Rapid urbanization and housing shortages in Stockholm have led to the adaptive reuse of non-residential buildings for residential use. While adaptive conversions offer sustainable and cost-effective solutions to housing shortages, there is critical concerns about urban livability—particularly the equitable provision of green spaces, essential for residents' mental well-being. This thesis assesses the accessibility to green spaces in adaptive building conversion projects in Stockholm County, including case studies Kista Square Garden, Lyceum university conversion, and Nacka conversion project, and examines its impact on residents' mental well-being. A mixed-methods approach including GIS spatial analysis, resident surveys, stakeholder interviews, policy document review, and site observations was undertaken. A dual categorization framework was applied to examine types of green spaces (e.g., urban, natural, multifunctional) and accessibility (physical, legal, social, functional) for residents. Research denotes significant discrepancies in green space accessibility across various locations, an aspect influenced by urban typology, planning limitations, and policy implementation. While some projects effectively integrated green spaces, such as by implementing rooftops and courtyards, others faced challenges caused by heritage restrictions or spatial isolation. The study emphasizes the necessity of integrating equitable and inclusive green space planning in adaptive reuse projects to enhance mental well-being. The study concludes with recommendations for incorporating green spaces into housing conversions across diverse urban environments.