Marita Wallhagen
Abstract
There is an increased awareness on what benefits application of nature-based solutions in urban environments can have as they deliver ecosystem services, which can make cities more resilient and sustainable. Creating roofs with vegetation, i.e. ‘green roofs’, have the potential to increase the available ecosystem services in urban settings. Still such roofs are not mainly designed and implemented, and knowledge is limited regarding how different designs of green roofs influence the delivery of ecosystem services and the economic costs and benefits for property owners and society. Therefore, the aim of this study was to investigate what impact different designs of green roofs have on delivery of ecosystem services and economic cost and benefits for property owners and society, and how a market driven development could be stimulated. This was studied by designing five different concepts of green roofs using a multidisciplinary design process. Then, possible contributions to different ecosystem services were analysed, and the economic costs and benefit for property owners and society were investigated. These five concepts were combined in a case study in Uppsala, Sweden, to exemplify what impact a green roof could have. The results showed that the five developed concept roofs: the water roof, designed to capture storm water, the energy roof for energy production and vegetation, the farming roof, the biodiversity roof, and the recreational roof, deliver different ecosystem services and at a varying degree. The thickness of the roof substrate and the possibility for people to enter and experience the roof have large impact on the roof’s contribution to the different ecosystem services. Thick substrates increase the possibility to capture storm water and enable abundant vegetation, which contribute to: decreasing heat island effect, pollution prevention,