A. Defendant Y Housing Redevelopment and Rearrangement Project Association (hereinafter “Union”) is a housing redevelopment and rearrangement project association that obtained authorization for the establishment of a housing redevelopment and rearrangement project association with a size of 61,795 square meters located in the area of project in Busan Seo-gu, Busan Metropolitan City (hereinafter “the head of the Gu”) in order to implement a housing redevelopment project, and the Plaintiffs are owners of land, etc. in the area of project.

B. Establishment (1) On November 2, 2015, the promotion committee for the Y Housing Redevelopment and Improvement Project Association was approved by the head of the Gu of the defendant for the establishment of a project implementation district.

(2) On December 20, 2006, the Mayor of Busan Metropolitan City designated a rearrangement zone as a public announcement of Busan Metropolitan City on the project implementation district.

(3) Upon receiving the written consent from the owners of lands, etc. to establish an association on December 20, 2006, the promotion committee applied for authorization to establish an association from the owners of lands, etc. on December 20, 2006. On January 19, 2007, the head of the Defendant: (a) calculated on January 19, 2007 that 305 persons among the total 374 owners of lands, etc. consent to establish an association (the consent rate of 81.5% and the small number of less than four decimals; hereinafter the same shall apply) and calculated that 305 persons consent to establish an association (the consent rate of 81.5%; hereinafter the same shall apply) the former Act on the Maintenance and Improvement of Urban Areas and Dwelling Conditions for Residents (amended by Act No. 8785, Dec. 21, 2007; hereinafter “former Act”). (hereinafter “instant authorization disposition”).

C. (1) On August 5, 2008, the Defendant Union obtained the approval of the project implementation plan from the head of the defendant's office on August 5, 2008, and the approval of the project implementation plan was publicly notified as AB on August 13, 2008.

The defendant association received the application for parcelling-out from the owner of land, etc. by applying for parcelling-out from August 13, 2008 to September 21, 2008.

(2) On June 8, 2012, the Defendant Union obtained the approval of the project implementation plan from the head of the Gu.