HAM-Nexus

Cities must transform to face ecological (e.g. climate adaptation, decarbonisation), social (e.g. gentrification, justice, loneliness) and economic (e.g. loss of function of inner-city retail locations) challenges. This requires integrated approaches instead of a sectoral silo mentality. Urban development concepts, master plans and guiding principles should serve as a compass for liveable and sustainable cities. It is important to recognise synergies, interactions and conflicting objectives between thematic areas in order to develop holistic solutions – a challenge in view of the high level of complexity and uncertainty: Urban development is a so-called wicked problem.

However, there is still a gap between conceptual integration in theory and its implementation in practice. The nexus approach helps to visualise cross-sectoral interactions and thus develop robust governance approaches. One field that has received little attention to date is the Housing-Climate Adaptation-Mobility Nexus, or HAM Nexus for short: Housing and mobility are responsible for more than half of urban emissions, and climate adaptation has been added as a new field of action. These areas are closely interlinked and would benefit from close co-operation, yet they are often handeled separately and in different administrative departments.

A look at Vienna, which is considered to be particularly liveable in city rankings, will show how the HAM Nexus is integrated there. The research questions are: What interactions and conflicting goals exist in the HAM Nexus? How has Vienna implemented integrated solutions? How was climate adaptation integrated into existing structures? And: What can German cities learn from the "Vienna way"? A literature review, a research visit to Vienna and expert interviews are planned.