1. According to the Plaintiff’s amendment of the purport of the claim in the trial, the judgment of the first instance is modified as follows.

The defendant.

1. The following facts do not conflict between the parties, or can be acknowledged in full view of the entries in Gap evidence 1, Eul evidence 1, Eul evidence 1, 4, and 5 (including the whole number; hereinafter the same shall apply) and the whole purport of the pleadings:

The Plaintiff is engaged in general construction business with the trade name of “C”.

B. On May 25, 2013, the Defendant requested an architect E to design the construction cost of KRW 5,000,000 per square meter with respect to the new construction work of the Gangwon-do Crossing-gun D ground electric source housing (hereinafter “instant housing”).

E introduced the Plaintiff to the Defendant around that time as the contractor who will proceed with the instant construction work in KRW 5,00,000 per construction cost per square.

C. On June 11, 2013, the Plaintiff entered into a contract with the Defendant for construction works (hereinafter “instant contract”) with the terms that the Plaintiff would receive KRW 5,000,000 (excluding value-added tax; hereinafter the same shall apply) for the construction cost of the instant construction works from the Defendant, and the construction period from June 1, 2013 to December 30 of the said year.

However, at the time of the instant contract, the Plaintiff and the Defendant agreed to temporarily set the total construction cost as KRW 250,000,000 on an estimate of the 50 square meters at the time of the instant contract, and to pay the increased construction cost as KRW 5,00,000 per square year when the building area increases.

The instant house obtained approval for use after completion of construction work on July 10, 2014. Each area on the registry of the instant building and on the registry of the general building is 112.3 square meters, 2 stories 84.21 square meters, 47.31 square meters in total, 243.82 square meters in total (76 square meters in 73.76 square meters in = 243.82 square meters in total, 3.3057 square meters in number, and small numbers).

E. The Defendant paid to the Plaintiff KRW 315,00,000 as the instant construction cost, and KRW 28,500,000 as the Plaintiff’s site manager, and KRW 343,50,000 as the Plaintiff’s site manager.

2. Determination on the cause of the claim

(a) Building area and construction cost;