All appeals are dismissed.

The costs of appeal are assessed against each appellant.

The grounds of appeal are examined (to the extent of supplement in case of supplemental appellate briefs not timely filed).

1. Plaintiff’s ground of appeal

A. The first ground of appeal is that the construction is not completed if the last process intended to be interrupted during the proceeding is not completed, and the construction is completed even the last process scheduled to be completed and its main text is that the construction is not completed.

Although the parts of the structure have been constructed as agreed and completed by social norms, it should be interpreted that the construction has been completed if it is required to make compensation due to incomplete defects.

Whether the last process of construction is terminated or not shall be determined objectively in light of the specific contents of the relevant construction contract and the good faith principle, rather than the contractor’s assertion or the contractor’s completion inspection. Such standards also apply to the agreement on compensation for delay, which has the nature of as liquidated damages for delay of the contractor’s completion of the work (see, e.g., Supreme Court Decision 2009Da7212, 7229, Jan. 14, 2010). Based on the adopted evidence, the lower court determined that the Plaintiff was liable to compensate for delay, recognizing that the Plaintiff contracted the instant construction from the Defendant on April 29, 2008; the Plaintiff and the Defendant changed the deadline for completion of the instant construction from December 31, 209 to July 31, 2010; the Plaintiff did not complete the instant construction by July 31, 2010, which is the deadline for completion of the construction; and determined that the Plaintiff was liable to compensate for delay.

The above determination by the court below is in accordance with the legal principles as seen earlier. Contrary to the allegations in the grounds of appeal, there were no errors in the misapprehension of legal principles as to the occurrence of obligation to pay liquidated damages

B. As to the completion date of the construction of the instant case’s construction work, the lower court did not err by misapprehending the legal doctrine on the number of delayed days.