Comparative study of green infrastructure valuation toolkits B£ST and GI-VAL : Increase comprehensiveness of economic green infrastructure valuation assessments

Abstract: There is an abundance of ready-made tools for assessing the economic value of green infrastructure. Each with more or less unique design components and method approaches concerning quantifying and monetizing green infrastructure. Use of a single ready-made tool to support decisions and justify funding of inclusion of multifunctional green infrastructure in urban development may, due to different tools’ various designs and method approaches, risk excluding acknowledgement of relevant ecosystem services. This literature study embodies the logic of comparison by using content analysis method to explore possibilities of producing more comprehensive economic assessments of green infrastructure. This through contrasting content and design features of two such tools: Benefits Estimation Tool, and Green Infrastructure Valuation Toolkit. In addition, it analyses and discusses potential problems and opportunities that may arise when complementing tool A with methods or design features from tool B, and vice versa. Findings suggest that some few methods are similar enough not to constitute a complementary foundation between the tools, but that a combined use of some specific quantification and valuation methods may increase an assessments’ comprehensiveness. Findings also suggest that in combining the tools’ methods inaccuracy and uncertainty of an assessment are likely to increase. The study discusses tool-related problems regarding uncertainty, assessment of social benefits, and perception of value. It concludes that even though mutual complementarity is possible to achieve and in doing so more aspects of GI will be addressed, combining valuation tools in the pursuit of increased assessment comprehensiveness will likely generate problems in terms of assessment inaccuracy. The study may provide aid for developers of green infrastructure valuation tools and for practitioners conducting economic green infrastructure assessments or cost-benefit analyses.