1. All of the plaintiffs' claims are dismissed.

2. The costs of lawsuit are assessed against the plaintiffs.

1. Basic facts

A. On May 13, 1991, the Defendant completed the registration of ownership transfer with respect to the Seongdong-gu Seoul Metropolitan Government D large-264 square meters (hereinafter “instant land”).

On the ground of the instant land, there is a house of 375.24m2 (hereinafter “instant building”) with the roof of reinforced concrete structure built on January 1, 1965, the lub roof, the 1st underground floor, the 3rd floor above ground, and the total floor area of 375m24m2.

B. On December 11, 2014, the Plaintiffs concluded a sales contract to purchase the instant land and buildings from the Defendant for KRW 1,475,00,000 (Evidence 1; hereinafter “instant sales contract”).

C. On March 27, 2015, the Plaintiffs paid the full purchase price under the instant sales contract, and completed the registration of transfer of ownership (each one-half share) in the name of the Plaintiffs on the instant land.

[Reasons for Recognition] Gap evidence Nos. 1, Eul evidence Nos. 1 to 4 (including each number), the purport of the whole pleadings

2. Determination as to the plaintiffs' claims

A. Since the purchase price of this case was determined based on KRW 18,50,000 for the purchase price as of the average price of KRW 18,50,000, the sale price of this case constitutes “sale designated by quantity” as stipulated in Article 574 of the Civil Act. Since 4.5 square meters among the land of this case (80 square meters) is used as the site by the owner of next building, etc., and 3.5 square meters is confirmed to be lacking in total eight square meters due to the overlap between neighboring land and ownership, pursuant to Articles 574 and 572(1) of the Civil Act, the Plaintiff sought a reduction of KRW 148,00,000 for the purchase price of this case corresponding to the shortage in quantity among the purchase price of this case ( KRW 18,50,000 for the average price of KRW 18,500 x 8 square meters). As such, the Plaintiff suffered damages from adding KRW 51,120,000 for new building construction cost, etc.

B. (i) the provision of Article 574 of the Civil Code is stipulated for determination.