A. On January 31, 2013, the Defendant entered into a contract for construction work between the Defendant and the school foundation’s accommodation (hereinafter “the instant construction”) with respect to the construction work of urban-type residential housing (hereinafter “the instant construction work”), which was implemented by the school foundation’s accommodation in Gangnam-gu Seoul, Gangnam-gu, Seoul, for the construction cost of KRW 11,60,000,000 and the construction period from February 1, 2013 to August 31, 2013, by setting the construction cost as between February 1, 2013 and August 31, 2013.

B. On March 21, 2013, the Plaintiff entered into a subcontract contract between the Plaintiff and the Defendant with respect to the subcontracted construction work (hereinafter “instant subcontracted construction work”).

As to the construction cost of KRW 805,600,00 (including value-added tax) and the period of construction from March 21, 2013 to July 10, 2013, the subcontracting contract was concluded. 2) The Defendant completed the subcontracted construction in this case under the said construction contract.

C. 1) Execution of an additional construction of a reinforced floor (hereinafter referred to as “afluent apartment management”) of the volatile apartment management company (hereinafter referred to as the “fluent apartment management”), which is the company PM management of the instant subcontracted construction, at the end of the period of the instant subcontracted construction.

2) The Defendant’s additional construction of the reinforcement floor (hereinafter referred to as “instant additional construction”) that is a kind of finishing construction (hereinafter referred to as the “instant additional construction”).

(2) On July 8, 2013, the Defendant requested the Plaintiff to perform the instant supplementary construction separately from the instant subcontracted construction. (2) At the time of the Defendant Company’s request, the Plaintiff issued a tax invoice on the costs of materials of the reinforced floor following the instant supplementary construction. Accordingly, the Plaintiff issued an electronic tax invoice to the Defendant regarding the costs of materials of 85,654,80 won (including value-added tax) of the strengthened floor.

3. On July 12, 2013, the Plaintiff received material costs of 85,654,800 won from the Defendant for the above reinforcement floor, and the instant additional construction costs incurred in material and construction in addition to the above material costs. The instant additional construction costs are 260,000.