This study introduces the "Hierarchical Adaptive Renewal" framework to resolve conflicts between heritage preservation and urban innovation in saturated cities, integrating three principles: hierarchization (vertical superposition of new functional layers on existing urban structures), adaptability (dynamic problem-strategy matching for current and future needs), and renewal (technological and spatial-functional upgrades). Validated in Rome’s northwestern urban-rural interface (Q. I Flaminio, Q. II Parioli), the approach combines field surveys, data analysis, and experimental interventions to address cultural-sports facility challenges. Key findings highlight micro-level flaws in macro-planning, such as redundant functions, lack of child-friendly spaces, and fragmented connectivity. Solutions include graded interventions: minimal for historic buildings, semi-intervention for high-use structures, and full redesign of generic spaces, exemplified by vertical sports complex expansions, dedicated pedestrian networks, and undeveloped land as transitional hubs. Results show improved spatial vitality, traffic safety, and community integration. The framework’s scalability extends to industrial upgrades and population mobility through vertical mixed-use complexes and smart infrastructure, positioning cities as dynamic organisms balancing cultural continuity with technological advancement. Rome’s case emphasizes multi-stakeholder collaboration and data-driven strategies, offering a sustainable model for high-density urban resilience.