[2] In a case where the executor of a public project included the basic cost of living facilities under Article 78(4) of the former Act on the Acquisition of Land, etc. for Public Works and the Compensation Therefor in the sale price under a special supply contract for a resettled housing site which was entered into with a person subject to relocation measures, whether such part is invalid because it violates the mandatory law (affirmative)

[3] In the event that the actual sale price does not reach the cost of the housing site development by discounting a certain amount from the cost of the housing site development, the standard for determining whether the cost of the housing site development includes the cost of the basic living facilities in the sale price, and whether only the portion exceeding the “amount obtained by deducting the cost of the basic living facilities from the cost of the housing site development” among the sale price constitutes unjust enrichment as the cost of the basic living facilities installation included in the sale price (affirmative)

[4] The method of calculating "amount calculated by deducting the cost of basic living facilities from the cost of creating the housing site / Where calculating unjust enrichment equivalent to the cost of basic living facilities included in the sale price of the unsettled housing site, whether the project operator should be the basis for the actual cost of the cost of creating the housing site, which is used as the basis for the determination of the sale price of the unsettled housing site (affirmative)

[5] The requirements and scope of the cost of housing site development to be included in the cost of basic living facilities and the burden of proof (=person claiming that the cost of basic living facilities is the cost of basic living facilities)

[6] Whether wastewater treatment facilities under Article 48(1) of the former Water Quality and Aquatic Ecosystem Conservation Act are included in basic living facilities under Article 78(1) and (4) of the former Act on Acquisition of and Compensation for Land, etc. for Public Works Projects (negative in principle)

1. Of the plaintiffs, the remaining grounds of appeal except for plaintiffs 74, 75, 76, 77, 78, and 79

Where a project operator separately determines the sale price of a resettled housing site by applying a gap within the discretionary scope, the development cost of the entire resettled housing site may be deemed to have been differentiatedly allocated to each resettled housing site in accordance with the conditions of the location. Therefore, when calculating the development cost, basic living facilities installation cost, and the reasonable sale price based on the cost of each resettled housing site, the relevant gap shall be calculated (see, e.g., Supreme Court Decisions 2014Da6572, Aug. 20, 2014; 2014Da11406, Aug. 20, 2014; 2016Da231556, Aug. 30, 2018).

In light of the relevant legal principles and records, it is reasonable that the court below calculated the gap rate applied by the defendant when calculating the selling price in order to calculate the unjust enrichment, and there is no error of misapprehending the legal principles on the application of the gap rate.

2. As to the Defendant’s ground of appeal

A. Ground of appeal No.1

If a person subject to relocation measures was to pay the project operator the cost of installing basic living facilities as stipulated in Article 78(4) of the former Act on Acquisition of and Compensation for Land, etc. for Public Works (amended by Act No. 8665, Oct. 17, 2007; hereinafter “former Public Works Act”) to the project operator by including the cost of installing basic living facilities in the sale price under a special supply contract for the housing site for the migrants entered into between the person subject to relocation measures and the project operator, the part that included the cost of installing basic living facilities in the sale price under a special supply contract is null and void in violation of Article 78(4) of the former Public Works Act, which is a mandatory law (see Supreme Court en banc Decision 2007Da63089, 63096, Jun. 23, 2011).

In a case where the sale price does not reach the cost of creating a housing site by discounting a certain amount at the cost of creating a housing site, the entire cost of installing basic living facilities, which is a part of the cost of creating the housing site, shall not be deemed to have been included in the sale price. Whether the sale price exceeds the “amount obtained by deducting the cost of installing basic living facilities from the cost of creating the housing site” and whether the cost of installing basic living facilities is included in the sale price and the scope included therein should be determined. Therefore, if the sale price exceeds the “amount obtained by deducting the cost of installing basic living facilities from the cost of developing the housing site” in the sale price, only such portion constitutes unjust enrichment as the cost of installing basic living facilities included in the sale price (see Supreme Court Decisions 2013Da29509, Jul. 23, 2015; 2014Da8997, Oct. 15, 2015).

