1. The judgment of the first instance, including the claim of the Plaintiff (Appointed Party) expanded by this court, is as follows.

1. Basic facts

A. The plaintiffs are married couple, and they are co-owners holding 1/2 shares in relation to C Apartment No. 104 Dong 1703 (hereinafter “instant No. 1703”), each of which is located on the ground of Yongcheon-si D and one parcel (hereinafter “instant No. 1703”), and reside in the instant case No. 1703.

B. The defendant is an organization composed of representatives from each Dong elected by the occupants for the management of 329 households, four apartments.

C. The instant 1703 is a household located on the top floor, and the C Apartment 104 rooftop (hereinafter “instant rooftop”) which is directly connected to the Dasle door (hereinafter “instant rooftop”) consists of the Plaintiffs’ exclusive ownership partitioned by the hedges and the remaining common areas managed by the Defendant.

From early 2015, the Plaintiffs confirmed the changes in the color of the natural remote areas suspected of being leaked in accordance with the instant 1703, and notified the Defendant on April 20, 2015.

E. On April 27, 2015, the Defendant performed waterproofing construction works on the instant rooftop. Nevertheless, the number of water leakages continuously occurred under the instant case’s 1703, and on September 7, 2015, on the instant rooftop, the Defendant carried out maintenance and repair works using a construction method that stuffs a plaque (a auxiliary device that serves as a passage to enter index systems) with the Plaintiffs’ exclusive part among the instant rooftops, and injects the index system (materials used to prevent water leakage).

F. On November 28, 2015, the Plaintiffs paid KRW 1,600,000 to E, which is a water detection business entity, and requested a water leakage inspection. On December 11, 2015, the Plaintiffs received a water leakage inspection.

G. On January 8, 2016, the Plaintiffs sent to the Defendant a content-certified mail to the effect that a continuous leakage occurred under the instant 1703.

H. On March 10, 2016, the Defendant performed waterproof construction on the entire rooftop of the instant case, and thereafter, water leakage did not occur in the instant case No. 1703.

I. Article 33 (3) and (4) of the C Apartment Management Rules provide that "the council of occupants' representatives shall perform the duties and responsibilities of the council of occupants' representatives."