Abstract
Societal challenges highlight the need for a green urban transformation, where Nature-based Solutions (NBS) play a crucial role. Despite their potential, the integration of NBS into spatial planning remains a significant challenge. This study examines the factors influencing NBS adoption in spatial planning in the Stockholm region, Sweden. Using a two-step mixed methodology, the research combines quantitative analysis of NBS-relevant terms in municipal comprehensive plans (CPs) from 26 municipalities and two regional plans, followed by focus group discussions with planning officials from five municipalities. The findings reveal significant variation in the integration of NBS in the CPs and their practical application, with notable barriers related to political, socioeconomic, and local contexts. Key challenges for planning interventions involving extended NBS include inadequate legislation, limited resources, lack of political will, and insufficient inter-institutional collaboration. In conclusion, despite strong advocacy for NBS integration, the lack of systematic and structural support hinders a transformative shift in Swedish planning towards a broader NBS framework.