The costs of appeal are assessed against the plaintiffs.

1. As to the ground of appeal No. 1, it is recognized that the seller’s default liability or warranty liability in the apartment sale contract is recognized in cases where an apartment unit sold in lots does not meet the ordinary quality or quality that it should meet the transaction standards, such as housing construction standards under the Housing Act (see Supreme Court Decision 2007Da9139, Apr. 29, 2010). The lower court determined that the apartment unit of this case was a design and construction at a level below 1.25 m-1.5m compared to the road of this case, but it cannot be readily concluded that the apartment of this case is defective merely because the apartment unit of this case was constructed less than the road of this case, because it did not meet the expectation or expectation of the plaintiffs, who are the buyers, due to the above high height and low construction of the apartment unit of this case.

In light of the above legal principles and records, the above judgment of the court below is just, and there is no error of incomplete deliberation, omission of judgment, or misapprehension of legal principles.

2. The ground of appeal No. 2 is merely a duty to notify the other party in advance of such circumstances in light of the principle of good faith, only when it is evident in light of the empirical rule that the other party to the transaction would not have been notified of certain circumstances in real estate transactions.

(2) The court below's decision is just, and there is no error in the misapprehension of the legal principle as to whether the defendant did not notify the above facts in violation of the principle of good faith, even though the difference in the apartment of this case is an important content of the sales contract of this case, and it is obvious that the plaintiffs did not enter into the sales contract of this case in light of the rule of experience of general transactions. Thus, the court below's decision is justified and it is so decided as per Disposition by the assent of all participating Justices.