A principal focus of the IUPEA publications and symposiums is on reducing and mitigating environmental spillovers in urban areas, including noise, air and water pollution, risk from fire and explosion, and remediation of polluted sites. These effects often constrain desired urban development, giving rise to conflicts between spatial/physical or land use planning on the one hand, and environmental policy on the other. Examples include residential use of otherwise desirable locations being precluded because of pollution from neighboring activities. These kinds of conflicts are found in both affluent and developing countries, and lessons from each can inform the other.

An extension of this set of concerns is the sharing of information about initiatives for sustainable urban development. This includes controlling sprawl, full-cost accounting for the developed use of land and other resources, and planning efforts to progressively limit green house gas emissions. It also includes efforts to account for environmental justice in the development of plans and projects