Achieved outcomes and impacts:
A successful implementation of the instrument required both increasing the level of awareness of the Viennese population and building competencies amongst property developers, project developers, architects and planners as well as responsible planning experts of the city administration to deal with urban overheating. However, no more specific information was publicly available on the outcomes and impacts of the Vienna Heat Island Strategy.
Success factors and lessons learned:
Success factors include the early and continuous consideration and involvement of experts (scientific, administrative, practical and political) as well as the inclusion of perspectives of actors from the public and private sectors (generating increased acceptance of measures), the interdepartmental cooperation in implementation on the part of the ministries (a novelty on this scale), and the interdisciplinary cooperation of the relevant project planning areas - architecture, urban planning, building services, building physics, sun protection, climatology, facade greening, facility management, etc. - which proved to be important from the preliminary design phase until later in the project. Raising awareness of the effects and consequences of climate change and the increasing densification of the city on the entire population and their quality of life contributed to increasing acceptance among citizens. Furthermore, the chronological sequence of the planning process and the different levels of decision making and tools were adjusted and implemented in a coordinated way in order to ensure an effective implementation of the Urban Heat Island Strategy.