T This study explores the architectural adaptation of the heritage building pos bloc jakarta in response to social and economic dynamics in an urban environment. using a qualitative approach through robert k. yin’s case study method, the research focuses on examining the transformation of the building’s physical aspects namely function, form, and structure within the framework of adaptive reuse and historical preservation. originally serving as a colonial-era central post office, the building underwent revitalization in 2021, shifting its function into a creative economy hub encompassing culinary businesses, retail outlets, art galleries, and community spaces. while the building’s facade and massing remain largely preserved to maintain historical authenticity, interior spaces were reorganized to support new functional requirements. structural elements such as columns and roofing systems were strengthened and adapted to accommodate contemporary lighting and circulation needs. primary data were collected through field observation, interviews with stakeholders, and document analysis. the findings highlight that the adaptive transformation supports economic revitalization by enhancing commercial viability and attracting visitors. socially, the space functions as an inclusive public area that fosters interaction and cultural engagement. the architectural interventions illustrate how heritage buildings can be revitalized through thoughtful adaptations that respect their original character while embracing modern socio-economic functions. the research concludes that adaptive architectural strategies offer a sustainable approach for repurposing heritage structures in indonesian cities. it contributes to the discourse on preserving historical identity while responding to evolving urban needs.