This is the renovation of the multi-tenant building located in a suburb. Though there is no buildings of parking of opposite side of south side, it was necessary to keep privacy for new architecture. Because new housing is planned to build in this parking area in the near future. After part of the cement was peeling that has been removed, the surface has been carefully repaired. In addition,on the front of the building, the proposal of the facade by the vertical louvers, to act as an opposite horizontally crossing the sky went. This is not only to keep privacy is also a solution for not exposing the uneven surface and new pipes of the outer wall surface. For the rational study, innumerable patterns of facade had simulated by the algorithm which is given the condition of aperture ratio, louver size, cost, weight and etc. I tried to lead optimum solution naturally by generating the countless patterns and piling up consideration by parametric design. Last judgement didn't depend on anyone, and was adopted most rational and efficient one from the inside of several patterns. Each louvers has almost 2.55m long with the aspect of the 30mm thickness x 75mm depth. Vertical louvers beyond 300 are installed with directionality of the height and width with rhythmical bumps. The minimal interior and the neutral design intends to grant the widest range of possibilities, and tried to accomodate the maximum diversity of modern lifestyle and social needs as possible. Louvers seen from the inside space are enabling moderate viewing and lighting. New facade by louvers shows various expressions. By day, its linear shadow changes dramatically along with sunlight. By night, it's illuminated by an upper indirect lighting, and standing dimly in the twilight. The previous building buried in the miscellaneous environment revived with silence.