This is a hospital addition project in a dense old town, so the urban planning has stringent requirements for the spacing and retreat of the building. We enclose the new buildings with the old ones so as to form a central courtyard. A vertical green public space with rich layers is created in a cramped land with the help of volumetric segmentation and combination, which consists of a welcoming garden on the roof and a green platform in the air. The building is mainly facing the west, so the ward has direct sunlight in the afternoon and the thermal environment and the light environment are not conducive to the patient. In view of that, the design forms a rhythmic facade by combining the horizontal and vertical sun-shading components, which effectively prevents dazzling light and reduces energy consumption.