The plaintiff's appeal and the additional claim in this court are dismissed, respectively.

The plaintiff's litigation costs after the appeal are filed.

1. The reasoning of the judgment of this court citing the judgment of the court of first instance is as stated in the reasoning of the judgment of the court of first instance except for the addition of Paragraph 2 to the additional judgment of the court of first instance, and thus, it is citing the summary thereof pursuant to the main sentence of Article 4

2. Additional determination

A. The Plaintiff’s additional assertion ① In the public announcement of the instant tender, stating that “If a successful bidder fails to conclude a contract within the contract period, the successful bidder shall be invalidated, and the bid bond shall belong to our construction (the Defendant) (hereinafter “the instant bid bond”).”

Since the contract of this case was null and void because the plaintiff, who is a successful bidder, did not enter into a contract, the defendant returned the bid bond to the plaintiff, but the defendant did not return it in accordance with the provisions for attribution of the bid bond

The provision on the reversion of the bid bond of this case has the nature of the liquidated damages, barring any special circumstance, as the agreement for penalty, and it shall be limited to the case where the successful bidder does not conclude this contract without any justifiable reason. However, as in this case, if it is interpreted that the provision on the reversion of the bid bond of this case includes false facts in the contents of the tender announcement of this case and does not proceed to the conclusion of a contract, it is invalid in violation of Articles 6(1), 6(2)1 and 8 of the Act on the Regulation of Terms and Conditions, which unfairly imposes excessive liability

Therefore, the Defendant is obligated to refund to the Plaintiff the amount equivalent to the bid bond reverted to the Plaintiff according to the pertinent provisions on attribution of the bid bond.

② Even if the pertinent provision on the ownership of bid bond is deemed valid, such provision should be mitigated because the estimated amount of compensation for damages is unreasonable and excessive.

③ Article 3 of the Act on Fair Labeling and Advertising through the Public Notice of this case.