A. On May 9, 2018, the Plaintiff entered into a subcontract with C (hereinafter “C”) with respect to the roof construction among the E-works ordered by D Co., Ltd. (hereinafter “instant construction”) by setting the contract amount of KRW 1.2 billion and the construction period from May 9, 2018 to January 27, 2019, with respect to the E-works ordered by D (hereinafter “instant construction”).

(hereinafter “instant subcontract”). After that, on June 14, 2018, the Plaintiff entered into a sub-subcontract with the Defendant, setting the contract amount of KRW 522,500,000 (including value-added tax) with respect to some of the instant construction works (including labor parts) and the contract period from May 9, 2018 to October 31, 2019.

(hereinafter “instant sub-subcontract”). (b)

The main contents of the sub-subcontract of this case are as follows:

Special Provisions Concerning Contracts

1.General Matters 2) At the time of work, construction must be conducted after obtaining approval from the responsible engineer after consultation with the responsible engineer, and construction must be reconstruction at the defendant's expense when the problem arises. 11) All operations shall correspond to specifications, drawings, and specifications.

(Provided, That in the event of the occurrence of a problem through voluntary execution, all the responsibilities to the defendant shall be borne by the supervision or supervision, or consultation with the contractor.

2. He shall complete all the works within the prescribed air space(s)(s). (All the expenses for care work and additional personnel input shall run under the responsibility of the defendant.

3) The settlement shall be made for an increase or decrease in quantity at the time of completion of the construction and must meet the following conditions at the time of settlement:

(A) The amount adjustment for price fluctuations within the contract period shall not be made in accordance with the changes in the drawings (b) the changes in the drawings and the changes in specifications (applicable only to the portion recognized as water consumption at the original office).

C) If the volume of actual goods is reduced but the quantity is not reduced at the original office, the original and the Defendant shall consult and make payment after determining the quantity. [The increase or decrease in quantity (within 5 per cent) shall not be settled.