In the biological world, there are species that are perceived as undesirable in a particular area. The purpose of this project is to redefine the biological infrastructure of those undesired plants. Three spaces are created from new undesired plant materials which have been given back to human ecosystems, ground cover plants, mycelium, and birds. This is done not only through the existence of these spaces but also through their disappearance. This project creates a "living architecture" while indicating the slow death of architecture which is believed to be semi-permanent. 01 -The Tent made of new paper from Nettle and lime for controlling acidification of forest soils- In Switzerland, methods of spraying lime on forest soil are being tested to control forest acidification. This tent is a temporary roof which allows lime to be spread. The pavilion are decomposed by rain and micro-organisms and will be slowly absorbed over time into part of the forest's biological cycle. 02 -The cabin made of new panel from Tree of heaven for culturing mushrooms- Creating a small wall that utilizes the properties of the Tree of heaven, a wood that is suitable for the cultivation of mushrooms. It is a primitive pavilion, using just a stack of mushroom culture panels and logs which form the base for growing the mushrooms. As the month's pass, the new panels supporting this wall become unstable due to moisture, and finally the pavilion slowly disappears, returning to the original natural cycle. 03 -The Tower made of new pillar by bundling Japanese knotweed for birds- There are few tall trees for birds in cultivated land in Switzerland, therefore, every winter, pillars can be made, taking advantage of the characteristic of Japanese knotweed to grow and become hard. The plant will be reconstituted to become a temporary tower for birds. As the joints of this tower are not completely fixed, but the materials are structured to support each other, over time this pavilion gently disappears.