A. On March 4, 2011, the Plaintiff concluded a contract for construction works with the Defendant to “the construction work cost of KRW 3.52 million (including value-added tax) and the date of commencement, April 1, 2011, and November 30, 201, with the date of completion of the completion of the construction works, which decided on November 30, 201 and decided on the ground (including value-added tax), to “the construction work for the extension of education and research facilities in the Gosung-gun, Gosung-gun and Gosung-gun” on the ground (excluding 462-3

(hereinafter referred to as the “instant building,” and the said extended construction is called the “instant construction,” and the said contract is called the “instant construction,” and the said contract is called the “instant contract.”

The Plaintiff started the instant construction before the commencement date, and agreed on November 25, 201 to change the completion date of the instant construction project to December 31, 201.

C. On January 5, 2012, the Plaintiff requested the Defendant to provide that “The construction cost shall be increased by KRW 1,02,410,000 (including value-added tax) as a result of an additional construction work due to a design change, total floor area increase, etc.” (including value-added tax).

Accordingly, the defendant, who arranged to introduce the contract of this case, requested a review of the validity of the above amount requested to be increased to SamhoD Co., Ltd. (hereinafter referred to as the " SamhoD"), and after reviewing the validity of the above amount requested to be increased, SamhoD presented its opinion to the effect that "The above amount requested to be increased to KRW 462 million, which shall be reduced to KRW 462 million, and KRW 562.1 million, which shall be recognized."

In accordance with the above opinions of SamhoD, the Plaintiff and the Defendant concluded a modified contract (hereinafter “instant modified contract”) on March 15, 2012 with the content that the scheduled completion date will be delayed as of March 15, 2012, by increasing the construction cost of KRW 562,100,000 (including value-added tax) to KRW 4,088,210,000 (including value-added tax).

However, the contract under the instant modified contract was prepared on December 28, 201, retroactively from the date of the contract.

D. After completion of the instant construction, approval for provisional use on March 27, 2012, and approval for provisional use on the instant building on June 19, 2012.