Cultural institutions based on historical formal social structures have stopped working well. I propose non hierarchy architecture as civic institution. It is an open architecture that the servant space and the served space are switched and the functions are changed from time to time. This building functions as a library in everyday life and as a concert hall in Extraordinary. The building has a open ceiling space in the center with a gentle slope surrounding it. The slope allows you to go up and down without division, creating a continuous space and bringing the experience of connecting the city to the ground.