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

2. The costs of appeal are assessed against the Plaintiff.

Basic Facts

In the process of voluntary auction, the Plaintiff purchased Seongbuk-gu Seoul Metropolitan Government Clla Da non-01, which is a multi-household, and acquired ownership on April 16, 2015.

The defendant purchased the above CBC 201 at the voluntary auction procedure and acquired the ownership on May 14, 2015.

The plaintiff's loan is located above the upper floor of D's 101, and the defendant's loan is located above the upper floor, and the defendant's loan is on the rooftop.

The Plaintiff’s damage caused by water leakage 101 and D’s loan 101, the Plaintiff asserted that the damage was caused by water leakage occurred in the Defendant’s loan 201, and the Plaintiff filed the instant lawsuit, and D transferred its damage claim, etc. against the Defendant to the Plaintiff on July 1, 2016.

[Ground of recognition] 1 to 4 and 12 of each description or image (including numbered items; hereinafter the same shall apply) and a claim for damages as to the cause of a claim as a whole of the pleadings, the Defendant alleged that the Defendant delayed repair with knowledge of the leakage under 201, thereby causing damage due to water leakages of the Plaintiff and D 101.

The plaintiff paid KRW 2.74,00 to the recovery cost of water leakage damage under f01, and KRW 1.260,000 to the D-owned 101,00 won in light of the expenses paid by the plaintiff.

On the other hand, since D transferred its damage claim to the Plaintiff, the Defendant is obligated to pay the Plaintiff the total amount of KRW 4,000,000 and the delay damages as compensation for damages caused by defects in the establishment and preservation of the structure.

Judgment

D’s act of transferring the damage claim against the Defendant against the Plaintiff by the owner of No. 101, the part of the damage claim against the Plaintiff No. 101, the Plaintiff’s act of transferring the damage claim against the Defendant ought to be deemed null and void without any special reason, among the Plaintiff’s damage claim, since it is deemed null and void.