A. The Plaintiff, upon consultation with the Defendant on the large-scale repair works of neighborhood living facilities and housing units on the third floor above the third floor above the ground below the Dongdaemun-gu Seoul ground (hereinafter “instant building”), presented a written estimate (Evidence A2; hereinafter “written estimate on July 3, 2015”) as of July 3, 2015. (B) Based on this, the Plaintiff, as of the instant construction work, included installation works on the large-scale repair of the instant building (including installation works on the outer and second floor under the written estimate as of July 3, 2015, which include installation works on stairs that are lowered into the second floor toilets and the second floor; hereinafter “instant construction work”). The Plaintiff entered into a construction contract on a written estimate (Evidence A3) with the Plaintiff to additionally consult with the Defendant on the construction work under the written estimate as to KRW 137,300,000 (value-added tax).

In addition, according to the Defendant’s request to the Plaintiff for the addition of various construction works other than the written estimate on September 2, 2015 (the “instant additional construction works” up to September 2, 2015), the Defendant performed the instant additional construction works.

[Ground of recognition] Facts without dispute, entry of Gap evidence 1 to 4, purport of the whole pleadings

2. The parties' assertion

A. The Defendant: (i) the sum of KRW 24,915,000 for the instant additional construction cost (i.e., KRW 9,801,00 for the additional construction cost stated in the written estimate as of September 2, 2015; KRW 15,114,00 for the additional construction cost stated in the written estimate as of September 2, 2015); and KRW 2,028,00 for the payment of public charges (i.e., the cost for the installation of new measuring instruments: KRW 484,750 for the construction design cost of KRW 195,750 for the construction design service cost of KRW 300,00 for the construction cost of KRW 195,750 for the industrial accident compensation insurance and industrial accident compensation insurance cost of KRW 1,172,000 for the instant additional construction; and (ii) the remainder of KRW 15,710,700 for the additional construction and its amount.