Located in Ningbo, China, the project is a small architectural studio's office. For budget considerations, the studio chose a 30㎡space as the site. With a width, depth and height of 2.88m, 8.7m and 6m, the original space was long, narrow and lofty, stretching in north-south direction. To optimize spatial utilization at vertical level, the design team created a mezzanine and a staircase. The staircase is multifunctional: the area no more than 3m high is used as steps, and the section above under a height of 4.5m functions as seats. Besides, a 3.5m-high sunken area was carved on it for planting. This large staircase serves various purposes such as working, discussions, salon and lectures. Storage space is attached to walls, which form a storage system surrounding the entire space. The system includes 2 parts: a shelf with a width of 2.8m at the top and a loop of hanging bar at the bottom. To ensure a smooth circulation, the design team converted the back window into a folding door, which can be opened and closed flexibly. Grayish silver was used as the dominate hue, which brightens the entire space. Diatom mud that produces horizontal grain and the ripple-pattern stainless steel show the collision of textures. Material and color divisions helped shape the functional layout, and also eliminated the oppressing feeling in the space. Sponge, binding belts and EPV foam with aluminum foil were used to make cushions and wrap desk legs, which reduced cost and enhanced sustainability.