1. The Defendant’s KRW 52,200,657 as well as 6% per annum from January 10, 2013 to December 3, 2014 to the Plaintiff.

1. Basic facts

A. The Plaintiff is a construction business operator, and the Defendant is the owner of the instant house with the ground-based C in Yongsan-gu, Busan Metropolitan City (hereinafter “instant house”).

B. On August 31, 2012, the Plaintiff negotiated with the Defendant regarding the conclusion of the contract for remodeling construction of the instant housing (hereinafter “instant construction”). The Plaintiff prepared a quotation and design drawings (hereinafter “instant design drawings”) and presented them to the Defendant. The Defendant additionally excavated a part of the unit of the instant housing into the depth of the first floor of the instant housing so that the Plaintiff may enter the underground space of the instant housing and the installation of retaining walls and stairs, etc. (hereinafter “the space formed as a result of installing retaining walls and stairs,” and the said construction was called “the installation of outer underground space”).

C. On September 9, 2012, the Plaintiff commenced the instant construction work.

On October 2, 2012, the Plaintiff, upon the Defendant’s request, presented a cost statement (Evidence A 4; hereinafter “instant estimate”) that causes the total construction cost to 239,246,855, by reflecting installation works for air conditioners and walls and installation works for external underground spaces. The Plaintiff and the Defendant, the same day contract amount to 220,000,000 won (excluding value-added tax) and the construction period from September 9, 2012 to November 5, 2012, prepared a construction contract (hereinafter “instant contract”) under which the instant construction works are contracted (hereinafter “instant contract”).

"9. Other matters" in the contract of this case includes "1........." and "the second contract for the adjustment of the additional amount of construction works (referring to the installation of external space for civil and civil works)", and Article 2.1 of the terms of the contract attached to the contract of this case shall be "the buildings specified in the design documents".