Abstract: Under the territorial spatial planning system, detailed planning serves dual roles as both a statutory framework with rigid constraints and a practical policy instrument. Addressing challenges from past urban-rural planning practices-where regulatory detailed planning overly relied on dynamic adjustments to passively 'adapt' to developmental demands, leading to inadequate per capita public space regulation, compromised social equity, and insufficient protection of residents' rights-this study conducts an empirical analysis of Open Space Ratio (OSR) in newly constructed residential communities in Hebei Province. By analyzing the appropriate control range of OSR guided by public preferences, it proposes a minimum OSR standard for residential land to ensure per capita open space baselines. The framework integrates this minimum OSR with flexible plot ratio ranges, while establishing coordinated control rules linked to building density, height, and other indicators. This creates an integrated OSR governance system for residential land that combines 'baseline safeguards + adaptive calibration', thereby enhancing operational feasibility and planning adaptability.