A. On September 18, 2012, the Plaintiff entered into a construction contract (hereinafter “instant construction contract”) with the Defendant, Yangsan-si, with respect to the construction work of multi-household detached houses and neighborhood living facilities (hereinafter “instant construction work”) on the fourth floor above the ground (hereinafter “instant construction work”), setting the construction cost of KRW 372 million as the construction cost, September 18, 2012, and February 28, 2013 as the completion of construction.

In the contract and other matters column, it is written that “(i) TV, cooling, air conditioners, washing machines (hereinafter “instant equipment”) included, and ② no additional amount exists.”

B. After the commencement of the instant construction, the Plaintiff completed most of the construction except for the installation of the instant fixtures, and obtained approval for the use of the new building on May 6, 2013, and the Defendant completed registration of the preservation of ownership on May 22, 2013.

C. On the other hand, around May 2013, prior to the registration of initial ownership preservation, a modified contract was drafted that increases the construction amount to KRW 422,80,000 on the ground of the increase in the construction cost due to the change in quantity in the instant construction contract under the name of the Plaintiff and the Defendant (hereinafter “instant modified contract”).

By March 27, 2013, the Defendant paid KRW 37 million out of the construction price of the instant case to the Plaintiff, and on October 21, 2014, after the instant lawsuit was filed, the Plaintiff was deposited as the principal deposit in Busan District Court Decision 7648 on October 21, 2014, and paid KRW 526,001 as the balance of the instant construction project.

[Ground of recognition] Facts without dispute, Gap evidence 1 to 4, Eul evidence 12-14, the purport of whole pleadings

2. Assertion and determination

A. The Plaintiff asserted 1) The construction cost of this case is KRW 422,80,000 under the modified contract of this case, while the new building of this case is subject to exemption from additional tax or exemption from construction permission with retail stores in the case of the first floor, so the Defendant is obligated to pay additional tax of KRW 6,532,260 for the part of the construction cost, on the premise that the Defendant is obligated to pay additional tax of KRW 6,322,60 for the said part of the construction cost.