1. All of the plaintiffs' claims are dismissed.

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

1. Basic facts

A. The Korea National Housing Corporation (Korea Land Corporation and the Korea National Housing Corporation were merged with the defendant on October 1, 2009; hereinafter “the defendant”) was designated as the “D Housing Site Development Project zone” under the Housing Site Development Promotion Act, and the Korea National Housing Corporation (the Korea Land Corporation and the Korea National Housing Corporation were merged with the defendant on October 1, 2009; hereinafter “the defendant”) was approved on January 5, 2002.

B. As the Defendant was incorporated into the instant project zone, the person selected as a person subject to relocation measures as part of the relocation measures for the residents who lost their base of living due to expropriation of the owned housing or land, etc., was specially sold the land for detached housing in the instant project zone.

C. According to the aforementioned relocation measures, the Plaintiffs succeeded to the rights and obligations under the sales contract from the parties who concluded the sales contract for the land for detached housing in the instant project district with the Defendant (hereinafter “instant sales contract”).

The Plaintiffs paid the sales price under each sales contract of this case in full.

[Ground for Recognition: Facts without dispute, Gap evidence 1 through 3, Eul evidence 7, the purport of whole pleadings]

2. The plaintiffs' assertion that the defendant sold the land for detached houses to the plaintiffs as part of the relocation measures under Article 78 of the former Act on Acquisition of and Compensation for Land, etc. for Public Works (amended by Act No. 8665 of Oct. 17, 2007, hereinafter "former Public Works Act"). Thus, the defendant bears the burden of installing basic living facilities pursuant to Article 78 (4) of the former Public Works Act, which is a mandatory provision.

Nevertheless, since the plaintiffs paid the sale price including the cost of installing the basic living facilities, the defendant must return the amount equivalent to the cost of installing the basic living facilities to the plaintiffs as unjust enrichment.

(However, only a part of the unjust enrichment shall be claimed). 3. A.