Complementary building is one of the key objectives in current urban planning as cities attempt to mitigate climate change. However, this development often reduces the urban green space. This incremental encroachment can negatively affect both the well-being of residents and biodiversity. Compensation is a way to safeguard the urban green space under the pressure of complementary construction. In the spirit of creative democracy, in this study, we examined the preconditions for ecosocial compensation and the mitigation of the harmful effects of incremental encroachment, as well as the mitigation hierarchy, in the context of land-use planning. We organised three workshops for planners and civil society associations at which we examined the preconditions for ecosocial compensation and other mitigation options using co-creation methods. We also carried out a PPGIS survey for the residents of Turku and were able to insert one question into the voting advice application of the municipal election in 2021. Our results show that there is a need for a new kind of information regarding nature-based social values when considering mitigation options and compensation. A comprehensive planning approach instead of incremental planning practices is important for considering compensation. Residents’ initiative is essential in the ecosocial approach, and the compensation process may become a way for residents to step up and introduce concerns and new opportunities to the public discussion and actual decisions about urban green space.