1. The plaintiff's appeal against the defendants and the defendant B's appeal are all dismissed.

2. The costs of appeal shall be borne respectively by each party.

1. Basic facts

A. The Plaintiff is a company running the construction business, and Defendant B is the owner of 6,986 square meters of forest E in Yangyang-si (hereinafter “instant land”). Defendant C is the largest wife of Defendant B, and Defendant D is the wife of Defendant B.

B. On September 19, 2014, the Plaintiff concluded a construction contract with Defendant B to construct housing by setting the construction cost of KRW 170 million on the right side of the second part of the instant land (excluding value-added tax and the payment method thereof, KRW 68 million in advance at the time of conclusion of the contract with respect to the method of payment thereof, KRW 68 million in advance after the completion of the steel structure, the intermediate payment of KRW 68 million in advance, and the remainder of KRW 34 million within seven days after completion, and the period of construction from September 19, 2014 to December 28, 2014).

(hereinafter “former Construction Contract”). Under the said contract, the Plaintiff commenced construction works on September 22, 2014 in the part of the instant land.

C. After commencing construction on October 29, 2014 of the instant land, the Plaintiff entered into a construction contract with Defendant B to construct housing by determining the construction period from November 10, 2014 to February 28, 2015 as follows: (a) the construction cost on the ground on the right-hand side of the said part of the instant land (excluding value-added tax; (b) KRW 40 million upon entering into a contract on the method of payment; (c) the intermediate payment of KRW 60 million after the completion of the framework construction; and (d) the remainder of KRW 50 million within seven (7) days after the completion of the construction; and (e) the construction period from November 10, 2014 to February 28, 2015.

The term "the first construction contract" is "the second construction contract", and the term "the second construction contract" and "the second construction contract of this case" are "each construction contract of this case".

D. Since then, the Plaintiff completed each of the construction works for building structures on the ground of the first and second parts of the instant land, but around January 21, 2015, the Plaintiff discontinued construction works on the ground that the Defendant delayed the payment of the construction cost under each of the instant construction contracts.

E. Meanwhile, on October 15, 2014, Defendant B paid to the Plaintiff KRW 20 million, KRW 17,000,000 on October 17, 2014, KRW 30,000,000 on October 24, 2014, and KRW 60 million on October 24, 2014, as the construction price under the proviso to the second construction contract, and the first part.