To address low fertility and enhance urban inclusiveness and sustainability, this study conducted a questionnaire survey in 35 cities in China, systematically collected data on housing inclusiveness and fertility intentions, and used the SEM to analyze the causal relationship between housing costs burden, fertility intentions, and perceived need for social housing. The results show that the housing cost burden has a statistically significant positive (+) effect on the perceived need for social housing and a statistically significant negative (−) effect on fertility intentions, and that fertility intentions have a positive (+) effect on the perceived need for social housing. Notably, the direct effect of the housing cost burden on the perceived need for social housing (0.15) is greater than the total effect of the housing cost burden on the perceived need for social housing mediated by fertility intentions (0.14). This suggests that even when housing costs are high, families who still plan to have children exhibit a greater demand for social housing. Therefore, social housing can positively impact fertility intentions and help reduce housing cost pressures on families. Additionally, actively promoting inclusive housing development will have a significant impact on the sustainable growth of the urban population and economy, making meaningful contributions.