<p>Although the “15-min city” concept has gained currency in urban planning, limited attention has been paid to the comprehensive effects of multiple accessible amenities on urban outcomes. This study tried to provide insight into outcomes of the 15-min city by examining the combinational effects of living service amenities on housing prices in Shanghai, China. An enhanced two-step floating catchment area (E2SFCA) method was employed to measure the supply–demand relationship between urban amenities and residences, and a gradient boosting regression tree (GBRT) was applied to identify the combinational effects of urban amenities on housing prices. E2SFCA showed polycentric patterns in the supply–demand relationship between population and amenities, distinguished from traditional measures like distance and density. According to the LightGBM model, we find that accessibility of commerce amenities shows strong positive correlation with housing price, while accessibility of other amenities show nonlinear association with housing price. Further analysis identify the combinational effects of amenities on housing price. Three types of combinational effects have been identified, including positive interaction, incompatible interaction and conditional interaction. For example, there is positive interaction between sports and education amenity that contributed to higher housing prices; culture and education amenities were incompatible to reduce housing prices; The combinational effects between healthcare amenities and commerce amenities on housing prices were only found when accessibility of commerce amenities is low. These findings are helpful in understanding the nexus relationship between urban amenities and housing prices under the concept of the 15-min city.</p>