1. The Defendant’s KRW 53,224,60 and the Plaintiff’s 6% per annum from May 3, 2019 to January 28, 2021, and the following.

1. Basic facts

A. 1) The Defendant was planning to newly construct and sell a primary complex building on the ground of Seongdong-gu Seoul Metropolitan Government, Seongdong-gu.

2) Accordingly, on March 13, 2017, the Defendant contracted the Plaintiff the construction cost of KRW 8,559,000,000 for the construction of the composite building in Seongdong-gu Seoul Metropolitan Government (hereinafter “instant contract”). The main content of the instant contract is as follows.

- The total floor area of the construction: 5,358 square meters (1,621.04py): the contract amount: 5,59,000 million won (in the case of 8,59,000,000 for sale and subdivision, the basis for the final authorization drawings of the permitting authority) 5,280,000/ square meters (based on the final authorization drawings of the permitting authority) - Article 17 (Adjustment of the contract amount due to a modification of a design) (1) the project does not adjust the contract amount as a contract (total contract) with the unit price fixed by unit area.

However, the contract amount may be adjusted exceptionally only in the following cases:

(2) Where an increase or decrease in the total floor area of a construction project occurs as a result of a design change requested by "A (Defendant)", the construction amount shall be adjusted according to the increased total floor area of a construction project according to the unit area (construction amount / construction area expense) at the time of the conclusion of this contract

B. After the completion of the construction, the Plaintiff newly constructed a complex building (D) with the main floor size of 20 stories above the third ground level above the ground level around April 2019, following the commencement of the construction in accordance with the instant contract.

【Ground for Recognition: Facts without dispute, entries in Gap evidence Nos. 1, 2, and 4, and the purport of the whole pleadings

2. Article 22 (Principles of Contracts for Construction Works) (1) of the related Acts and subordinate statutes.

The parties to a contract (hereinafter the same shall apply) shall enter into a contract on an equal footing by agreement and fairly, and shall conscientiously perform the contract in good faith.

(3) The Minister of Construction and Transportation shall make a contract for construction works to ensure that the contracting parties enter into a contract fairly on equal terms.