1. The Defendant (Counterclaim Plaintiff) paid KRW 3,685,101 to the Plaintiff (Counterclaim Defendant) and its related amount from October 23, 2016 to October 10, 2018.

1. Basic facts

A. On July 29, 2016, C on behalf of the Plaintiff entered into a contract with the Defendant for remodeling construction works for the fifth floor housing among the building for the building for the building for the building for the building for the building for the building for the building for the building of the building for the building for the building of the building for the ground owned by the Defendant (hereinafter “instant construction works”) (hereinafter “instant construction contract”). From August 2, 2016 to September 2, 2016, the construction period was set as KRW 35,00,000 (excluding value-added tax) and the contract for construction (hereinafter “instant construction contract”).

B. On October 22, 2016, the Plaintiff completed the instant construction work.

[Ground of recognition] The fact that there is no dispute, Gap's evidence No. 1, and the purport of whole pleading

2. Determination on the main claim

A. According to the above facts, barring special circumstances, the Defendant is obligated to pay the Plaintiff the remaining construction cost of KRW 10,000,000,000, computed by subtracting the Plaintiff from the construction cost of KRW 35,000,000, the Plaintiff was already paid, and the delay damages therefrom.

B. 1) The Plaintiff’s assertion on the claim for the additional construction cost was carried out at the Defendant’s request, and as such, the Defendant is obligated to pay the Plaintiff the above additional construction cost of KRW 5,400,000 and damages for delay thereof. 2) The Plaintiff’s assertion was carried out the additional construction cost of KRW 5,400,000, which had no content of the original contract.

Even if there is a separate agreement between the contractor and the contractor on the execution of the additional construction and the payment of the additional construction cost, the contractor’s claim for the additional construction cost shall be recognized.

However, in light of various circumstances revealed in the pleadings, such as that the contents of the instant construction contract or the details of additional construction claimed by the Plaintiff are unclear, that the Plaintiff’s statement of additional construction works is merely a unilateral document prepared by the Plaintiff itself, and that there was no evidence to prove or consent to the Defendant regarding the implementation of the additional construction works or the payment of additional construction costs.