1. The Defendant’s KRW 716,139,90 to the Plaintiffs and 6% per annum from August 29, 2017 to November 11, 2020, respectively.

1. Basic facts

A. 1) The Plaintiffs constitute a joint supply and demand organization on November 24, 2004, and the Public Procurement Service and the demanding administrative agency on November 24, 2004 as Defendant “F Construction Works” (hereinafter “instant Construction Work”).

As to the total cost of the contract, the contract amount of KRW 2,206,00,000 shall be additionally stated as the total contract amount of KRW 2,200,000,000 and the contract period of KRW 2,206,00,00 and the contract period of KRW 31, 204 from November 25, 2004 to December 31, 2004 (hereinafter “instant contract for a long-term contract”) and the contract for a single-term contract for a long-term contract (hereinafter “instant contract for a long-term contract”). If it is necessary to distinguish between the general contract and the contract for a single-term contract, the instant overall contract for a contract for a general contract and the

2) Of the general conditions of the construction contract applicable to the instant construction contract (hereinafter “instant general conditions”), the part relating to the instant case is as follows.

Article 20 (Adjustment of Contract Amount Due to Modification of Design) (1) If there occurs an increase or decrease in the volume of construction works, such as a change of construction methods for modification of design, or a change of input materials, the contracting officer shall adjust the contract amount according to the following standards:

1. The unit price for the increased or decreased volume of construction works shall be the agreed unit price;

However, if the contractual unit price is more than the budget unit price and the quantity is increased, the applicable unit price for the increased quantity shall be the budget unit price.

2. The unit price for an item or a item without a detailed statement of calculation (including where the performance, standard, etc. are different even for the same item; hereinafter referred to as "new item") shall be calculated by multiplying the unit price calculated on the basis of the rate of successful tender (referring to the rate of the successful tender price or the contract price for the same item; hereinafter the same shall apply) at the time of design modification (where the design drawing needs modification, referring to the time the agency awarding the contract determines the modified drawings, and where the modification of the design drawing is not required, referring to

(4) Paragraph (1).