With respect to the portion not exceeding 330 square meters among the multi-resident housing sites, the lower court ordered the Defendant to return the said amount to the Defendant by calculating the amount of unjust enrichment by calculating the amount exceeding the lawful parcelling-out price calculated as above among the Plaintiffs’ sales price with respect to the portion not exceeding 330 square meters in excess of 330 square meters of the previous housing site by calculating the lawful sales price in the formula of “total project cost (excluding the expenses for relocation measures) 】 sales

In this case where the Defendant set the sale price of a housing site at a certain amount at the cost of housing site development, the aforementioned calculation method of the lower court is justifiable as it calculated by unjust enrichment for the expenses corresponding to the cost of installing basic living facilities included in the sale price of a housing site (see Supreme Court Decision 2012Da4770, Nov. 14, 2013). In so doing, contrary to what is alleged in the grounds of appeal, the lower court did not err by misapprehending the legal doctrine on the calculation of unjust enrichment

B. Ground of appeal No. 2

Article 78(4) of the former Public Works Act prohibits a project operator from paying the cost of the basic facilities to a person subject to the relocation measures, but does not stipulate the details of the cost of the basic facilities to be borne by the person subject to the relocation measures or the cost of the sale price to be received from the said person. Thus, among the cost of the construction of the housing site that the project operator actually used as the basis for the determination of the cost of the sale of the housing site for the actual migrants, the "amount obtained by deducting the cost of the basic facilities from the cost of the construction of the housing site" should be calculated by deducting the cost of the construction of the housing site from the cost of the construction of the housing site. Unlike this, the cost of the construction of the housing site that can be borne by the person subject to the relocation measures shall not be deemed to be the basis for the determination of the cost of the sale of the housing site to be used as the basis for the calculation of the cost of the housing site to be included in the cost of the construction of the housing site below the development cost. Therefore, it cannot be deemed that the total cost of the housing site should be calculated based on Article 788(4).

Nevertheless, the lower court calculated the “amount obtained by deducting the basic facilities installation cost from the cost of housing site development cost” in comparison with the sale price, by including the facilities maintenance cost and other public facilities installation cost in calculating the cost of housing site development based on the Defendant’s determination of the sale price of the unsettled housing site, and by including the facilities maintenance cost and other installation cost in the area of the comprehensive sports site excluding the area of the comprehensive sports facility site from the cost of housing site development cost, unlike the area of the complex development cost.

The judgment of the court below on this part is erroneous in the misapprehension of the legal principles as to the calculation of the cost of housing site development or the cost of supply, which affected the conclusion of the judgment. The ground of appeal assigning

C. Ground of appeal No. 3

(a) The area of roads corresponding to basic living facilities;

In light of the relevant legal principles and records, the court below is just in calculating the cost of installing basic living facilities including the total area of the road in the judgment of the court below in the project district of the Multifunctional Administrative City construction project (hereinafter “the project in this case”) by deeming the entire road area in the project district of this case as a basic living facility (see Supreme Court Decision 2015Da206379, Jun. 15, 2018). Contrary to the allegations in the grounds of appeal, the court below did not err by misapprehending the legal principles on the scope of basic living facilities

(b) Traffic squares;

As seen earlier, the lower court is justifiable to have determined that the area of a traffic plaza, which is the intersecting point of the roads established in the project district, is also included in the construction area of the basic living facilities. In so doing, contrary to what is alleged in the grounds of appeal, the lower court did not err by misapprehending the legal doctrine on the scope of the basic living facilities.

(iii) drainage stations and water purification stations;

Water supply facilities and water supply pipes constitute basic living facilities essential for the lives of residents in a project district (see, e.g., Supreme Court Decisions 2012Da59268, 59275, 59282, Oct. 17, 2013; 2015Da1291, 1307, 1314, etc.).

In the same purport, the lower court is justifiable to have determined that the area of the drainage place and the water purification place is included in the installed area of the basic living facilities, and contrary to what is alleged in the grounds of appeal, the lower court did not

(iv) sewage terminal treatment plants;

Sewage terminal treatment is a water supply and sewerage-related facility that is essential for the lives of residents in a project district (see Supreme Court Decision 2014Da43472, 43489, Oct. 15, 2014, etc.).

In the same purport, the lower court is justifiable to have determined that the area of sewage terminal treatment plant is included in the installation area of basic living facilities, and contrary to what is alleged in the grounds of appeal, there were no errors by misapprehending the legal doctrine on

(v) Water pollution prevention facilities;

A) The lower court recognized the site cost of water pollution prevention facilities as the cost of establishing basic living facilities by deeming that the area of water pollution prevention facilities is included in the construction area of basic living facilities.

B) However, it is difficult to accept the above determination by the lower court for the following reasons.

