1. The plaintiff's appeal, the main claim extended in the trial and the additional conjunctive claim are all dismissed.

2...

1. Basic facts

A. On July 31, 2014, the Defendant entered into a contract for the construction of a factory extension project (hereinafter “instant construction project”) with D, under which the construction cost of KRW 1,407,00,000 (excluding value-added tax) was KRW 1,407,00 (hereinafter “the primary construction project”); and the Plaintiff entered into a contract for business transfer and acquisition with the content that the rights and obligations under the said construction project are comprehensively transferred from D. B. Accordingly, the Plaintiff and the Defendant concluded a contract for the instant construction project (hereinafter “the secondary construction project”) and subsequently increased the construction cost of KRW 1,60,000 (excluding value-added tax).

On the other hand, the provisions concerning the adjustment of the contract amount among the general conditions of the standard contract for private construction works attached thereto are as follows.

[General Conditions of Standard Construction Contract for Private Construction Works] Article 19 [Adjustment of Contract Amount due to Modification of Design] (1) In a case where the contents of the design do not coincide with the condition of the construction site, or where there is any uncertainty, omission or error, or unexpected circumstances concerning the construction, or where the installation of facilities is required due to the modification of the project plan, etc., “A” must be modified.

(2) Where a change in the volume of construction works occurs due to the modification of a design under paragraph (1), the contract price shall be adjusted according to the following standards, and the construction period shall be extended or shortened, if necessary:

1. The unit price for the increased or decreased construction works shall be determined through mutual consultation on the basis of the unit price indicated in the calculation sheets under Article 8;

2. The unit price for a new item not included in the calculation sheet shall be the unit price calculated at the time of design modification;

3. The rate specified in the calculation sheet shall apply to general management expenses and profits, etc. for increased or decreased construction works;

Article 21 (Adjustment of Contract Amount Due to Amendment to Terms and Conditions of Contract) (1) Other than cases pursuant to Articles 19 and 20, the contract amount shall be adjusted due to the amendment to the terms and conditions of contract.