The plaintiff is an autonomous management body that consists of the occupants in order to manage the six and 203 households of A Apartment (hereinafter referred to as "the apartment of this case") located in Si-Sti City, B.

On October 20, 2006, AE Development Co., Ltd. conducted the new construction and sale business of the instant apartment from November 1, 2006 with the approval of the business plan, and on December 31, 2008, when the above company no longer is able to proceed with the said business, the Defendant (the change of the name of the Defendant from the Korea Housing Guarantee Co., Ltd. in accordance with Article 4 of Addenda of Housing and Urban Fund Act, July 1, 2015) who entered into a sales guarantee contract with respect to the said business, upon the request of buyers, became liable under the sales guarantee contract.

In addition, the defendant entered into a warranty contract with the presentjin Co., Ltd., the contractor of the apartment of this case as follows.

The fact-finding Co., Ltd. entered into the warranty contract of this case with the defendant as the warranty creditor of the apartment of this case as the Si interest market, and entered into the warranty contract of this case (hereinafter referred to as the "the present warranty contract of this case") and deposit it with the Si interesting City Mayor after obtaining each warranty bond from the defendant.

Each of the above warranty warranty bonds, the insurance period of the No. 1 insurance period of the instant apartment construction (house) from February 1, 2010 to January 31, 2015, stating that the guarantee creditor shall not be liable for any defect incurred before the guarantee period, from February 1, 2010 to January 31, 2015, and each of the warranty bonds, from February 1, 2010 to January 31, 2015, from February 1, 2010 to January 31, 2020, shall not be liable to guarantee the warranty for the defect that occurred before the guarantee period, and the guarantee creditor shall be deemed to be changed to the same council of occupants' representatives.

The usage inspection of the apartment of this case and the defect repair company of this case had undergone a pre-use inspection on the apartment of this case from the Si interest market on February 22, 2010, and the plaintiff was formed on September 4, 2014, and around that time.