Of the cost of housing site development, the cost of the item appropriated for the cost of housing site development is recognized to be related to the cost of construction of basic living facilities, i.e., the cost of the cost of construction of basic living facilities, but the cost of construction of basic living facilities within the ratio of the cost of construction of basic living facilities to the total or total project area. The cost of construction of basic living facilities is included in the cost of construction of basic living facilities, and the burden of proof of such relevance is asserted that the cost of construction of basic living facilities is the cost of construction of basic living facilities (Supreme Court Decision 2014Da8

Meanwhile, wastewater treatment facilities under Article 48(1) of the former Water Quality and Aquatic Ecosystem Conservation Act (amended by Act No. 13879, Jan. 27, 2016; hereinafter “former Water Quality Ecosystem Act”) are, in principle, facilities installed and operated to treat and discharge water pollutants discharged from “each place of business,” and all or part of the expenses incurred in the installation and operation thereof are borne by the person who caused the occurrence of the occurrence. Thus, it cannot be deemed that such wastewater treatment facilities are included in basic living facilities under Article 78(1) and (4) of the former Public Works Act (see Supreme Court Decision 2014Da34812, Oct. 13, 2016).

However, according to the records, it is not clear whether the water pollution prevention facilities of this case are installed in accordance with the relevant provisions of the former Water Quality Ecosystem Act, and it is also unclear whether the actual function of the water pollution prevention facilities is to treat and discharge water pollutants discharged from each workplace. Thus, if the water pollution prevention facilities of this case actually function as sewage terminal treatment or both functions as sewage terminal treatment and sewage terminal treatment, regardless of the name of the water pollution prevention facilities of this case, the part corresponding to sewage terminal treatment facilities can be seen as being included in basic living facilities (see the above Decision 2014Da43472, 43489)

Therefore, the court below should have deliberated on the above matters concerning the water pollution prevention facilities of this case and judged whether the water pollution prevention facilities of this case are basic living facilities. However, the court below erred by misapprehending the legal principles on the scope of basic living facilities and failing to exhaust all necessary deliberations, which affected the conclusion of the judgment.

D. Ground of appeal No. 4

(a) Packing construction cost and street lamps construction cost;

As long as the entire road as indicated in the judgment in the instant project district can be recognized as a basic facility, it shall be deemed that the Defendant’s packing construction cost and street lamps construction cost are included in the construction cost of basic living facilities (see Supreme Court Decision 2012Da9234, Jan. 29, 2014).

In the same purport, the lower court’s determination that the total amount of packing construction cost and street lamps included in the cost of creating basic living facilities is justifiable. In so doing, it did not err by misapprehending the legal doctrine on the scope of basic living facilities, contrary to what

(ii)the cost of the drainage and the cost of the sewage terminal construction;

As seen earlier, the lower court was justifiable to have determined that the cost of the drainage site and the cost of the sewage terminal construction are included in the cost of the basic living facilities. In so doing, the lower court did not err by misapprehending the legal doctrine on the scope of the basic living facilities, contrary to what is alleged in the grounds of appeal.

(iii) final survey costs and appurtenant works costs;

Of the final survey cost and the appurtenant construction cost calculated by the Defendant, the part corresponding to the legitimate ratio of the area of basic living facilities constitutes the installation cost of basic living facilities (see the aforementioned Decision 2012Da59268).

Therefore, we cannot accept the allegation in the grounds of appeal that the part of the final survey cost and appurtenant work cost calculated by the defendant, which corresponds to the legitimate ratio of the area of basic living facilities, does not constitute the installation cost

However, as seen earlier, the lower court erred in its judgment that included the area of water pollution prevention facilities in the installation area of basic living facilities, and thus, the part of the lower judgment that calculated the ratio of basic living facilities among confirmation survey costs and appurtenant construction costs is also erroneous. Therefore, the ground of appeal on this point is with merit.

(iv)each construction cost of bridges, 1, 2, 2, 4, 5, 50,00,000,000,000,000

Inasmuch as tunnels, bridges, underground passages, overpasses, and three-dimensionalization facilities are part of roads (see, e.g., Article 2 subparag. 1 and Article 51 of the Road Act). If roads on which such facilities are installed are installed are basic living facilities, such facilities constituting basic living facilities (see, e.g., Supreme Court Decisions 2015Da21943, Dec. 10, 2015; 2015Da22083, Feb. 18, 2016).

As seen earlier, the entire road installed in the project district of this case constitutes a basic living facility. Therefore, the court below is just in holding that the expenses incurred in installing a bridge 1, 2, underground tea, sidewalk, pedestrian bridge, underground sidewalk, high-priced car, or tunnel are included in the expenses incurred in installing a basic living facility, and contrary to what is alleged in the grounds of appeal, the court below did not err by misapprehending the legal principles as to the scope of a basic living facility.

3. Conclusion

Therefore, the part of the judgment of the court below against the defendant is reversed, and that part of the case is remanded to the court below for a new trial and determination. The remaining plaintiffs' appeals except for plaintiffs 74, 75, 76, 77, 78, and 79 are all dismissed. It is so decided as per Disposition by the assent of all participating Justices on the bench.

Justices Kim Jae-hyung (Presiding Justice)