1. The construction cost for the Defendant in relation to the first installment contract for sewage rock construction (construction section) with the village with which the Plaintiff was placed, 34.

1. Facts of recognition;

A. On April 2, 2015, the Plaintiff entered into a construction contract (hereinafter “instant contract”) with the Defendant for construction works to newly expand sewage rocks in the area of 8,927,950,000 won (the first minute 3,856,974,000 won).

B. On December 2015, the Plaintiff completed the said primary part of the construction (hereinafter “instant construction”) and used recyclables, not new products, to be used in the process.

C. Around that time, the Defendant settled the instant construction cost and paid KRW 4,061,80,000 to the Plaintiff.

On April 2016, Seoul Special Metropolitan City notified the Defendant of the audit results to the effect that the difference between the river fee based on new products and the river fee based on the recycled products should be refunded, even though the Plaintiff calculated the construction cost and concluded the instant contract on the basis of new products with respect to the instant construction works. Accordingly, on April 2016, the Defendant demanded the Plaintiff to return the difference to the Plaintiff through the drawing engineering corporation, a construction project management company of the instant construction project (hereinafter “Dorified Engineering”).

[Ground for Recognition: Facts without dispute, Gap evidence 7, Gap evidence 9 and 10 (including paper numbers), the purport of the whole pleadings]

2. The parties' assertion and judgment

A. The plaintiff's assertion that in relation to the construction of this case, the Soil Glaps Corporation is included in the temporary installation, so it is allowed to use recycled materials, not new materials, and the plaintiff should not reduce the construction cost on the ground that he used recycled materials, which are recycled materials. Accordingly, the defendant shall not be included in the temporary installation work, but the Earth Glaps Corporation shall not be included in the temporary installation work.