A. The Plaintiff and the Defendant’s construction contract concluded each of the following contracts with the Defendant for machinery and equipment construction.

1) The construction period of the Mechanical Equipment Construction Work (hereinafter “A”) among the new construction works of A detached houses: the contract amount from June 15, 2015 to March 31, 2016: 173,250,000 won (including value-added tax) 2) the construction period of the Mechanical Equipment Construction Work (hereinafter “B”) among the new construction works of B multi-household houses: the contract amount from December 28, 2015 to April 30, 2016: 93,50,000 won (including value-added tax) the construction period from April 20, 2016 to March 17, 2017: the construction period of the Mechanical Equipment Construction Work (hereinafter “C Construction”) among the new construction works of C detached houses: the contract amount from April 20, 2016 to March 17, 200 won (including value-added tax).

B. On September 12, 2016, the Defendant ordered the Plaintiff to “Pipe, drained,” which is KRW 11,00,000 for construction cost (including value-added tax), to “a pipe work,” to “a pipe work, a pipe work outside wall of the balcony (bal roof), an outdoor civil engineering pipeline and an outstanding pipeline work,” and ordered the Plaintiff to “a toilet, drained,” which is the construction cost of KRW 1,100,000 for construction cost (including value-added tax) around November 2016.

C. The Plaintiff completed all of the construction works described in the above A and B (hereinafter collectively referred to as “instant construction”).

The Defendant paid KRW 400,300,000 to the Plaintiff out of the construction cost of the instant case.

[Ground of recognition] Facts without dispute, entry of Gap evidence 2 and 4 (including each number), the purport of the whole pleadings

2. Determination on the main claim

A. According to the above facts, the Defendant is obligated to pay the Plaintiff the unpaid construction price of KRW 25,950,00 (= KRW 173,250,500,000, KRW 93,500,000, KRW 147,400,000 - KRW 11,100,000,000 - KRW 400,300,000) and damages for delay.

B. The Plaintiff asserts to the effect that in addition to the instant construction cost, the Defendant is obligated to pay KRW 21,340,000 to the Plaintiff as additional construction cost. However, each of the entries in the Evidence No. 3 (including the serial number) is insufficient to recognize it.