The judgment below is reversed and the case is remanded to Seoul High Court.

The grounds of appeal are examined.

1. According to the reasoning of the first instance judgment cited by the lower court, the lower court acknowledged the facts as indicated in its reasoning and found the following facts, i.e., the Defendant was not aware that the instant elevator was installed with a fixed camera, not in the size stipulated in the instant contract, but in the instant elevator. Furthermore, there is room to deem that the Defendant impliedly consented or consented to the Plaintiff to install a fixed camera in the said elevator; and ii) there was intention from the beginning to install CCTV using a fixed camera in the instant elevator, different from the shop design.

In addition to the plaintiff, the plaintiff seems to have installed the above elevator without properly confirming the size of CCTV camera supplied by the plaintiff. ③ The plaintiff, followed the plaintiff, and then asked the defendant's construction supervisor of the new letter loan, a corporation that entered into a contract for the improvement, supplementation, and new elevator manufacture and installation of the elevator. The defendant's construction supervisor asked the defendant's construction supervisor of the elevator to build the CCTV model installed in the elevator. ④ The price difference between fixed type camera and variable type camera is about 46,640 won per unit, and the plaintiff is found to have used the fixed type camera, which is lower than that stipulated in the specifications, and the whole CCTV of this case was replaced with the variable type, and the defendant's construction supervisor of the elevator was found to have applied the CCTV model to the defendant's construction supervisor of the elevator, and the defendant asked the defendant's construction supervisor of the elevator to set the CCTV model installed in the elevator, and the plaintiff's construction supervisor of the elevator at the same time as the CCTV type installed prior to the new letter loan.