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Pilot 1

Green roof insurances

Pilot lead: IVM
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In this pilot, we studied how insurance can stimulate the adoption of urban nature-based solutions, specifically green roofs, with the ultimate goal to work towards the development of a future European business model for insurance that promotes nature-based solutions. The implementation of green roofs is increasing, but still scarce, even though they provide a range of climate change adaptation and mitigation benefits, such as water management or insulation, as well as multiple co-benefits (heat mitigation, biodiversity improvement, amenities, etc.)



The pilot started with cities in the Netherlands. Our partners IVM and CAS evaluated a climate adaptation strategy implemented by the Dutch insurer Interpolis, which aims to encourage policyholders to adopt green roofs. Furthermore, a broad range of societal benefits of green roofs have been assessed in surveys that include discrete choice experiments among a large sample of urban Dutch residents (N~2000). Based on the assessed benefits of large-scale green roof adoption, a cost-benefit analysis has been performed, which results indicate a positive net economic value generated by green roofs.

The effectiveness of different insurance solutions to promote green roofs, in addition to possible enablers and barriers, has also been examined through surveys and economic experiments. Results show that mixing public subsidies with insurance premium discounts and other information services would be effective in triggering a larger adoption rate of green roofs in the population.

The pilot also seeks to explore whether similar approaches can be applied in insurance markets beyond the Netherlands. During loop 2, we explore the barriers and enablers of green roofs as an adaptation measure promoted by insurers in the Nordic region. Results from the Nordic context highlight that while green roofs are valued for stormwater management, biodiversity and urban aesthetics, their benefits are often perceived as indirect at the individual building scale, weakening the investment case. Key barriers include technical concerns such as roof load capacity, snow accumulation and waterproofing risks, as well as legislative constraints and uncertainty around maintenance responsibilities. Enablers identified include stronger regulatory integration of green roofs into planning frameworks, improved standardisation and monitoring, and the use of public demonstration projects to increase awareness and acceptance.

Finally, the same question is asked in the Mediterranean region in loop 3. In this context, green roofs are more strongly framed as climate adaptation infrastructure, particularly for heat mitigation, indoor thermal comfort and the creation of usable urban spaces. However, barriers include concerns over leakage, maintenance complexity, wildfire risk, and negative perceptions related to biodiversity (e.g. mosquitos), alongside lower insurance uptake overall. Enabling factors include financial incentives, subsidy schemes, and flagship projects, as well as the development of shared data platforms and evidence demonstrating long-term performance and risk reduction benefits at scale.





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