1. The defendant's appeal and the plaintiff's incidental appeal are all dismissed.

2. Costs arising from an appeal and an incidental appeal shall be respectively.

1. Facts of recognition;

A. The Plaintiff is the owner of Dongjak-gu Seoul Metropolitan Government 25th floor D (hereinafter “instant D”) and the Defendant is the lessee who resides in the said apartment 26th floor E (hereinafter “instant E”).

B. In the balcony of the above apartment, water can not be used in the balcony because of its cover, and in cases where water can not be used in the balcony by installing a washing machine or air-conditioning, etc. it is inevitable to use it by cutting the drain pipe well in the drain pipe, and in cases where water is drained in the balcony because the drain pipe, such as a washing machine, is not used well in the drain pipe, there is a risk of water leakage damage in the apartment of the following floor.

C. On July 3, 2018, the lessee residing in subparagraph D of the instant case discovered the occurrence of water leakage damage (hereinafter “damage to water leakage in this case”) caused by ice and fung in the ceiling and the wall of the small-scale balcony in the instant sub-paragraph D.

On June 22, 2018, the Defendant installed air conditioners in the instant case E. In the process of confirming the cause of water leakage after the damage to water leakage of the instant case occurred, the Defendant used water discharge units, such as laundry machines and air conditioners, without placing them in the drainage outlet, and thereby, confirmed that water was missing.

E. After doing so, the Defendant left the Kakao Stockholm message to the effect that, after putting the above drainage lake into the drainage pipe and using it, no additional water leakage damage occurred, and the part of the water leakage damage under the instant subparagraph D became the part of the water leakage damage, and that, around September 6, 2018, the Defendant left the Kakao Stockholm message to the effect that “in addition, no additional water leakage is available when putting the drainage lake into the drainage pipe” is recognized to the lessee under the instant subparagraph D.

F. Meanwhile, at a time similar to the time when water leakage damage in the instant case occurred, damage to water leakage under the said apartment F also occurred and against the Defendant and the E-owner.