Urban renewal positively impacts the development of cities, enhancing building quality in deprived urban areas. However, relatively little research has been conducted on the relationship between urban renewal and social interaction in public open space. Does urban renewal have a positive impact on face-to-face social interaction? This study aims to answer this question, using the revelatory case of Sham Shui Po, a neighbourhood in Hong Kong undergoing fast urban renewal. We identified 5,372 individuals engaging in social interaction on a total number of 9,343 observations. We employed behaviour mapping and statistical analysis to investigate the association between building age and social interactions. The results show a strong linear correlation between the two variables demonstrating that in Sham Shui Po, urban renewal is detrimental to life between buildings.