantity exceeds the quantity, it shall be calculated by mutual agreement.

C. On the other hand, around December 26, 2013, which was prior to the conclusion of the instant construction contract, the Plaintiff written and delivered a written statement to the Defendant related to the instant construction project, stating “32,00 won per 32,00 square meters per m2,000 square meters per m2,000 square meters, 610 square meters per m20,520,000 won per m20,000 per m20,000 per m20,000 per m20,000 per m2,000 won.”

According to the design drawings before the change of the loan of this case, the front copon part of the Dong side 1.