1. All of the plaintiffs' claims are dismissed.

2. The costs of lawsuit are assessed against the plaintiffs.

1. Basic facts

A. On November 12, 2004, the Seocho-gu Seoul, and the Seocho-gu, Seoul, and the 122-household apartment complex, the use of which was approved on November 12, 2004, are three apartment complexes with a total of 122 households, and the Defendant owned the above apartment G G unit (hereinafter “the apartment of this case”).

B. On March 16, 2018, the Defendant leased the instant apartment to Nonparty I. However, around March 16, 2018, the number of water leakages occurred around the lower floor of Jho-ho and K, and the toilet around the toilet. As a result of the detection of water source, the Defendant replaced the instant apartment boiler according to Naom’s diagnosis that there was a cause for the stoves of the individual heating boiler of the instant apartment, and there was no water leakages in the instant apartment after the replacement of the said boiler.

(c)

On June 17, 2019, the Defendant entered into a sales contract with the Plaintiffs for the purchase price of KRW 1.85 billion (hereinafter “instant sales contract”) and completed the registration of the transfer of ownership against the Plaintiffs on August 16, 2019.

A certified intermediary who arranged a sales contract at the time of the sale and purchase of this case directly visited the apartment of this case two times with the plaintiffs and confirmed the status of the apartment, but there was no water leakage, and it was confirmed by the lessee I who had resided at the time that there was no inconvenience in facility defects or dwelling.

(d)

On October 24, 2019, the water leakage from the apartment of this case occurred around Jho Lake, which is below the lower floor. As a result, the plaintiffs requested the pipe, heating and cooling construction (business L) to detect and repair the water source, and as a result, the diagnosis that the cause of waterproof damage caused by the deterioration of the toilet inside the apartment of this case was caused by Naom, the removal of the wall side walls of the toilet inside the instant apartment of this case, and then the removal of the wall side of the toilet outside the instant apartment of this case, and then the removal of the wall side of the bathing toilet of this case.