1. All of the plaintiffs' claims are dismissed.

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

1. The Construction of the Master Housing Construction Co., Ltd. (hereinafter referred to as the “Comprehensive Housing Construction”) asserted by the plaintiffs is the truster who entrusted B apartment (hereinafter referred to as the “instant apartment”) located in Jung-gu Incheon Metropolitan City with the Korea Asset Trust Co., Ltd. (hereinafter referred to as the “Korea Asset Trust”) by concluding a management-type land development trust contract. The Defendant Asset Trust is the business entity that constructed and sold the instant apartment, and the Defendant U.S. Construction Co., Ltd. and the U.S. Industrial Development Co., Ltd. are the constructor of the instant apartment. The Defendants, as the seller of the instant apartment, concluded each supply contract with the Plaintiffs on the instant apartment.

On the other hand, some of the plaintiffs entered into a balcony expansion contract on the apartment of this case with Defendant Master Construction Company.

In the construction and sale of the apartment of this case, the defendants had defects in the apartment of this case by arbitrarily changing the same differently from the design drawing at the time of approval of the project, failing to construct the part to be constructed in accordance with the design drawing, or failing to perform the defective construction.

The Plaintiffs, as co-owner of the instant apartment, seek a warranty against the Defendants, who are the buyers of the instant apartment pursuant to Article 9(1) of the Act on the Ownership and Management of Aggregate Buildings and Articles 667 through 671 of the Civil Act, against the defects arising from the instant apartment.

2. We examine the judgment, and Article 9 of the Act on the Ownership and Management of Aggregate Buildings provides that the provisions of Articles 67 through 671 of the Civil Act on the contractor's liability for warranty shall apply mutatis mutandis to the warranty liability of the person who constructs and sells the aggregate building in order to induce the builder or seller of the aggregate building to form a solid building and to further protect the owner of the defective aggregate building.