A. The Plaintiff owns and occupies the Yongsan-gu Seoul Metropolitan City C Apartment E (hereinafter “Plaintiff apartment”) and the Defendant owns and occupies the above-story D apartment (hereinafter “Defendant apartment”).

B. On January 18, 2018, the Plaintiff discovered water leakage in the central part of the fire extinguishing unit of the Plaintiff apartment apartment site, and discovered water leakage damage to the management office.

C. The management office visited the Plaintiff’s apartment and the Defendant’s apartment and confirmed the site, and notified the Defendant of the result. The Defendant entrusted the water leakage detection business entity to conduct a water leakage inspection, and then performed the Defendant’s toilet waterproof construction work.

On the other hand, as the defendant mentioned the possibility that the above water leakage occurred due to the defect in the common area of apartment, the plaintiff requested the apartment management office to confirm whether there is a defect in the outer wall part of apartment common area. The president of the Dong representative of the apartment's council of occupants' representatives, who sent the text message to the plaintiff on April 6, 2018, knew that there is no defect such as the crack of the outer wall of apartment.

E. On January 8, 2019, the Plaintiff became aware of the damage inflicted on the Defendant of the apartment management office and the Defendant, as the water leakage occurred again on the central fire reduction unit of the Plaintiff apartment site.

F. The schedule of the civil petition for household prepared by the management office at the time includes the following: “The heating is not the same as the Defendant’s door-to-door visit and confirmation of apartment, which is not the same as the heating system. The booms in which the booms, which were put into the bottom of the outer wall of the Washington, are seriously milched, and there was such phenomenon in the middle of a year.”

The plaintiff apartment floor plan of the apartment of the defendant was confirmed by the height of the wall of the defendant apartment surface plan and determination, and the cause of occurrence-B-3-4: Washington was established, so it was not possible to confirm whether the apartment surface plan of the defendant was singing down and sing down all sections. However, it was established at the lower single.