Assessment and regulation path of physical-environmental livability quality in old urban areas under the background of stock renewal

Under the stock renewal paradigm, improving the physical-environmental livability quality (PELQ) of old urban areas is critical for sustainable urban development. This study established a multi-criteria evaluation system comprising 13 indicators across four dimensions: environment, infrastructure, safety, and green space. Using field survey data from 30 old communities in Changzhou, a typical Chinese second-tier city in the Yangtze River Delta (mean building age > 25 years), combined with remote sensing and statistical data, we assessed PELQ via entropy-weighted TOPSIS. Results show that 63.3% of sampled communities had moderate or low PELQ relative to the sample distribution, with all communities showing absolute deficits in green space compared to national standards. Correlation analysis showed that building density ( r = − 0.68, p < 0.01), population density ( r = − 0.55, p < 0.01), and green space per capita ( r = 0.71, p < 0.01) are strongly associated with PELQ. These relationships are cross-sectional and do not establish causality. Four regulation paths were identified: green space retrofitting, sponge city renovation, traffic calming, and community facility sharing. The framework requires only 13 readily available indicators and basic computational tools, making it replicable for cities with limited data. This study provides a practical assessment and decision-support tool for old urban area renewal under stock renewal constraints.