The transitional space was designed around a twisted nonlinear hexahedron staircase, which connects the functional spaces. The stair resolves the vertical transportation issue fromthe tea house and the library and provides an inner courtyard near the reading room for viewing the existing tree. The space was designed to bring a new experience to an ordinary functional space. Linear space suddenly changes into an expressive form, surging from the tea house then transforming into a tranquilspace for the library on the floor above, making the reading room a special place to sit.