This square building is placed at a 45-degree angle to the property line to ensure a good view to the south. To make the second floor living room fully open to the landscape on the north and south sides and to private proper ventilation, two wooden walls are set parallel to each other on the east and west sides. In order to make these two walls stand by themselves and resist the lateral stresses without the need for bracing or supporting walls they, along with the steel folded plate roof structure, are tensioned by steel rods anchored to the ground outside. In this project, the folded plate roof is given a tensile function. The interior's structural plywood is used as a finishing material as well as bracing, providing that a single material can bear two functions at once to help promote low-cost construction.