All appeals are dismissed.

The costs of appeal are assessed against the Plaintiffs, including the part resulting from the supplementary participation.

The grounds of appeal are examined (to the extent of supplement in case of supplemental appellate briefs not timely filed).

1. Regarding ground of appeal No. 1

(a) In order for a defective administrative disposition to be void as a matter of course, it must be objectively apparent that the defect is a serious violation of the important part of the law and is objectively apparent, and when determining whether the defect is significant and obvious, it is required to examine the purpose, meaning, function, etc. of the law and, at the same time, to reasonably consider the specificity of the specific case itself.

In a case where an administrative disposition was taken by an administrative agency by applying a provision of a certain legal relationship or fact in applying a certain Act, the legal doctrine clearly stating that the provision of the Act is not applicable to such legal relation or fact, and thus, if an administrative agency takes the disposition by applying the above provision, even though there is no room for dispute over such interpretation, the defect is grave and obvious. However, in a case where there is room for dispute over the interpretation of the provision of the Act as to the legal relation or fact, the legal principles that the provision of the Act is not applicable to such legal relations or fact clearly revealed, and thus, it cannot

(see, e.g., Supreme Court Decision 2012Du3743, Nov. 29, 2012). B.

The court below held that ① A apartment (hereinafter “instant apartment”) and B shopping mall (hereinafter “instant shopping mall”) were constructed upon approval of a single business plan around September 18, 1979 under the Housing Construction Promotion Act, and ② the Intervenor joining the Defendant applied for authorization to establish the instant shopping mall site in the state of excluding it from the business area without filing a claim for division of land. The Defendant accepted the above application and approved the establishment of the association on September 22, 2003.