A. On March 9, 2009, the Plaintiff and the Defendant for the 14 rooftop waterproof works (hereinafter “instant waterproof works”) with respect to the Defendant for the 390,52 million construction cost (including value-added tax) and the construction period from March 12, 2009 to March 12, 2009.

6. A contract for construction work was concluded until June 15, 2009, and the Defendant completed the instant waterproof construction work around the end of June 2009.

B. The specifications concerning the waterproof construction of this case state that the design of this case was constructed with an average of not less than 1.3m to 1.5m-meter with a thickness of not less than average of not less than 1.3m-1.5m in horizontal plane, and used the advantages of two materials in the upper map by constructing 0.8m to 1,00m-1,00m of polyconium on the upper map, waterproof damages caused by rupture, and light, which are characteristics of polyconium, are the same in the same manner as the method of waterproofproof method, the vertical aspect maximizes the effect of waterproof, and the vertical aspect is the same as the vertical aspect. With regard to defect repair, Article 9 of the construction contract states that the defendant is to repair without compensation for defects caused by the error in construction within 10 years from the completion date of the construction work, and the defect guarantee bond of construction specifications 10 is 5/100 of the construction cost under Article 72 of the Framework Act on the Construction Industry, and the period of construction completion shall be 5 years from the completion date.

C. However, there were only ruptures, water quality, and water leakage phenomenon in part of the rupture apartment, and in the Dongjak-gu Seoul Metropolitan Government, the apartment management status of the rupture apartment was examined around June 2013, and there was no ground to assign additional points to the Defendant’s waterproof patent construction method (other than simple 3m non-waterproof luptures and polybes together) in relation to the bid for the waterproof construction of this case, the construction cost was increased according to the patent construction method, and some parts of the results of confirmation on the site of the 102 rupture and 104 rupture-type rooftop waterproof construction site were constructed less than the size (1.5m from the rupture and 1m from the 102 rupture and 1m from the 104 rupture.