Of the judgment below's counterclaim claim, the part concerning the claim for damages due to non-issuance of tax invoice is reversed.

The grounds of appeal are examined.

1. As to the ground of appeal by the Plaintiff (Counterclaim Defendant; hereinafter “Plaintiff”)

A. As long as the assertion regarding “the second modification contract” as stated in the judgment of the court below among the main claim (ground of appeal No. 1) is deemed to be authentic, the court shall recognize the existence and content of declaration of intent in accordance with the language stated in the disposition document, unless there is any clear and acceptable counter-proof to deny the contents of the statement.

(See Supreme Court Decision 2002Da23482 Decided June 28, 2002, etc.). The lower court rejected the Plaintiff’s assertion that the construction contract regarding “the second modified contract” as set out in the holding that the Plaintiff and the Defendant (Counterclaim Plaintiff; hereinafter referred to as the “Defendant”) completed and sealed by the Plaintiff and the Defendant (Counterclaim Plaintiff; hereinafter referred to as the “Defendant”) can be acknowledged as having the existence and content of the expression of intent in accordance with the language

The judgment below

Examining the reasoning in light of the aforementioned legal principles and the record, the lower court did not err by failing to exhaust all necessary deliberations or by misapprehending the legal doctrine regarding the probative value of a disposal document, as otherwise alleged in the grounds of appeal, and did not err by misapprehending the legal doctrine regarding its validity

B. The appraiser’s appraisal result regarding the cost rate among the main claim (ground of appeal No. 2) shall be respected unless there exist significant errors, such as the appraisal method, etc. is contrary to the empirical rule or unreasonable.

(2) As to the calculation of the instant additional construction cost on the ground that the pertinent contract and each modified contract are jointly applied to the calculation of the instant additional construction cost, and that the appraisal result by an appraiser pursuant to such calculation method cannot be deemed to have been excessively disadvantageous or equitable to the Plaintiff, the pertinent additional construction cost is calculated at the request of the Defendants.