The problem of cumulative impact (CI) is an under-researched issue in spatial planning theory and practice with important implications for sustainability. This paper investigates how cumulative impact is addressed within the Scottish planning system through a case study focused on small-scale wind developments in Aberdeenshire UK. Using assessments of planning applications and stakeholder interviews, the findings revealed a disjuncture between considering applications on their own merit versus more strategic and long term considerations. The lack of sufficient guidance tailored to the specific scale of development poses significant proportionality problems. We argue for a more positive dialogue between planners, developers and supporting agencies championing adaptive management and social learning frameworks in order to improve CI processes and outcomes.