1. The Plaintiff, Defendant School Construction Co., Ltd., 304,199,889, and Defendant School Construction Mutual Aid Association, are Defendant School Construction.

1. Basic facts

A. The Plaintiff as the Plaintiff (the Korea National Housing Corporation was at the time of construction, and the said Korea National Housing Corporation was merged with the Plaintiff on October 1, 2009 pursuant to Article 7 of the Addenda to the Korea Land and Housing Corporation; hereinafter “Plaintiff”) newly built the 7-dong 704 households of the Cheongju-si 295 Land and Housing Corporation (hereinafter “the apartment of this case”) under the Cheongju-si 295 Land and Housing Corporation (hereinafter “the apartment of this case”), and leased it as a public rental apartment for five years after receiving a pre-use inspection on November 17, 2003, and sold it for sale from January 1, 2009.

B. On September 10, 2001, the Plaintiff entered into a contract for construction works and a contract for the repair of defects (hereinafter “Defendant School Construction”) with Defendant School Construction Co., Ltd. (hereinafter “Defendant School Construction”).

2) Of the construction works of the instant apartment, the construction works of construction machinery and civil engineering works (hereinafter “instant construction works”).

At the time of the above contract, the non-party General Construction Co., Ltd. was awarded a contract. At the time of the above contract, the non-party General Construction Co., Ltd. guaranteed the plaintiff the repair of the defects in the above construction work of the defendant School Construction Co., Ltd., and the defendant Construction Co., Ltd. guaranteed the plaintiff the repair of the walls and columns until December 13, 2013. Among them, the defects in the walls and columns were up to December 13, 2008, until December 13, 2006, until December 13, 2006, the defects in the roof and waterproof construction work were up to December 13, 2005, until December 13, 2005, until December 13, 2005, and until December 13, 2004, the remaining defects in the part of the construction work were newly constructed by the defendant Construction Co., Ltd., Ltd. (hereinafter referred to as the "non-party 26, 2002.