This project is a renovation of a 39-year-old house with two stories above ground level and two floors below. The design concept needed to make the most of the surrounding environment with elements that connect the interior to the exterior, particularly to the quiet road, the sprawling landscape, and the beauty of nearby Namsan Mountain. The second floor was constructed as a residential space. The high floor height maximizes the vertical opening to create more spaciousness. The office space layout is conceptual, based on mathematical symbols such as '+, -, ×, ÷' and their relationship to each other.