How to achieve a balance between functional improvement and heritage conservation? A case study on the renewal of old Beijing city

Historic city centers require function optimization, while simultaneously being pressured to maintain their heritage conservation and utilization. How to reconcile the two is currently a challenge for the regeneration of many old cities. With old Beijing city as the study area, this study innovatively interpreted the value of heritage from the perspective of urban functions, showing the multiple roles and identities of heritage in modern adaptation. In past 40 years, the gradual improvement of urban functions and more even distribution of facilities in old Beijing city comes at the expense of 51.6% of the historic architectural district. Modern urban heritage exists as several types of functions, mainly tourism-attractive heritage as ancient capital's explicit carrier of history and culture, urban-functional heritage as a stock resource for rational use, combined tourism-attractive and urban functional heritage. Compared with other zones, historic areas have more mixed functional units, predominantly residential mixed with cultural, scientific and educational, and administrative functions. A case study was conducted on nine types of typical heritage sites and their surrounding functional organization patterns, providing references for balancing urban function optimization and heritage conservation and utilization for sustainability.