Social impact assessment and environmental impact assessment have developed as separate entities, but a full appreciation of all impacts requires a thorough understanding of all the biophysical and social changes invoked by a planned intervention. Biophysical impacts also have social impacts, and social changes can cause changes in the biophysical environment, which create biophysical impacts. To date, there has not been an adequate framework for integrating biophysical and social impact assessment. This paper presents a method for such integration using function evaluation as a conceptual framework. This has led to a better understanding of the full extent of human impacts, and the impact pathways that lead from interventions to the experience of impacts.