1. The Plaintiff:

A. The defendant Jinjin Co., Ltd., Changjin Construction Co., Ltd., and Gyeongwon Construction Co., Ltd. shall be jointly and severally liable for 260.

1. Basic facts

A. A. On February 207, Defendant Jinjin Co., Ltd. (hereinafter “Yinjin”), Defendant Changwon Construction Co., Ltd. (hereinafter “original Mine Construction”), and Defendant Gyeong Gung Construction Co., Ltd. (hereinafter “Jung Construction,” and the Defendant Co., Ltd. (hereinafter “Defendant Co., Ltd.”) constituted a joint supply and demand organization for the joint construction of the apartment complex of 515 Incheon Songdo 4 Tools, Incheon, 3 Industrial Complex of 515 (hereinafter “the apartment complex of this case”), which is ordered by the Plaintiff, with the T&S Co., Ltd., Ltd., and the Defendant Jin-jin’s representative.

B. On June 29, 2007, the Defendants Co., Ltd. concluded a construction contract with the Plaintiff on June 29, 2007 with the content that the instant apartment is to be constructed in the design and construction package deal method (hereinafter “the instant construction contract”), jointly with the Plaintiff on June 29, 2007, the construction cost of the instant apartment is KRW 68,949,14,000, and the construction period is to be determined from June 29, 2007 to January 14, 2010, and the Defendants Co., Ltd agreed that the Plaintiff, including the warranty liability, shall be jointly and severally liable for the performance of obligations under the instant construction contract against the Plaintiff.

On the other hand, on June 29, 2007, Defendant Construction Mutual Aid Association concluded a defect warranty contract for the instant construction with Defendant Howon Construction and Afforestation Construction, and issued a warranty against defects to the Plaintiff. According to the warranty liability contract, the warranty liability amount for waterproof and roof and Home Works that include heating works is the total amount of KRW 29,019,491, and the total amount of KRW 21,764,618 among them is the warranty amount for Defendant Howon Construction, 7,254,873.

C. The Defendants Company completed the instant apartment construction and obtained approval for use around March 26, 2010.

However, after that, the heating of the apartment itself from the occupants of the apartment of this case.