This study examines a grassroots intervention at a primary school in Acharnes, Greece, where community stakeholders collaboratively reimagine the schoolyard as a shared green space. Through interviews, group discussions, and children's drawings, the research explores how participatory environmental practices address urban ecological challenges and social sustainability. The study investigates community-driven green space development's potential to enhance environmental consciousness, promote spatial justice, strengthen social networks, and reconnect urban communities with ecological systems. Preliminary findings highlight school gardens as critical urban ecological interventions supporting both environmental regeneration and social cohesion.