According to the report of chinalibs.net, in September of 2021, 276 giant glass curtain walls began to be installed as Beijing City Sub-center Library’s exterior. “Forest canopy”, formed by 144 “ginkgo leaves”, was completed in shape. Exterior wall and metal roof were estimated to be installed and would make its official debut at the end of year.
As one of the three main buildings of Beijing City Sub-center, the design concept of Beijing City Sub-center Library derives from Chinese traditional cultural symbol, Red Yin”(which means red ink paste used for seals). The total construction area of the library will be 30,000 square meters. The red color of this building originates from the metal roof of the library. Inside the library, there  will be two rolling mountain-shaped structures, full of change but an integral whole, unifying the exterior and interior spaces, forming a mutual infiltrated space relationship. The whole project is scheduled to be completed in December of 2022.