1. All appeals filed by the plaintiffs are dismissed.

2. The costs of appeal are assessed against the Plaintiffs.

Purport of claim and appeal

1.

1. The reasoning of the court’s explanation concerning this case is as follows, and the reasoning of the judgment of the court of first instance is the same as that of the judgment of the court of first instance, and such reasoning is cited in accordance with the main sentence of Article 420 of the

o No. 7, No. 3 of the judgment of the first instance court, and even the legislative review report (No. 104) at the time of the first establishment of the contents such as Article 22(5) of the former Framework Act on the Construction Industry at the time of the first establishment of the same Act, with respect to the background of the proposed provision, it is difficult for subcontractors to secure legal premiums because the expenses incurred in subscribing to social insurance are generally reflected in general expenses, public expenses or miscellaneous expenses, etc., so it is difficult for them to secure legal premiums, and there is a view to evading the insurance coverage of daily employed workers. Thus, the above provision provides that the expenses related to social insurance shall be specified in the statement of contract amount calculation so that the relevant expenses may be reflected

o. On the second part of the judgment of the court of first instance, Article 22(5) of the former Framework Act on the Construction Industry cannot serve as a basis for claiming payment of the amount equivalent to the social insurance premium of this case against the defendant who is the subcontractor. Thus, since the payment of the price agreed upon by the plaintiffs as the price of construction, it cannot be deemed that there is a transfer of goods without any legal basis in relation to the defendant, since there is no possibility for establishing unjust enrichment."

o No. 11, No. 3 of the judgment of the first instance court. The issue of whether the prime contractor unilaterally determines the subcontract price according to a low unit price, whether the subcontract price is decided by the voluntary consent of the subcontractor, etc. shall be the extent of the superior position of the prime contractor against the subcontractor, the existence of the subcontractor's transaction to the prime contractor, the continuity of the transaction, the characteristics of the transaction, and the market situation.