1. The plaintiff's claim is dismissed.

2. The costs of lawsuit shall be borne by the Plaintiff.

Comprehensively taking account of the purport of Gap evidence Nos. 1 and Eul evidence Nos. 1 and the purport of the whole arguments and arguments, it may be acknowledged that the plaintiff was subcontracted with the defendant on September 26, 2014 by determining that the key construction cost of KRW 49,50,000 for the construction period, from September 26, 2014 to October 31, 2014, and the progress payment was paid within 30 days from the date of receipt of the object, and that the building of this case was approved for use on November 28, 2014. Thus, the defendant is liable to pay the plaintiff the subcontract price of KRW 49,50,000 for the construction cost of the building and the delay payment thereof to the plaintiff, barring any special circumstance.

In regard to this, the defendant's defense that the above claim for the construction price had expired by prescription is examined, and the above claim for the construction price was due from November 28, 2014 to December 28, 2014, which was later than 30 days after the date when the use of the building of this case was approved, and it is apparent that the plaintiff's lawsuit of this case was filed on June 19, 2018, which was later than 3 years after the expiration of the statute of limitations as stipulated in Article 163 subparagraph 3 of the Civil Act, since the above claim for the construction price had already expired by prescription prior to the filing of the lawsuit of this case, the defendant's defense is justified.

Therefore, the plaintiff's claim is dismissed as it is without merit. It is so decided as per Disposition.