The Cross-Grain House houses Lio Gallery, an exhibition space dedicated to sculptures, furniture, and artworks in wood, together with a workshop and the artist’s residence. Set into the hillside of Heyri Art Valley, the site rises 35m between the lower and upper roads, with a further 10m climb to the north where two grains of contour intersect. While houses on steep terrain in Korea are typically built by cutting into the slope to insert parking and capping it with a lawn garden supported by high retaining walls, this project instead seeks continuity between natural and built surfaces, avoiding damage to the terrain. In landscape, contour lines cut at consistent 1m intervals yield ever-shifting curves on the plan. The Cross-Grain House reverses this logic: its structure is organized in a consistent 1m spacing on the plan, while variation is expressed in section. Through this reversal, landscape and architecture enter into dialogue, offering a method of integration between the natural and the built. Wrapped in a continuous copper skin of solid and perforated panels, the building echoes the color of the surrounding soil, yet deliberately contrasts with the wooden works displayed inside.