The judgment below

The part against the defendant is reversed, and that part of the case is remanded to the Seoul High Court.

The grounds of appeal are examined.

1. With respect to the grounds of appeal Nos. 1 and 2, if a person subject to the relocation measures and a supplier of a housing site or housing entered into a special supply contract with the person subject to the relocation measures, including the cost of the basic living facilities under Article 78(4) of the former Act on the Acquisition of Land, etc. for Public Works and the Compensation therefor (amended by Act No. 8665 of Oct. 17, 2007; hereinafter “former Public Works Act”) in the sale price and thus the person subject to the relocation measures paid the cost of the basic living facilities to the project operator, etc., the portion of the special supply contract that included the cost of the basic living facilities in the sale price in the sale price of housing site or housing is null and void, as it violates Article 78(4) of the former Public Works Act

(See Supreme Court en banc Decision 2007Da63089, 63096 Decided June 23, 2011). In light of such legal doctrine, if the Defendant, as a project operator, entered into a special supply contract with the person subject to relocation measures, includes the cost of basic facilities in the supply price calculated on the basis of the cost of the housing site formation, then the Defendant’s unjust enrichment should be deemed established. The supply price of the housing site does not reach the cost of the housing site. In such a case, the cost of basic facilities installed on the basis of the supply price of the housing site equivalent to the appraisal price should not be calculated.

(see, e.g., Supreme Court Decision 2012Da93435, Oct. 11, 2013; Supreme Court Decision 2012Da59268, Oct. 17, 2013). Therefore, insofar as the sale price of the instant housing site includes the cost of basic living facilities in the sale price of the instant housing site, the part that included the cost of basic living facilities, regardless of whether the sale price does not reach the cost of the housing site development in the instant project district, shall be governed by the former Public Works Act, which is a mandatory law.