Guesthouse Rivendell is located on the riverside in a suburb of half-hour drive from a city. The client, raised by a single mother, is a self-made entrepreneur who overcame adversities. Having bought a plot near beautiful Bukhan River, he commissioned designing a house of 1,000㎡ for his mother. Architecture on the riverside is ever-changing with the seasons due to repeatedly shrinking and expanding condition of ground, and fluctuating level, cloud and mist, freezing and thawing of river. Especially, the river breaks the boundary of land and reveals its rigid floor when it starts to freeze in winter. This can expand the range of the site on a grand scale toward nature. Thus the direction of this project is set to provide an architectural device that interacts with various changes of nature and to secure a room for nature and architecture to intervene each other. Guesthouse Rivendell is planned to lie at right angles to the river flowing from south to north, so that east-west axis of view and wind is clearly secured. The building mass is designed like tree branches stretching outward in order to provide a condition for the interplay of nature and architecture. Thus this project can be described by the courtyard within the whole mass and the outdoor space subject to natural condition. First is the boundary area. The site, facing Bukhan River to the east, experiences seasonal change and expansion in the winter time. Living room, dining room, and kitchen are placed along this side on the first floor, and a master bedroom on the second floor. A huge cantilever on the second floor provides a place to enjoy the view to the river and outdoor activities in all weather conditions. The outdoor deck with a swimming pool provides a place to hold a party and enjoy water activities. In winter, one can take a walk across the frozen river. Second is the garden in the south of the site. This area of intimate landscape and waterscape provides guests separate approach to the house. Pedestrians can appreciate Korean style garden of pine trees and various flowers through the transparent glass of the long corridor unraveling like a skein of thread. Third area is the entrance facing the mountains along the path to the west. Passing the main gate, one can approach to the entrance of the house below the dramatic 14.7m long cantilever structure. The second floor of this part is designed as a gallery in the corridor, where one can see the seasonal changes of mountains to the west. This space is connected with the multi-room in the basement and rooms on the second floor. In addition, the contrast between concrete skins with different textures contributes to the form. Last area is the courtyard. Besides of inner circulation, approach from the outside can lead to this landscape area continuing from living room to the second floor and rooftop deck. The gently sloping rooftop deck, made of narrow wood panel, looks like a new stream which joins to the river in front of the building. The courtyard includes a lawn garden on the slope, which conveys the sense of seasonal change to the living room. In fact, the light well in the courtyard evokes emotional feeling when it rains or snows. Among various architectural projects, housing design is not easy to adopt spatial feature and structure which go beyond the common idea about ordinary living space. When architectural characteristics are to be addressed for a residence design, one solution may be found by seeking them in the relationship between spaces rather than freshness. The relationship covers from the layout and two-dimensional relationship of architecture to three-dimensional feature of nature and space interpenetrating and interacting with each other. The site of Guesthouse Rivendell is a bit large for a house. Thus the layout of the building is intended to avoid the situation where the site looks like a desert due to dwarfish mass of the house. The body of the building spreads out in all directions like a branch so that it can divide the large site properly and increase the surface of the building to the maximum. Sequence plays a role as a significant concept in this building. Unlike typical duplex houses, upper and lower parts of Guesthouse Rivendell, adopting long circulation system, are separated. This can provide different views according to each route and viewpoint. Guesthouse Rivendell can be hardly regarded as a new principle of architecture or an experimental house. But the outward view from the inside of the house will give a chance to witness at every moment and in every spot the changes of nature whose familiarity is disintegrated like glass fragments. If we can find an object that doesn’t make us bored easily in the world, I think it is nature and architecture which can embrace the nature properly.