Abstract
The co-ordination of different sector policies with respect to sustainable development is one of the challenges of planning, and particularly of spatial planning. To fulfil this challenge successfully, spatial planning must ensure full integration and assessment of environmental, social and economic issues. Linking spatial planning with strategic environmental assessment (SEA) is being considered as a crucial condition for sound development, and an important opportunity to move ‘sustainability’ up the ladder of decision making. A research proposal is suggested based on five forms of integration — substantive, methodological, procedural, institutional, and political — which are adopted as a foundation for evaluating current best-practice and defining a framework for integration.