1. The plaintiff's appeal is dismissed.

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

The purport of the claim and appeal is the purport of the appeal.

1. The reasoning of the court's explanation of this case is as follows, except where the plaintiff added '2. Additional Judgment' as to the allegations and evidence emphasized by this court, all of which are the same as the reasoning of the judgment of the court of first instance. Thus, it is citing it as is in accordance with the main sentence of Article 420 of the Civil Procedure Act

2. Additional determination

(a) In order for a contractor to claim additional construction costs against the contractor in addition to the contract price stipulated in the relevant contract, the contractor must prove that there was an agreement between the contractor and the contractor to pay the additional construction or modification works, such as the execution of the contract to increase the contract price, and the payment of the construction cost separately, in addition to the execution of the additional construction or modification works not included in the relevant contract, unless there are special circumstances.

B. (Supreme Court Decision 2005Da63870 Decided April 27, 2006).

As to the assertion on the cost of reinforcement construction, the Plaintiff discovered the error of the basic construction work that the Defendant performed while the construction work was performed on March 17, 2018, and additionally performed the reinforcement construction work on March 17, 2018. Thus, the Plaintiff asserted that the construction cost of KRW 9,621,00 should be paid (i.e., cost of KRW 1,60,000, such as cost of equipment cost of KRW 8,021,00,000), but each description of the evidence Nos. 3, 6, 8, and 9 (including additional number) was erroneous for the Defendant’s primary construction work, thereby making the Plaintiff’s additional reinforcement construction work worth KRW 9,621,000,

It is not sufficient to acknowledge that the defendant agreed to pay the additional construction cost, and there is no other evidence to acknowledge it.

The plaintiff's above assertion is without merit.

C. As to the assertion on the increase in construction price following the change of construction materials, the Plaintiff agreed to use the pipe material in the design drawing at the time of concluding the instant construction contract with the main material 71.2 x 14.0t x 14.0t, but instead, the pipe in the bred size.