The defendants are jointly and severally liable to the plaintiff 16,814,00 won and 6% per annum from March 14, 2020 to July 23, 2020.

1. The Plaintiff, at the end of February 2017, did not dispute the fact that the Plaintiff was awarded a contract with the Defendants for construction cost of KRW 570,000 per the average construction cost, and completed the construction by June 22, 2017, from among the two new construction works of Guro-gu Seoul Metropolitan Government D Multi-household Housing (hereinafter “instant construction works”) by the Defendants, does not conflict between the parties.

2. The parties' assertion

A. Since the Plaintiff’s instant construction work is executed on approximately 500 square meters, the entire construction cost is KRW 285 million (=570,000 + 500 square meters).

However, the defendants pay only KRW 249,200,000 among the construction cost, and do not pay the remainder of KRW 35,80,000,000.

B. Although the Defendants estimated 419 square meters, the Defendants calculated 450 square meters as follows, the entire construction cost is KRW 255,650,000 (=570,000 + 450 square meters).

However, since the Defendants already paid KRW 268,186,00 as the construction cost, there is no additional payment for the construction cost.

3. First of all, with respect to the construction cost of the instant construction project, a contract for construction works has not been prepared between the parties, but in this case where there is no dispute, the construction cost should be calculated according to the construction area.

According to Gap evidence Nos. 3 and Eul evidence Nos. 1 and 2, the construction area of the instant construction project is approximately 497 square meters (1,642.84 square meters) in total on the register among the construction works in which two multi-household houses are constructed, and approximately 513 square meters (1,696.64 square meters) on the register is recognized. As such, as alleged by the plaintiff, it is reasonable to calculate the total construction amount as KRW 285 million (570,000 square meters x 500 square meters) on the basis of 500 square meters in the construction area as alleged by the plaintiff.

As to this, the defendants argued that the underground floor was reflected only 50% of the area, and the total area was only 419 square meters, but the defendants were 450 square meters in each subparagraph, but the underground floor was reflected only 50% of the area of the underground floor.

or the total area of the construction works.