Compactness as a Condition, Compaction as an Ambition—Potentials and Pitfalls of an Interdisciplinary Global Debate on the Compact City

The Compact City is discussed intensively in academia, with ambiguous and inconclusive outcomes regarding its contribution to sustainability. In the practice of urban design and planning, however, compaction is used globally—and largely uncritically—as a tool for sustainable development. Hence, there are large gaps in the communication between different academic disciplines, between academia and practice, and between different geographies. This paper aims to address these gaps by proposing a new way of structuring the Compact City debate and testing it through an extensive literature review as well as take-aways from an international symposium. The hypothetical premise is that the Compact City can be either a measurable condition of degrees and effects of compactness, or an ambition for compaction that is articulated by various actors. For compactness as a condition, it is found that a missing consensus on indicators makes it difficult to address existing research gaps through comprehensive studies. For compaction as an ambition, it is found that while policy analysts are mainly concerned with aligning compaction ambitions for more efficient practical application, urban theorists express fundamental concerns about the desirability of compactness. Drawing on discussions of the symposium, the paper shows that the hypothetical premise is suitable to reveal numerous deficiencies. Central issues include the introduction of multi-scalar approaches and the establishment of indicators beyond urban form. It is concluded that while the Compact City debate has an urgent need for reformation, it has the potential to make pragmatic, holistic, and interdisciplinary contributions to sustainable development.