Abstract Body

In times of increasing urbanisation, constantly growing density of urban settlements and respective effects on city climate, resource consumption and quality of life, sustainable urban development is a crucial element to create liveable and resilient cities. Urban green attracts increasing attention of urban planners as it has numerous positive effects on environment and citizens. It is not only of ecological importance but also of economic and social value for the city although these benefits are often unseen or underestimated by decision makers. And as space is scarce in urban settlements, new, innovative and smart forms of urban greening are required.

The research project VertiKKA, sponsored by the German Federal Ministry of Education and Research, uses a technological approach to increase energy, land and resource efficiency and improve environmental quality as well as quality of life within a city. In collaboration with the City of Cologne (Germany), the project partners develop and analyse a multifunctional green facade element using domestic grey water for irrigation and producing energy with attached photovoltaic elements.

Besides high investment costs and monetary benefits like reductions of incidental housing costs, the VertiKKA-module with its vertical green element provides several uncompensated public benefits. Main ecosystem services, provided by the green VertiKKA module, are regulating services such as local climate and air quality regulation, carbon sequestration and reduction of heat island effects as well as cultural services including impacts on mental and physical health, aesthetic aspects and increased quality of life. Furthermore it provides habitat for species and contributes to biodiversity. To provide arguments and evidence for these public benefits, the economic valuation of the ecosystem services of the VertiKKA module is part of its economic analysis. The assessment comprises a combination of economic valuation methods and participatory approaches. It not only includes a monetary classification of the ecosystem services but also a holistic assessment of qualitative and quantitative benefits as decision basis and road map for urban decision makers.