Nature-based Solutions (NbS), such as constructed wetlands, raingardens and reforestation, have emerged as a promising opportunity for improving living conditions in quickly growing cities. Experiences in practice, however, indicate that the decision-making processes that underpin housing projects, particularly in informal settlements upgrading programs, are still not conducive to the mainstreaming of NbS. We explore the case study of the Baan Mankong (BMK) housing program in Thailand to examine the barriers, benefits, and responsibilities of different stakeholders when implementing NbS. In doing so, we conducted (A) an online survey with stakeholders and (B) a series of semi-structured interviews with the residents of housing projects in Bangkok. The comparison of the results from both methods shows that the perceptions of the surveyed stakeholders often differ from the residents' experiences with nature. While the surveyed stakeholders have a reasonable understanding of the barriers that prevent NbS from being implemented in Bangkok, the findings point to important gaps regarding costs, expectations and shared responsibilities that should be addressed to ensure that NbS can be effectively mainstreamed within housing projects. We build upon the findings to examine why NbS are not fully incorporated into housing programs in Thailand and more broadly.